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TABLE OF CONTENTS
LIST OF FIGURES iv
LIST OF TABLES v
ACRONYMS vi
1.0. APPLICATION I
2.0 PURPOSE OF ACTION 1
3.0. BACKGROUND 2
3.1 Feather River Project Description 3
3.3 Initial Response Actions 6
4.0 PROPOSED ACTION AND ALTERNATIVES 9
4.1 Action Alternatives 9
4.2 Proposed Action 10
4.2.1 Initial Response Actions 10
4.2.2 Recovery Actions 16
4.2.3 Supporting Facilities 21
4.2.4 Schedule 25
4.3 No-Action Alternative •
25
5.0 STATUTORY COMPLIANCE AND CONSULTATION 25
6.0 ENVIRONMENTAL ANALYSIS 31
6.1. Scope of the Analysis 31
6.2 General Description of the Project Area 32
6.3 Geology and Soils 33
6.3.1 Affected Environment 33
6.3.2 Environmental Effects 33
6.3.3 Staff Recommendations 36
6.4 Water Quantity and Flow 36
6.4.1 Affected Environment 36
6.4.2 Environmental Effects 38
6.4.3 Staff Recommendations 41
6.5 Water Quality 41
11
6.5.1 Affected Environment 41
6.5.2 Environmental Effects 43
6.5.3 Staff Recommendations 51
6.6 Fisheries and Aquatic Resources 51
6.6.1 Affected Environment 51
6.6.2 Environmental Effects 54
6.6.3 Staff Recommendations 63
6.7 Terrestrial Resources 64
6.7.1 Affected Environment 64
6.7.2 Environmental Effects 69
6.7.3 Staff Recommendations 71
6.8 Threatened and Endangered Species 73
6.8.1 Affected Environment 73
6.8.2 Environmental Effects 77
6.8.3 Staff Recommendations 81
6.9 Cultural and Historic Resources 83
6.9.1 Affected Environment 83
6.9.2 Environmental Effects 88
6.9.3 Staff Recommendations 97
6.10 Recreation 97
6.10.1 Affected Environment 97
6.10.2 Environmental Effects 101
6.10.3 Staff Recommendations 107
6.11 Aesthetics 109
6.11.1 Affected Environment 109
6.11.2 Environmental Effects 109
6.11.3 Staff Recommendations 1.10
6.12 Air Quality 111
6.12.1 Affected Environment 111
111
6.12.2 Environmental Effects 111
6.12.3 Staff Recommendations 113
6.13 Transportation 114
6.13.1 Affected Environment 114
6.13.2 Environmental Effects 114
6.13.3 Staff Recommendations 119
6.14 Noise 119
6.14.1 Affected Environment 119
6.14.2 Environmental Effects 120
6.14.3 Staff Recommendations 121
6.15 Cumulative Impacts 121
7.0 CONCLUSIONS AND RECOMMENDATIONS 123
7.1 Comprehensive Development and Staff-Recommended Measures 123
7.1.1 Staff-Recommended Measures 123
7.2 Consistency with Comprehensive Plans 127
8.0 FINDING OF NO SIGNIFICANT IMPACT 128
9.0 LITERATURE CITED 129
10.0 LIST OF PREPARERS 132
iv
LIST OF FIGURES
Figure 1. Location Map of the Feather River Hydroelectric Project (source: FERC 2007)
4
Figure 2. Transmission lines in the vicinity of Oroville Dam and spillways (source:
Commission staff) 13
Figure 3. Main spillway releases during 2017, including intermittent zero release periods
(source: California DWR 2018) 15
Figure 4. Schematic of Phase 1 and 2 reconstruction plans for the main spillway repairs
(source: California DWR, as modified by Commission staff) 17
Figure 5. Conceptual design of new Oroville emergency spillway (source: California
DWR, as modified by Commission staff) 19
Figure 6. Proposed haul route (red) for additional pervious material from local
commercial quarry (source: Commission staff) 24
Figure 7. Observed flows and sharp reductions (shaded) in the lower Feather River
during the 2017 response period (source: California DWR 2018b) 39
Figure 8. 2017-2018 Lake Oroville Winter Operations Plan (source: California DWR
2018c) 40
Figure 9. Response-period water quality monitoring stations in the Thermalito Diversion
Pool (source: DWR 2018b) 44
Figure 10. Continuous recovery-period water quality monitoring locations (source:
California DWR 2018b) 45
Figure 11. 7.10-2. Turbidity (in Nephelometric Turbidity Units) measured in the Feather
River in the high flow channel (HFC), low flow channel (LFC), Diversion Pool (DP), and.
DP 300 ft. downstream of the dredging in 2017. Note Iog scale on y-axis for turbidity
(source: California DWR 2018b). 47
Figure 12. Water temperatures in the Feather River low-flow channel during the
response period (Source: California Data Exchange Center 2018, as modified by
Commission staff) 50
Figure 13. Hydrograph showing flows in the Feather River during the response period
(Source: California DWR 2018) 57
Figure 14. Lake Oroville Recreational Sites and Facilities (FERC 2007) 99
Figure 15. Recreation Mitigation Locations (source: California DWR 2018b) 104
Figure 16. Recreation Trails Affected by the Spillway Incident (source: California DWR
2018b) 106
Figure 17. Regionally Affected Roads. (source: California DWR 2018b) 116
vi
ACRONYMS
Advisory Council Advisory Council on Historic Preservation
APE Area of Potential Effect
Army Corps U.S. Army Corps of Engineers
C Celsius
California DFW California Department of Fish and Wildlife
California DWR California Department of Water Resources
California SHPO California State Historic Preservation Officer
California SWRCB California State Water Resources Control Board
CFR Code of Federal Regulations
cfs cubic feet per second
Commission or FERC Federal Energy Regulatory Commission
CWA Clean Water Act
DO dissolved oxygen
DPS Distinct Population Segment
DSOD Division of Safety of Dams
D2SI Division of Dam Safety and Inspections
EA Environmental Assessment
ESA Endangered Species Act
ESU evolutionarily significant unit
FEIS Final Environmental Impact Statement
FEMA Federal Emergency Management Agency
FWS U.S. Fish and Wildlife Service
HPMP Historic Properties Management Plan
IPaC Information for Planning and Consultation
kV kilovolt
licensee California Department of Water Resources
msl mean sea level
V
LIST OF TABLES
Table 1. Results of turbidity moniting in the Thermalito Diversion Pool, condcuted
between February 14-August 18, 2017 (source: California DWR 2018b) 46
Table 2. Count of all fishes rescued (live), mortalities (dead), and the Total catch at all
stranding sites between February 27 and March 15, 2017, organized by Family. The total
of each column is summarized in the bottom row (Source: White et al. 2017). 58
Table 3. Total acres of wetland habitat found at project facilities 66
Table 4. Birds protected under the Migratory Bird Treaty Act in the project area. 67
Table 5. Estimated disturbance area for major project activities 70
Table 6. Federally-listed species that may occur in the project area ..73
Table 7. Federally-listed species potentially affected by the response and recover actions.
75
Table 8. Observed and extrapolated numbers of special status species stranded in wet
pools during the Oroville Dam Spillway incident (source: California DWR 2018b). 80
Table 9. Tally of Resource Types within Project 86
Table 10. Summary of license-required recreation facilities 98
Table 11. Summary of Oroville Boat Ramp Useable Lake Elevation Data 103
MW megawatt vii
NRHP National Register of Historic Places
NAHC California Native American Heritage Commission
NHPA National Historic Preservation Act
NMFS National Marine Fisheries Service
NTU nephelometric turbidity units
OWA Oroville Wildlife Area
PA Programmatic Agreement
PG&E Pacific Gas and Electric Company
RCC Roller compacted concrete
Regional Water Board Central Valley Regional Water Quality Control Board
RGP Regional General Permit
Section 106 Section 106 of the National Historic Preservation Act
Section 401 Section 401 of the Clean Water Act
Section 7 Section 7 of the Endangered Species Act
THPO Tribal Historic Preservation Officer
401 certification Water Quality Certification under section 401 of the
Clean Water Act
ENVIRONMENTAL ASSESSMENT
Federal Energy Regulatory Commission
Office of Energy Projects
Division of Hydropower Administration and Compliance
Washington, DC
Feather River Hydroelectric Project
FERC No. 2100-185
1.0. APPLICATION
Application Type: Amendment of Project License
Dates Filed: January 29, 2018, and supplemented February 13, July 16,
and August 1, 2018
Applicant's Name: California Department of Water Resources
Water Body: Feather River
County and State: Butte County, California
Federal Lands: The project occupies federal lands administered by the U.S.
Forest Service and Bureau of Land Management
2.0 PURPOSE OF ACTION
The California Department of Water Resources (California DWR or licensee),
licensee for the Feather River Hydroelectric Project (Feather River Project), requests an
amendment to its project license to reconstruct and modify its main and emergency
spillways at Lake Oroville Dam. The project's spillways were damaged by flooding in
February 2017, and the reconstruction and modifications are required to allow high
inflows to pass downstream of Oroville Darn. California DWR also proposes to
implement various measures to support the initial response to the spillway failure and
proposes to implement additional actions to support the subsequent recovery efforts. The
main spillway rebuild would be an in-kind replacement while the emergency spillway
modifications and the transmission line relocation would be incorporated into the project
via a Iicense amendment.
2
3.0. BACKGROUND
In February 2017, abnormally heavy precipitation resulted in high flows in the
Feather River basin that caused extensive erosion and damage to the main spillway and
emergency spillway area at the Feather River Project's Oroville Dam. California DWR
first observed major damage to the main spillway on February 7, 2017, which included a
large area of foundation erosion and concrete chute loss in the mid-section of the main
spillway. Upon discovery of the main spillway damage, California DWR initiated
consultation with the Commission's Division of Dam Safety and Inspections (D2SI) and
the California Division of Safety of Dams (California DSOD) to coordinate appropriate
response actions. Due to high inflows into Lake Oroville (the project reservoir), and
reduced outflow capacity on the main spillway, Lake Oroville overtopped the adjacent
emergency ogee spillway on February 11, 2017, and caused back-cutting erosion below
the emergency spillway. The back-cutting erosion threatened the stability of the
emergency spillway's crest structure. Unavoidable increased operation of the damaged
main spillway led to the loss of the lower portion of the main spillway chute and caused
significant erosion under and adjacent to the main spillway. Since that time, California
DWR has implemented numerous emergency actions including temporarily relocating
transmission lines away from the damaged main spillway, dredging in the diversion pool
below the spillways, removing sediment near the main spillway, establishing site access,
and initiating reconstruction of the main spillway and fortification of the emergency
spillway.
The actions that followed the spillway failures are divided into two periods: the
"response" period that took place immediately after the discovery of the main spillway
failure on February 7, 2017, and the "recovery" period that covers the timeframe
generally associated with the construction activities at the spillways. The response period
spanned the weeks after the main spillway failure when emergency actions needed to
ensure public safety and environmental protection such as dredging, stabilization
activities, establishing site access, and equipment staging. Because the main spillway
failure was a progressive event that continued to degrade the spillways up until their last
use, we generally consider the response period to have concluded when the main spillway
was shut down on May 19, 2017, at which time the recovery actions began.
The recovery period is ongoing at this time and is expected to continue until
January 26, 2019 (California DWR 2018a). The recovery period includes all activities
involving permanent reconstruction of the damaged facilities, along with the supporting
activities needed to facilitate that reconstruction. Recovery activities began after the
closure of the main spillway on May 19, 2017. Recovery activities include
reconstruction of the main spillway, augmentation of the emergency spillway and
adjacent cutoff wall, relocation of a buried transmission line, and all activities necessary
to support those efforts.
3
Situations involving immediate threats to human health or safety, or immediate
threats to valuable natural resources, must consider whether there is sufficient time to
follow the procedures for environmental review established in the National
Environmental Policy Act. Because the response and recovery actions needed to be taken
immediately due to the severity of the emergency, an environmental assessment (EA)
could not be completed in advance of those activities. This EA, therefore, looks
retroactively at the environmental effects of the response and recovery activities that
preceded California DWR's filing on January 29, 2018. It also looks prospectively at the
potential environmental effects associated with the continuation of the recovery activities
proposed in the licensee's January 29, 2018 filing.
This EA does not investigate the structural adequacy or engineering elements of
the proposed construction activities, which are being assessed separately by the
Commission's D2SI. This EA also does not re-analyze the resources affected by
relicensing activities. Nevertheless, there may be some overlap between the resources
affected by California DWR's proposal and relicensing activities. Those resources are
examined here to the extent the response and recovery activities affected them.
3.1 Feather River Project Description
The Commission issued a 50-year license for the Feather River Project on
February 11, 1957,1 which expired on January 31, 2007. The project has been operating
on an annual license since February 1, 2007.2 The project is Iocated on the Feather River
in Butte County, California, and encompasses 41,540 acres (Figure 1). The project
includes three power plants, two on-river impoundments, and two off-river
impoundments. California DWR's proposal to rebuild and modify its spillways would
occur near the 770-foot high Oroville Dam, with additional supporting
activities to occur in the vicinity of the Thermalito Diversion Pool. Flows pass out of
Lake Oroville in one of four ways: through the six-unit, 645-megawatt (MW) Hyatt
Pumping-Generating Plant; through the gated main spillway; over the ungated emergency
spillway; or through the low-level river outlet valve. Flows pass into the 320-acre
Thermalito Diversion Pool, which is impounded by the 143-foot-high Thermalito
Diversion Dam, located about four miles downstream. Other project features include:
the Thermalito Power Canal leading off-river to the Thermalito Forebay and Forebay
Dam; Thermalito Pumping-Generating Plant, and Thermalito Afterbay and Afterbay
Order Issuing License (17 FPC 262).
2 See Notice of Authorization for Continued Project Operation, issued
February 1, 2007 in Project No. 2100-000.
4
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Figure 1. Location Map of the Feather River Hydroelectric Project (source: FERC 2007)
5
Darn; the Feather River Fish Hatchery and fish barrier dam; the Oroville Wildlife Area
(OWA); transmission lines, and various recreational facilities.3
3.2 Project Operation
The project facilities are part of the State Water Project, a water storage and
delivery system of reservoirs, aqueducts, power plants, and pumping plants. The main
purpose of the State Water Project is to store and distribute water to supplement the needs
of urban and agricultural water users in northern California, the San Francisco Bay Area,
the San Joaquin Valley, and southern California. The project facilities are also operated
for flood management, power generation, water quality improvement in the Sacramento-
San Joaquin Delta, and recreation and fish and wildlife enhancement.
Winter and spring runoff, to the extent available, is stored in Lake OrovilIe for
release to the Feather River, as necessary, to meet downstream water demands and
minimum instream flow requirements. Water can also be stored in Lake Oroville and the
other project impoundments over a shorter time frame (over days or hours) to meet power
objectives. Typically, under normal and wetter conditions, Lake Oroville is filled to its
normal maximum annual surface elevation of 901 feet mean sea level (nisi) in June and
then.lowered as needed to meet downstream requirements until reaching its minimum
level in December or January. During and following dry years, the reservoir may be
drawn down more, and may not fill to desired levels the following spring. During wetter
hydrologic conditions, Lake Oroville is managed to control downstream flooding. The
U.S. Army Corps of Engineers (Army Corps) requires Lake Oroville to be operated to
maintain up to 750,000 acre-feet of storage space to capture significant inflows for flood
control.
The project is also designed to use water in excess of the downstream flow
requirement for pumping water back into the Thermalito Forebay, and then into Lake
Oroville during off-peak hours. This water is then released again during on-peak hours
when power values increase. The project operates in a pump-back mode year-round, and
this operation can cause Lake Oroville to fluctuate 1 to 2 feet daily. Weekly fluctuations
in Lake Oroville range from 2 to 6 feet and may be as great as 9 to 11 feet over a several
week period.
Because the Thermalito Forebay, Power Canal, and Diversion Pool below Lake
Oroville are all designed to share the same operating water level (and are essentially the
same hydraulic system), the water levels in each of these facilities rise and subside in
unison. The system does not typically fluctuate much on a daily basis. During the
3 See a detailed description of the project's facilities and operation in the Final
Environmental Impact Statement for the Oroville Facilities Project, issued May 18, 2007,
in Project No. 2100-052, at pages 13 through 25 (FERC 2007).
6
summer over a Ionger period of time, the water level is generally cycled down 2 to 4 feet
during the middle of the week and then refilled by the weekend. During the winter, it
may fluctuate more.
The Thermalito Afterbay is operated to meet multiple requirements, including
regulating inflow from the Thermalito Pumping-Generating Plant, providing water for
withdrawal during pump-back operation, and releasing water through the Thermalito
Afterbay outlet to the Feather River. The Thermalito Afterbay is also the location where
diversions are made to meet the Feather River service area irrigation entitlements.
3.3 Initial Response Actions
Following the initial observation of damage and erosion at the main spillway on
February 7, 2017, California DWR took various actions to secure the project facilities
and to minimize effects to environmental resources. Specifically, on February 8, 2017,
California DWR, in preparation for the potential need to use the emergency spillway,
cleared the area below the spillway of trees, rocks, and debris. In preparation for flows
over the emergency spillway, California DWR also grouted and installed rocks and
shotcrete in some areas below the emergency spillway. In association with increased
inflows into Lake Oroville on February 9, 2017, California DWR increased releases
through the main spillway, causing additional damage to the main spillway chute and
significantly eroding the hillside. Due to the elevated turbidity levels in the Feather
River, California DWR assisted the California Department of Fish and Wildlife
(California DFW) in relocating juvenile Chinook salmon and steelhead from the
downstream Feather River Fish Hatchery, which was compromised by the elevated
turbidity in its water supply system from the river. The juvenile fish were relocated to
the Thermalito Afterbay Hatchery Annex and were released into the Feather River and
San Francisco Bay in 10 events extending from March through May 2017. California
DWR also fortified the Hyatt Power Plant to prevent backwatered areas from flooding
and compromising the powerhouse. California DWR ceased powerhouse operations on
February 9, 2017, due to backwater effects from debris accumulation below the main
spillway.
On February 11, 2017, increasing inflow to Lake Oroville caused reservoir levels
to exceed the emergency spillway elevation and water began passing over the emergency
spillway for the first time in project history. Flows passing over the emergency spillway
caused significant erosion to the bare hillside below the emergency spillway. This was
coupled with ongoing erosion of the main spillway since the initial February 7, 2017
observation, thereby filling in portions of the Thermalito Diversion Pool with additional
sediment. The sediment deposition in the spillway caused the ThermaIito Diversion
Pools to rise above safe operating levels for the Hyatt Power Plant, rendering it out of
service and prompting California DWR to fortify the powerhouse to prevent flooding.
7
In response to rapidly progressing uphill erosion below the emergency spillway
and the potential for emergency spillway failure, residents downstream of Oroville Dam
were ordered to evacuate the area on February 12, 2017. After using both spillways to
reduce reservoir levels, the mandatory evacuation order was reduced to an evacuation
advisory warning on February 14, 2017, and downstream residents were allowed to return
to the area.4 On February 16, 2017, California DWR began intense efforts to remove
debris and sediment from the Diversion Pool. The removal efforts were implemented
using land-based and barge-based excavators. In addition, California DWR graded,
fortified, and placed shotcrete on a large area of the eroded hillside below the emergency
spillway.
As inflows and lake levels receded, California DWR ceased operation of the main
spillway to facilitate sediment removal and inspect damage. The most notable of these
reductions occurred on February 27, 2017, when spillway releases decreased from 60,000
cubic feet per second (cfs) to 0 cfs. Due to the abrupt flow reductions in the Feather
River and potential environmental impacts, California DWR conducted operations to
rescue stranded fish in collaboration with California DFW. Additional fish rescues
occurred in the Feather River following subsequent flow reductions when the main
spillway was taken out of service. Additional abrupt flow reductions occurred four times
until May 19, 2017, when the main spillway was taken out of service for the remainder of
the year.
The Hyatt Power Plant returned to service on March 3, 2017 and was used in
conjunction with the main spillway to more fully manage Lake Oroville storage levels,
until being taken out of service on May 19, 2017. California DWR also reactivated its
river valve operation capability at the base of Oroville Dam, which added additional flow
release capacity. In a separate proceeding, California DWR proposed to permanently
relocate its primary above-ground transmission line from the Hyatt Power Plant to the
Table Mountain Substation. California DWR had been utilizing a temporary
transmission line due to potential erosion concerns to the transmission line towers in the
vicinity of the main spillway. California DWR's application was approved on August 23,
2017.5 The California DWR transmission line was relocated concurrently with a Pacific
Gas and Electric Company (PG&E) above-ground transmission line in the same area.
PG&E filed its request to relocate its transmission line, with the Commission for approval
on June 23, 2017. The Commission approved the request on August 2, 2017.6
4 The evacuation advisory warning was later lifted on March 21, 2017.
5 Order Amending License, Revising Project Description, and Amending Project
Boundary (160 FERC ¶ 62,168).
6 Order Approving Non-Project Use of Project Lands and Amending License (160
8
Concurrently, at the Commission's direction and with its approval, California
DWR convened an independent Board of Consultants to design and assess remedial
options for the main and emergency spillways, and to develop measures to reliably
operate the project during the emergency situation and reduce risk.' At the
Commission's direction, California DWR also convened an independent forensic review
team to investigate the cause of the spillway failure. The Commission worked closely
with California DWR and Board of Consultants to develop a new design for the two
spillways, and with the independent forensic team to identify the causes of the spillway
failure. The independent forensic team issued its final report on January 5, 2018. Among
the findings of the report, the team concluded:
"There was no single root cause of the Oroville Dam spillway
incident, nor was there a simple chain of events that led to the
failure of the [main] spillway chute slab, the subsequent
overtopping of the emergency spillway crest structure, and
the necessity of the evacuation order. Rather, the incident
was caused by a complex interaction of relatively common
physical, human, organizational, and industry factors, starting
with the design of the project and continuing until the
incident."8
FERC ¶ 62,118).
7 Cal. Dep't of Water Res., Docket No. P-2100-000 (Feb. 13, 2017) (delegated
letter order) (requiring that a board of at least five independent technical experts review
then-current measures and conditions; risk reduction measures; all proposed remedial
options for both spillways; long-term, permanent modifications and project operations;
and other issues); Cal. Dep't of Water Res., Docket No. P-2100-000 (Feb. 21, 2017)
(delegated letter order) (approving five-member board and further specifying the board's
responsibilities).
8 France, J.W., A.A. Alvin, P.A. Dickinson, H.T. Falvey, S.J. Rigbey, J.
Trojanowski. (2018). Independent Forensic Team Report— Oroville Dam Spillway
Incident, issued January 5, 2018.
9
4.0 PROPOSED ACTION AND ALTERNATIVES
4.1 Action Alternatives
California DWR developed its proposed action in consultation with the
independent Board of Consultants, the California DSOD, and the Commission's D2SI.
During the development of alternatives, California DWR considered various options for
the location and design of spillway structures to pass high inflows out of the project's
Lake Oroville to ensure public safety for residents downstream of the project. While
several alternatives were considered, the emergency nature of the situation was not
conducive to developing detailed plans for each alternative. California DWR's
development of a final alternative, described in section 4.2 below represents the final
design after the continuous elimination of infeasible main and emergency spillway design
alternatives, and was constrained by California DWR's inability to select, prepare, and
develop a new main spillway site in an expeditious mariner.
Among the elements considered during the design phase were current engineering
standards, conveyance capacity, site location, geological conditions, material use, seismic
stability, cost, construction time, and environmental concerns. At the main spillway,
California DWR opted to use the existing spillway gate structure as a starting point for its
design, primarily due to the excessive time required to build a new gate structure at an
alternate site. Once it decided to utilize the footprint of the existing main spillway,
California DWR considered various designs and materials for bypassing flows past the
large eroded area created by the main spillway failure and constructing a functional
spillway chute. Similarly, the enhancements proposed to the emergency spillway were
designed to adequately pass high inflows, while being able to be constructed in a
reasonable timeframe.
As demonstrated by regular construction authorization letters from the
Commission's D2SI, Commission staff concur that the California DWR's proposal
outlined below represents the preferred alternative for restoring the project to its
operational capacity. The action alternative allows for expeditious repair of the main
spillway by using the existing footprint and orientation of the damaged main spillway,
and adheres to modern engineering standards. In a like manner, the emergency spillway
enhancements allow for its continued use, while adhering to modern engineering
standards.
•
Nevertheless, we note that in its January 12, 2018 letter to the Commission's
D2SI, California DWR states that it is initiating a Comprehensive Needs Assessment to
identify additional measures to bolster the safety and reliability of Oroville Dam and the
appurtenant structures. Among the tasks of the assessment, California DWR and an
Independent Review Committee would review: alternatives to restore spillway design
capacity to pass the probable maximum flood; operational needs to support development
10
of alternative reservoir outflow enhancements; flood control outlet enhanced reliability;
alternatives for the low-level outlet; Oroville Dam embankment reliability and
improvements; and instrumentation and monitoring for the Oroville Dam complex.
California DWR states that this effort would conclude by December 31, 2019, resulting
in a list of prioritized darn safety and operational reliability needs. California DWR
further states that it may identify projects that significantly benefit public safety and
reduce risk. California DWR would submit its identified projects for Commission and
other agency review and authorization. The 2018-2019 Comprehensive Needs
Assessment is beyond the scope of this EA.
4.2 Proposed Action
California DWR proposes to implement a set of response and recovery actions
with the end goals of rebuilding the main spillway and modifying the emergency
spillway. The analysis below discusses several actions under each end goal. California
DWR also proposes to implement measures to prevent or mitigate for any adverse effects
to environmental resources. Altogether, California DWR proposes to rebuild the main
spillway and modify the emergency spillway in two phases, and completing work by
January 2019. Due to the emergency nature of the spillway failure, California DWR
completed urgent repairs to the main spillway by reconstructing it back to a temporarily
functional state prior to the start of the winter season in November 2017.9 California
DWR would subsequently complete restoration of the main spillway and additional
enhancements to the emergency spillway by January 2019.
California DWR would also relocate a buried transmission line between the Hyatt
Power Plant and Thermalito Diversion Powerhouse. The main spillway rebuild would be
an in-kind replacement, while the emergency spillway modifications and the transmission
line relocation would be incorporated into the project via a license amendment. This EA
retroactively examines the urgent work completed during 2017, but also analyzes the
proposed work during the 2018 construction season.
4.2.1 Initial Response Actions
As defined above, the initial response period included the actions that California
DWR implemented to respond to the unanticipated main spillway failure and erosion of
the emergency spillways. The response period encompassed the February 7 to May 19,
2017 period and included California DWR's efforts to: stabilize the main spillway;
prepare for use of the emergency spillway; temporarily relocate transmission lines;
dredge eroded material from the Thermalito Diversion Pool; manage inflow to the
9 The 2017 construction work was developed and authorized in consultation with
the Commission's D2SI.
11
project; construct access roads; and implement other supporting activities. These
activities are described in detail below.
Preparation and Use of the Emergency Spillway
Shortly following the initial discovery of erosion at the main spillway on
February 7, 2017, California DWR began preparing for potential use of the emergency
spillway, located west and adjacent to the main spillway. To prevent additional material
from washing into the Thermalito Diversion Pool, California DWR cleared the hillside
below the emergency spillway of trees, vegetation, rock, and debris, and used the cleared
hillside and seasonal streambed to convey flows over the emergency spillway. In total,
California DWR cleared approximately 40 acres in preparation for the use of the
emergency spillway.
Following the use of the emergency spillway, California DWR constructed new
access roads below the emergency spillway to replace those washed out from use of the
emergency spillway. In the extensive areas where erosion had occurred, California DWR
filled scour holes with large diameter rock at a rate of 1 ,200 tons of material per hour,
using helicopters and heavy construction equipment.'° California DWR also graded and
excavated the eroded hillside, followed by the placement of approximately 107,000 cubic
yards of concrete to prevent any future additional erosion.
Temporary Transmission Line Relocation
Because of the threat of erosion and collapse of the transmission line towers near
the main spillway and the potential to lose operational ability of the Hyatt Power Plant,
California DWR needed to immediately reroute its Oroville-Table Mountain
Transmission Line. California DWR's original Oroville-Table Mountain Transmission
Line ran from the Hyatt Pumping-Generating Plant, in a northwest direction, across
Thermalito Diversion Pool and the faces of both spillway areas. The original Oroville-
Table Mountain Transmission Line then turned due west toward the Table Mountain
substation, located approximately 7 miles away (Figure 2). California DVVR constructed
a temporary (shoofly) transmission line alignment that deviated from its original
alignment midway across the spillways, to an area immediately below the main spillway
gates where it then continued in a northwest direction, until it rejoined the original
Oroville-Table Mountain Transmission Line (Figure 2). The temporary DWR
transmission line was approximately 1.4-miles-long, and resulted in a denuded corridor
approximately 200 feet wide.
10 https://www.water.ca.gov/What-We-Do/Emergency-Response/Oroville-
Spillways/Background (accessed June 20, 2018).
12
Similarly, PG&E's Table Mountain-Palermo Transmission Line was in the path of
the emergency spillway flow and would have been damaged from water flows if the
emergency spillway was used extensively. PG&E's original Table Mountain-Palermo
Transmission Line ran in a primarily north-south direction before turning west towards
the Table Mountain substation, west of the main spillway. The PG&E transmission line
was located on land within the project boundary through an existing easement between
the two entities. PG&E temporary transmission line deviated from its permanent
alignment at a point on the south bank of the diversion pool near the main spillway
confluence, and was relocated further away from the spillways before rejoining the
original Table Mountain-Palermo line alignment (Figure 2). The PG&E temporary
shoofly transmission line was approximately 0.9-miles-long and resulted in a mostly
denuded corridor approximately 100 feet wide. Both the California DWR and PG&E
also constructed short access roads and work pads to facilitate installation of transmission
towers or electrical poles.
Main Spillway Response
At the main spillway, California DWR implemented urgent actions to stabilize the
damaged spillway and to create access to the spillway site. California DWR established a
network of construction access roads to the spillway site, which primarily consisted of
short (less than 1/4-mile long) branches off the previously existing access roads near the
main spillway. In the process of road construction, California DWR removed trees and
vegetation in an approximately 30-foot wide road corridor. California DWR also
constructed crane pads along the main spillway to facilitate the mobilization of
equipment to the main spillway site, resulting in 0.83 acres of land disturbance. As flow
releases from the main spillway subsided, California DWR blasted and graded unstable
slopes near the main spillway. This occurred primarily along the left (eastern portion) of
the main spillway, along an approximately 1,300-foot length of eroded hillside parallel to
the main spillway. During the temporary spillway outages, California DWR installed
shotcrete and anchors at the end of the damaged spillway slab to prevent further erosion
of the underlying spillway material.
13
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Dredging
-ii
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just east of
Severe erosion ensued after the failure„ of the mainet .spiliway and use of the
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Near the main spillway,
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(FERC Project No. 2088), impairing operations of both facilities, California DWR
14
dredged eroded material from Thermalito Diversion Pool in the areas where outflow from
the main and emergency spillways occur. California DWR dredged the material from
several barge-based excavators and from the shore of the diversion pool using long-
armed excavators beginning on February 15, 2017, and continued through the recovery
phase (discussed below), concluding in fall 2017. The material was deposited in three
prominent areas including a laydown area immediately west of the Thermalito Diversion
pool spillway, a new spoil pile area southwest of the emergency spillway, and a historical
spoil pile along the Thermalito Diversion Pool area across from the Hyatt Power Plant
tailrace. California DWR estimates that approximately 2.2 million cubic yards of rock,
concrete fragments, and hillside were eroded and deposited in the diversion pool. During
the initial response phase, approximately 1.4 million cubic yards of debris was removed
from the diversion pool.
Flow Management
As part of its February 7 to May 19, 2017 response activities, California DWR
managed flow releases from the main spillway for the purpose of passing inflows and
preserving the structural integrity of the remaining portion of the main spillway. Due to
the uncertainty associated with main spillway releases exacerbating erosion of the
spillway, California DWR implemented a range of spillway flow releases. Releases from
the main spillway were also critical, due to California DWR's inability to release water
from the Hyatt Power plant, which was offline until March 3, 2018.
During the response period, California DWR released flows from the main
spillway up to 100,000 cfs, and as low as 0 cfs (Figure 3). California DWR also varied
the ramping rate associated with the releases from small incremental steps to as much as
60,000 cfs per hour when dropping flows to zero." The large sharp flow reductions
occurred to prevent the lower spillway releases from head-cutting remaining portions of
the main spillway. Downstream of the Oroville Dam, California DWR managed flow
releases from the Thermalito Diversion Dam and Thermalito Afterbay Dam to pass flows
from high flow spillway releases and to maintain flows for aquatic resources in the
Feather River during reduced or no flow releases from Oroville Darn.
During the response period, there were four periods in which California DWR
ceased releases from the main spillway. The first main spillway outage occurred during
February 28 to March 16, 2017. During this time, California DWR provided minimum
flows to the lower Feather River from water stored in the Thermalito Diversion Pool.
This occurred until March 3, 2018, when Hyatt Power Plant came back online.
" For reference purposes, the mean daily flow in the Feather River is
approximately 500-2,100 cfs, depending on the month (FERC 2007). The highest main
spillway release occurred during exceptionally high inflows in 1997, during which flows
through the main spillway were approximately 150,000 cfs.
15
California DWR also exercised two additional main spillway outages on March 28 to
April 13, 2017 and May 2-9, 2017. During these final two outages, California DWR met
minimum flow requirements using the Hyatt Power Plant, which was back online.
California DWR also made releases from the main spillway, in its damaged state, on
February 7-27, March 17-27, April 14-May 1, and May 10-19, 2017. By using the
turbines to control the reservoir level, the main spillway would remain unused through
completion of construction.
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(source: California DWR 2018)
Roads
In addition to the roads used for access to the immediate main and emergency
spillway areas, California DWR utilized or enhanced existing roadways in the project
area to facilitate initial response efforts. Among the existing roads, California DWR
utilized roads under the control of the City of Oroville and Butte County. These
roadways were primarily located between state highway 70 and the main spillway site to
the east. These existing roadways were used to transport construction materials and
equipment, and for site access. California DWR provided a detailed list of roadways
affected, including estimates for repairs from impacts associated with travel by
construction equipment. California DWR also included specifications for a temporary
traffic control plan in its filing, which it would require its contractors to implement as
part of its construction efforts. The impacts of construction transportation in the project
area are discussed further in section 6.13-Transportation.
16
4.2.2 Recovery Actions
Main Spillway Repairs
California DWR proposes to reconstruct the main spillway in two phases over two
construction seasons. The first phase of construction in 2017 included construction
activities on the entirety of the main spillway, except the uppermost 730-foot section
below the spillway gates (Figure 4). During this first construction phase (May to
November 2017), the subsequent 870-foot portion of the upper spillway section was
demolished, excavated, and replaced with a reinforced structural concrete floor and walls.
The 1,050-foot portion of the middle spillway chute was also partially reconstructed to a
functional status during 2017. Construction activities on the middle spillway portion
during 2017 included: blasting, demolition, and excavation for roller-compacted concrete
(RCC) fill; constructing concrete backfill and RCC foundation for the reinforced concrete
chute; and constructing RCC walls. California DWR reconstructed the 350-foot lower
portion of the main spillway by removing the remaining portions of the spillway,
constructing cutoff walls, and installing structural concrete. In addition to the removal of
damaged concrete, California DWR laterally excavated soil and weathered rock along the
right and left sides of the spillway (which wete unstable), due to the severe erosion from
the main spillway failure. Preparation work for the repairs on the main spillway included
selective demolition and removal of the damaged spillway, soil, rock, grout and shotcrete.
California DWR also conducted controlled blasting of the damaged spillway. In addition,
California DWR cleaned the spillway foundation with pressure washers and compressed
air, prior to the addition of dental concrete, leveling concrete, RCC, structural concrete,
and a drainage network.
The second phase of construction would consist of replacement of the remaining
730-foot portion of the upper spillway during the 2018 construction season (May 2018 to
November 2018). The upper spillway would be removed and replaced with structural
concrete and secured to the underlying hillside. The replaced spillway portion would
follow the same alignment as the previous spillway, and would be replaced all the way to
the spillway radial gate area. In addition, California DWR would remove the RCC walls
from the 1,050-foot section of the middle spillway and replace them with structural walls.
California DWR would also remove the surface layer of RCC on the middle spillway,
and install structural concrete on the reduced RCC surface. Finally, California DWR
would hydro-blast and resurface the energy dissipaters (dentates) at the bottom of the
main spillway.
17
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Figure 4. Schematic of Phase 1 and 2 reconstruction plans for the main spillway repairs
(source: California DWR, as
modified by Commission staff)
Emei-gencv Spillway Repairs
. •
. .
California DWR proposes leaveof the existing emergency
to the majority . .
in
overflow spillway place, andto • . tofortify the existing
install additional measures
structure and prevent downstreamerosion
during any
future use. California DWR would
of the spillway in place,
spillway comprising the eastern portion
leave the existing ogee
. California DWR would fortfy the ogee
along withshotcrete armori
ng
i the downstream
18
overflow spillway by installing a RCC concrete buttress and splash pad on the
downstream side of the emergency spillway (Figure 5). The RCC buttress would be a
curved topped berm with a drainage system, placed against the emergency spillway
monoliths to increase stability. California DWR would also remove and replace the
broad-crested weir (or crest cut-off wall), comprising the western portion of the
emergency spillway. The western structure would be removed and replaced with a new
10-foot deep, 2'/2-foot-wide reinforced concrete cutoff wall. Construction activities
associated with the cutoff wall include: selective asphalt demolition and removal of the
previous broad-crested weir; excavation of a 10 x 2.5-foot ditch; cleaning the trench of
loose material; steel lattice reinforcement; and concrete pouring and shaping.
In addition to the improvements along the emergency spillway, California DWR
would install a RCC splash pad behind the buttress and emergency spillway consisting of
a 5-10-foot-thick RCC apron. The RCC splash pad would be stair-stepped to dissipate
energy, and would be contoured to direct flows to a main armored drainage channel.
Additionally, California DWR would install a vertical secant pile cutoff wall at the
downhill end of the splash pad, and approximately 750-feet downslope of the emergency
spillway. Secant pile wall construction would involve selective demolition of the
previous emergency rock slope protection, drilling holes for secant piles, concrete
reinforcement installation, and steel reinforcement above the secant piles. The
emergency spillway modifications commenced during the 2017 season, and would be
completed during the 2018 construction season.
19
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Figure 5. Conceptual design of new Oroville emergency spillway (source: California
DWR, as modified by Commission staff)
Relocate Buried 13.8 kV Power/inc and Buried Fiber Optic Communication System
California DWR proposes to relocate a portion of its buried 13.8-kV transmission
line,12 located between the Hyatt Power Plant switchyard and the Thermalito Diversion
Dam Powerhouse. California DWR would also relocate a portion of a buried fiber optic
communications line, which runs parallel to the transmission line. California DWR
would abandon in place, an approximately 3.5-mile buried sectionof the transmission
line. As a replacement, it would relocate an approximately 3.8-mile section of the buried
line starting at the Hyatt Power Plant, and continue almost to the Thermalito Diversion
Power Plant, where it would join with a pre-existing section of buried line approximately
0.8 miles north of the powerhouse. The new buried fiber optic communications line
would be co-located with the relocated buried transmission line along the entirety of the
route, and would span the entire distance between the Hyatt and Thermalito Diversion
12 The project license refers to this transmission line as a 15-kV line, but we use
the 13.8-kV specification provided by California DWR, which also corresponds with the
current typical voltage for such a facility. See Order Amending License, Revising Project
Boundar-y, and Amending Project Boundary (160 FERC 1162,168), issued August 23,
2017.
20
Power Plants. Part-way between the Hyatt and Thermalito Diversion Power Plants, the
buried fiber optic line would diverge south outside of the project boundary, where it
would connect to the Oroville Field Division facility, located approximately 2 miles to
the south.13 Construction activities involved with the installation would include the use
of excavators, trenching equipment, shoring equipment, loaders, and dump trucks.
Permanent Relocation of PG&E and DWR Transmission Lines and Removal of the
Temporary (shoofly) lines
In separate Commission proceedings, California DWR14 and PG&E15 permanently
relocated their transmission lines that were re-routed temporarily during the response
phase. Following the activation of its re-routed 230-kV Table Mountain—Palermo
Transmission Line, PG&E removed its temporary line and 13 temporary steel poles by
helicopter. In addition, PG&E crews removed rock at each tower location that was used
as backfill, and hauled it offsite. Similarly, California DWR removed the towers
supporting its temporary transmission lines after reactivating its Oroville-Table Mountain
Transmission Line. California DWR utilized helicopters, cranes, bulldozers, and
excavators to facilitate the removal process, with California DWR creating temporary
earthen crane pads to remove concrete footings.
Radial Gate Repair
California DWR proposes to repair components of the Oroville and Thermalito
Diversion Dam radial gates that were damaged during the spillway failure. Repair
activities would include repair of the radial gates and replacement of tension rods, seals,
'3 The divergent fiber optic line leaves the project boundary at this point, and is
being analyzed and permitted separately by California DWR. Therefore, it is not given
consideration in this analysis.
14 The Oroville-Table Mountain Transmission Line has since been permanently
rerouted outside of the response and recovery area. See Order Amending License,
Revising Project Description, and Amending Project Boundary, 160 FERC ¶ 62,168
(issued August 23, 2017).
15 The Table Mountain-Palermo Transmission Line has since been permanently
rerouted away from the response and recovery area. See Order Approving Non-Project
Use of Project Lands and Amending License, 160 FERC 1162,118
(issued August 2, 2017).
•
21
and other hardware.16 In order to facilitate repairs, California DWR would create or
improve access roads on the lakeside of the main spillway.
4.2.3 Supporting Facilities
In order to support the spillway repair work, California DWR would install
transportation facilities, material preparation facilities, laydown areas, and construction
support facilities. The following describes those various facilities that have been, or will
be used to support the response and recovery efforts.
Roads
In addition to the road construction and enhancement activities in the response
phase, California DWR enhanced Burma Road, located along the north side of the
Thermalito Diversion Pool. Specifically, the existing Burma dirt road was widened to a
width of 28 feet to accommodate larger trucks and heavy equipment, which includes a
22-foot wide roadbed and flanking V-ditches. California DWR also fortified Burma
Road along two stream crossings, where multiple box culverts were installed and filled
over with road base to allow heavy equipment and materials to access the spillway repair
area. The road construction along Burma Road also necessitated the replacement of
several culverts under the roadway for seasonal streams, vegetation trimming, and rock
enhancement to the roadbed. Based on construction needs, California DWR further
proposes to widen the roadway to 30 feet around curves, extend existing culverts, trim
additional vegetation, and place additional fill to accommodate large vehicles around
tight curves along Burma Road. Finally, California DWR proposes to pave, widen, or
perform maintenance at roadways leading to Burma Road, including Power Canal and
Cherokee Road. In all instances above, California DWR would utilize excavators, dump
trucks, graders, bulldozers, water trucks, pavement equipment, rollers, and chainsaws to
construct or enhance access to the spillway site. In total, California DWR estimates that
a total of 28.31 miles of roads would be utilized for site access during the response and
recovery phases.
Concrete Batch Plants
Work on the spillways would be supported by the use of a rock processing plant
and multiple on-site concrete plants. California DWR created a rock processing plant,
located east of the main spillway and which, primarily utilizes rock and soil dredged from
the Thermalito Diversion Pool to provide aggregate products for RCC production.
16 The radial gate repairs at the Thermalito Diversion Dam were previously
proposed under a separate filing, dated July 17 and August 22, 2017. By letter dated
September 1, 2017, these activities were approved as regular maintenance by the
Commission's Division of Dam Safety and Inspections.
22
California DWR also constructed a RCC batch plant on site to utilize material dredged
from the Thermalito Diversion Pool, to the extent possible. The RCC batch plant is
located in the spillway boat ramp parking lot, but RCC production operations would later
shift downhill to the vicinity of the emergency spillway construction area. In addition,
California DWR created a structural concrete batch plant on site, which utilizes material
dredged from the Thermalito Diversion Pool. The structural concrete batch plant is
located on the east side of the main spillway, near the bottom portion of the spillway.
The structural concrete plant is also co-located with the aggregate rock processing plant,
which includes the processing plant, crushing operations, conveyors, and rock washing
facilities. California DWR states that following the completion of aggregate production,
California DWR would restore the rock processing plant area to pre-construction
contours. Finally, California DWR states that it would utilize an off-site plant to produce
additional concrete for various construction needs. In total, California DWR estimates
that it would utilize 7.47 acres of land for the concrete batch plants.
Laydown/Staging/Support Areas
To facilitate logistical support, California DWR would utilize existing project
facilities or designate new areas for storage and staging of equipment and temporary
office deployment. California DWR converted the spillway boat ramp recreation area
and parking lot into a temporary worker support facility, with trailered offices for
California DWR, contractor, and other agency staff Similarly, California DWR is
utilizing the Oroville Dam Overlook Day Use Area as a temporary equipment staging
area, California DWR also expanded an existing laydown area just to the east of the
main spillway gates to a 7-acre site for staging of construction materials and equipment.
Finally, California DWR is utilizing the Thermalito Diversion Pool Day Use Area as a
staging area primarily for equipment associated with dredging activities. The site is also
being used as a deposit area for material dredged from the diversion pool.
Additional Dredging
California DWR continued debris removal efforts during the recovery phase of
work, primarily through in-water debris removal efforts. As of November 2017,
California DWR had removed approximately 2 million cubic yards of material from the
Thermalito Diversion Pool. Nonetheless, California DWR estimates that approximately
320,000 cubic yards of deposited material would remain in the diversion pool.'
" The material deposited in the Diversion Pool is an estimated volume and when
saturated, is approximately 20 percent greater than the material originally situated in the
hillside adjacent to the main spillway.
23
Borrow Areas
California DWR is utilizing on-site and off-site locations as borrow areas for
concrete production activities. The primary borrow area is located to the east of the main
spillway. At this location, California DWR would remove approximately 380,000 cubic
yards of material, resulting in a project footprint of 80 feet vertical depth and an area of
7.1 acres. However,.California DWR is also using material dredged from the Thermalito
Diversion Pool and stored at the spoil pile west of the emergency spillway for concrete
production. Finally, California DWR would import approximately 25,000 cubic yards of
gravel from a local commercial vendor to use as pervious backfill material in the
reconstruction of the main spillway. The material would be sourced from a commercial
quarry located on Table Mountain Boulevard in Oroville, CA, and transported to state
highway 70, and continue to Oro Darn Boulevard and Canyon Drive, before arriving at
the worksite (Figure 6). The material would be hauled during both day-time and night-
time hours, beginning in in late August 2018 through January 2018, and would involve
approximately 1,400 round-trips. To mitigate impacts to noise, air quality, and
transportation resources, California DWR would: cover vehicle to prevent dust; install
track out plates where vehicles exit the construction site onto paved roads; limit truck
idling to no more than 5 minutes when not in use; schedule material hauling to off-peak
hours, when possible; implement required asbestos control measures; comply with
applicable air quality permits; and adequately maintain all hauling trucks.
Other Supporting Work
California DWR implemented other miscellaneous activities to support the
response and recovery effort. Along the northern portion of the Thermalito Diversion
Pool, California DWR installed a barbed wire boundary fence to prevent cattle from
entering the work area and to ensure safe use of Burma Road. As part of the work, the
California DWR selectively removed or trimmed trees and vegetation within a 6-foot-
wide section of project land, across from the spillway boat ramp to Morris Ravine.
California DWR also shored bridges, conducted geological monitoring for construction
activities, installed an intake water system, and set up wheel wash stations for
construction vehicles to prevent introduction of noxious weeds.
24
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commercial quarry (source; Commission staff)
25
4.2.4 Schedule
Due to the urgent public safety concerns associated with the main spillway failure
and emergency spillway area degradation, California DWR implemented the above
response actions between February and May 2017 (prior to the completion of this
analysis). California DWR also began the first of two phases of recovery effort
construction during 2017 by bringing the main spillway back to a functional (but partially
reconstructed) status on November 1, 2017. This included construction of a temporary
RCC section in the middle span of.the main spillway and full reconstruction of an
additional portion of the middle and lower main spillway. California DWR also began
fortifications to the emergency spillway area in July 2017. The second phase of
construction would occur in 2018, during which California DWR would reconstruct the
upper portion of the main spillway and complete full replacement of the middle RCC
main spillway section with structural concrete. During the second phase of construction,
California DWR would also complete work on the emergency spillway. Specifically,
California anticipates completion of construction of the project spillways by
January 26, 2019. Though not stated in California DWR's application, we expect
additional closeout activities and demobilization to occur during early 2019.
4.3 No-Action Alternative
Under the no-action alternative, California DWR would have left the main
spillway in its damaged state, prior to the initial recovery efforts. Its utility in passing
high inflows would have been temporary in nature, due to its continually failing state.
Similarly, the emergency spillway area would have remained in an eroded state, subject
to additional erosive forces with any subsequent future use. As evidenced by the
mandatory evacuation of the project area, the possibility of full failure of either project
feature presents an unacceptable risk to public safety. Due to serious public safety
concerns associated with failure of the project spillways and the high hazard potential of
Oroville Dam, the No-Action Alternative does not merit further consideration in this
analysis.
5.0 STATUTORY COMPLIANCE AND CONSULTATION
California DWR and the Commission have pursued informal and formal
consultation with federal resource agencies, state resource agencies, and applicable tribes
since the February 7, 2017 failure of the main spillway. The Commission has delegated
some of its responsibilities to California DWR for day-to-day matters, but it remains
ultimately responsible to ensure that its actions comply with the federal statutes discussed
below.
On March 2, 2017, California DWR established a work group to discuss
environmental issues related to the spillway failure. This work group included the
26
Commission, Army Corps, California State Water Resources Control Board (California
SWRCB), Central Valley Regional Water Quality Control Board (Regional Water
Board), National Marine Fisheries Service (NMFS), U.S. Fish and Wildlife Service
(FWS), California DFW, and the Federal Emergency Management Agency (FEMA). On
May 8, 2017, California DWR established an additional work group to discuss cultural
resource issues. This work group included the Commission, California State Historic
Preservation Officer (California SHPO), and FEMA.
By letter dated March 31, 2017, the Commission designated California DWR as its
non-federal representative for informal consultation with the FWS and NMFS pursuant to
section 7 of the Endangered Species Act (ESA). In the same letter, the Commission also
designated California DWR as its non-federal representative for informal consultation
with the California SHPO to implement section 106 of the National Historic Preservation
Act (NHPA).
The applicable statutes and respective consultations are discussed below.
Section 10 of the Rivers and Harbors Act & Section 404 of the Clean Water Act
Permits from the Army Corps are required under section 10 of the Rivers and
Harbors Act of 1899 for structures or work in or affecting navigable waters of the United
States and under section 404 of the Clean Water Act (CWA) for the discharge of dredged
or fill material in waters of the United States. California DWR obtained multiple permits
under Regional General Permit 8 (RGP 8), created for emergency actions that would
trigger these statutes,18 to support the response and recovery work associated with the
Oroville spillway failure. By letter dated February 24, 2017, the Army Corps issued an
RGP 8 for dredging work near the main and emergency spillway discharge points to the
Thermalito Diversion Pool. 19 By letter dated March 28, 2017, the Army Corps issued an
RGP 8 for discharge of fill material and placement of four culverts associated with
expansion of Burma Road.28 This permit was subsequently amended on June 1, 2017, to
include the temporary discharge of fill within Lake Oroville. The February 24, 2017
RGP 8 was amended on June 7, 2017, to include additional dredging work in the
Thermalito Diversion Pool, including the excavation of 1,720,000 cubic yards of
sediment. The Army Corps issued an additional RGP 8 for road improvements at the
lakeside spillway and construction on July 25, 2017. 21 This permit was later followed by
18 http://www.spk.usace.army.mil/Portals/12/documents/regulatory/gp/RGP-
08/RGP-8-EmergencyActions0929 2015.pdf.
19 RGP 8 Permit No. SPK-2017-00153.
RGP 8 Permit No. SPK-2017-00264.
21 RGP 8 Permit No. SPK-2017-00444.
27
a section 404-Nationwide Permit 33 for continued improvements and construction at that
location.
Section 401 of the Clean Water Act
Under section 401 the CWA, an applicant for a federal license or permit must
obtain a Water Quality Certification (401 certification) for any proposed activity that may
result in a new discharge into navigable waters. The 401 certification is a verification by
the state that a proposed project would not violate water quality standards. As discussed
above, California DWR obtained multiple RGP 8 authorizations from the Army Corps for
emergency activities at the site. By letter dated December 15, 2014, the California
SWRCB issued a broad 401 certification for the RGP 8 program.22 Among the
conditions of the RGP 8 permits, all permittees are required to implement measures for
spill prevention and response, erosion control and runoff, construction debris
management, and revegetation.
California DWR also obtained several permits from the Regional Water Board for
specific response and recovery actions in the Sacramento District of the Army Corps,
which includes the project area. Specifically, California DWR obtained section 401
certifications from the Regional Water Board for activities associated with: in-water
debris removal,' modifications to Burma Road along the north side of the Thermalito
Diversion Pool,' spillway road improvement and construction on the lakeside of Lake
Oroville,25 and continued lakeside spillway road improvements.26 Under the Regional
Water Board's certifications, California DWR is required to monitor turbidity, dissolved
oxygen, and pH in the Thermalito Diversion Pool and Lake Oroville. Commission staff
consider the response and recovery activities resulting in a material discharge (primarily
through dredging and erosion) to be covered under the RGP 8 permits and the section 401
certifications from the Regional Water Board.
22 http://www.spk.usace.army.mil/Portals/12/documents/regulatoiy/gp/RGP-
08/WQC-CA-WQCB-%2017-DEC-2014 Part{)/02016/020.pdf
23 Application at 59 (Section 7.7.4 In-Water Debris Removal) (citing authorization
VVDID#5A04CR00265).
24 Id. at 57-58 (Section 7.7.2 Access Roads, Work Pads, Staging Areas and Spoil
Sites) (citing authorization WDID# 5A04CR00266)
25 Id. (citing authorization WDID#5A04CR00269a).
26 Id.
(citing authorization WQC 5A04CR00278).
28
The National Historic Preservation Act
Under section 106 of the NHPA,27 and its implementing regulations,28 federal
agencies must take into account the effect of any proposed undertaking on properties
listed or eligible for listing in the National Register of Historic Places (NRHP) and must
afford the Advisory Council on Historic Preservation (Advisory Council) a reasonable
opportunity to comment on the undertaking.
California DWR's initial consultation with the California State Historic
Preservation Officer (California SHPO) began with the Army Corps' RGP 8 process for
the aforementioned dredge and fill work. By letter dated March 31, 2017, the
Commission designated California DWR as the Commission's non-federal representative
for consultation with the California SHPO. California DWR initiated consultation with
the California SHPO by a hand-delivered letter on April 24, 2017. California DWR
consulted with the SHPO on multiple proposals including relocation of one project
transmission line and one non-project transmission line, fortification of an existing
cultural site affected by construction activities, expansion of the emergency spillway, and
rebuilding of the main spillway.
Consultations with the California SHPO were originally conducted under the
Advisory Council's emergency provisions at 36 C.F.R. § 800.12(b)(2), which require the
California SHPO to respond within a 7-day period. The California SHPO advised
California DWR that the emergency process is time-limited and would apply only to
actions implemented prior to May 31, 2017.29
The Commission requested a 30-day extension of the expedited review period
(until June 30, 2017) from the Advisory Council to allow time for Commission staff to
develop a two-party Programmatic Agreement (PA) with the California SHPO. The PA
addresses and formalizes a mutually agreeable expedited process for cultural resource
reviews of California DWR's activities while conducting the long-term stabilization and
repair efforts (undertaking). The final PA was executed on July 5, 2017, with the
Commission and California SHPO as signatories, FEMA as an invited signatory, and
California DWR, California Office of Emergency Services, and the Enterprise Rancheria
Estom Yumeka Maidu Tribe as concurring parties. The PA was amended on September
25 and October 19, 2017.
27 54 U.S.C. § 300101 et seq. (2012).
28 36 C.F.R. pt. 800 (2018).
29 Application at 128; see 18 C.F.R. § 800.12(d) (2018) (limiting the emergency
procedures to undertakings that will be implemented within 30 days after the disaster or
emergency has been formally declared).
29
For activities after May 31, 2017, all consultations about the effects of the
undertaking on historic properties were and are considered pursuant to the PA's outline
of roles and responsibilities for the Commission, the California SHPO, FEMA, and
California DWR. California DWR has hosted regular teleconferences to update the
agencies on California DWR's stabilization and repair efforts, both under the emergency
provision and the PA, beginning on May 1, 2017, and continuing until the undertaking is
complete. California DWR's proposed modifications to the Area of Potential Effect
(APE), as well as recommendations for determinations of eligibility and findings of effect
for activities conducted as part of the undertaking, were filed with the Commission.
Consultations have resulted in several letters from the Commission concurring with the
California DWR's determinations and findings.30 Under the PA, California DWR has
also completed quarterly reports, documenting any effects to cultural resources. Further
information related to NHPA compliance is discussed in section 6.9-Cultural and
Historic Resources.
On February 8, 2017, California DWR, with assistance from the California
Department of Parks and Recreation, immediately contacted four federally recognized
tribes in the Oroville vicinity. These tribes included the Berry Creek Rancheria of Maidu
Indians, the Estom Yumeka Maidu Tribe of the Enterprise Rancheria, the Mechoopda
Indian Tribe of Chico Rancheria, and the Mooretown Rancheria of Maidu Indians.
Additionally, Greenville Rancheria, another federally recognized tribe, and two non-
recognized tribes (Konkow Maidu and Tsi-Akim Maidu) were contacted following a
response from the California Native American Heritage Commission (NAHC) on March
29, 2017.
Enterprise Rancheria has participated in tribal cultural resource identification and
monitoring of response and recovery activities since mid-February 2017. Daily tribal
monitoring by Enterprise Rancheria members began on February 27, 2017. California
DWR initially met with the Enterprise Tribal Council on March 7, 2017, and with tribal
elders in the field on March 17, 2017. Consultation with Enterprise includes their Tribal
Historic Preservation Officer (THPO), and is on-going. The last formal meeting with the
Tribal Council was held on August 28, 2017. The Enterprise Rancheria were invited as a
concurring party to the aforementioned July 5, 2017 PA for management of cultural
resources affected by the response and recovery efforts, but did not provide a response.
3° The Commission issued letters on August 29, 2017, October 23, 2017,
November 7, 2017, December 1, 2017, December 7, 2017, December 14, 2017, February
5, 2018, April 6, 2018, June 13, 2018, June 14, 2018, August 8, 2018, August 28, 2018,
and October 4, 2018.
30
The Endangered Species Act & the Bald and Golden Eagle Protection Act
Section 7 of the Endangered Species Act (ESA) requires federal agencies to ensure
their actions are not likely to jeopardize the continued existence of federally listed
threatened or endangered species, or result in the destruction or adverse modification of
the critical habitat of such species. Several federally listed species are known to use or
could potentially be affected by the Feather River Project, including: central valley spring-
run Chinook salmon; central valley steelhead; southern distinct population segment
(DPS)North American green sturgeon; delta smelt; Butte County meadowfoam; hairy
orcutt grass; Hartweg's golden sunburst; Greene's tectoria; Hoover's spurge; slender
orcut grass; Layne's ragwort; giant garter snake; California red-legged frog; Sierra
Nevada yellow-legged frog; vernal pool fairy shrimp; Conservancy fairy shrimp; vernal
pool tadpole shrimp; and valley elderberry longhorn beetle.
On February 24, 2017, NMFS sent a letter to the Commission providing twelve
recommendations to minimize the effects on federally listed fish species, and their critical
habitat below fish barrier dam from dredging and flow fluctuations during the initial
response. These fish species included central valley spring-run Chinook salmon, central
valley steelhead, and southern distinct population segment (DPS) North American green
sturgeon. The letter also recommended that the Commission initiate formal consultation
with NMFS as soon as the emergency had stabilized. On February 27, 2017, the
Commission discussed the recommendations with NMFS and California DWR, which
included ramping rate recommendations, minimum flow maintenance, dredging
guidance, water quality maintenance at the Feather River Fish Hatchery, fish monitoring
and salvage, water quality monitoring, water release recommendations, turbidity
minimization measures, agency coordination, and data reporting. California DWR
implemented the conditions to the extent possible, but was limited in its ability to meet
NMFS' recommendations for ramping rate reductions, due to its conflicting efforts to
maintain and observe the structural integrity of the remaining portion of the main
spillway.
By letter dated March 31, 2017, the Commission designated California DWR as its
non-federal representative to conduct informal consultation with NMFS and the FWS
pursuant to section 7 of the ESA. Since that time, California DWR and the Commission
have regularly consulted on planned flow changes, monitoring, and construction
activities, primarily through regular conference calls. California DWR's consultation
with these agencies has been ongoing.
The only species pertinent to the spillway failure and the FWS authority is the
valley elderberry longhorn beetle which is listed as threatened. California DWR has
consulted informally with the FWS on the relocation of elderberry bushes affected by
construction activities. The FWS has also been a participant in regular conference calls
with California DWR, the Commission, and the resource agencies. By letter dated
31
December 14, 2017, the Commission confirmed that it would be entering into formal
consultation with the FWS under the emergency provisions of the ESA, including the
preparation and submission of a biological assessment for the effects of the response and
recovery efforts.31 California DWR has also consulted informally with the FWS about
the potential for construction activities to disturb the nest of a bald eagle, which is
protected under the Bald and Golden Eagle Protection Act.
The Commission, California DWR, NMFS, and the FWS have been consulting
informally on the development of draft biological evaluations for aquatic and terrestrial
resources. Both NMFS and FWS have provided verbal comments on the draft biological
evaluations, followed by additional revision by the California DWR. By letter dated
June 29, 2018, California DWR filed a biological evaluation with the Commission on the
effects to the fish species under the jurisdiction of NMFS. By letter dated July 5, 2018,
the Commission adopted the biological evaluation as its biological assessment and sent it
NMFS, and requested the initiation of formal emergency consultation. Similarly,
California DWR filed a biological evaluation with the Commission on July 16, 2018 and
supplemented on August 1, 2018, on the effects of terrestrial resources under the
jurisdiction of FWS. By letter dated August, 14, 2018, the Commission issued a
biological assessment and requested the initiation of formal emergency consultation with
the FWS. By letter dated September 10, 2018, the FWS concurred with the
Commission's determination that the emergency actions related to the spillway failure
may have affected, but did not likely adversely affect the federally-listed valley
elderberry longhorn beetle. The FWS did not require any additional conditions to its
determination.
6.0 ENVIRONMENTAL ANALYSIS
6.1. Scope of the Analysis
The geographic scope of this analysis includes the entire project area including
Lake Oroville, the Thermalito Diversion Pool, Thermalito Forebay, Thermalito Afterbay,
Fish Barrier Dam Pool, Feather River Fish Hatchery, OWA, and the Feather River from
the Fish Barrier Dam to its confluence with the Sacramento River near Verona, CA. As
discussed above, the temporal scope of this environmental assessment begins with the
response efforts that occurred from February 7, 2017, through May 19, 2017, and
continues through the ensuing recovery period from May 20, 2017 to completion of main
31 The Commission had been previously consulting informally with the FWS on a
proposal to utilize the OWA as a borrow area for construction activities. The
December 14, 2017 letter was in response to the FWS' December 12, 2017 letter
providing conservation recommendations for use of the OWA. However, California
DWR has since retracted its proposal to utilize the OWA as a borrow area.
32
and emergency spillway construction activities anticipated on January 26, 2019. The
resources potentially affected by this proposal include geology and soils, water quantity
and flow, water quality, fisheries and aquatic resources, terrestrial resources, threatened
and endangered species, cultural and historic resources, recreation, land use and aesthetic
resources, air quality, transportation, and noise. Because of the emergency nature of the
response actions and the 2017 recovery actions, this EA looks retroactively at
environmental effects of activities that preceded California DWR's filing on
January 29, 2018, and looks prospectively at potential environmental effects of activities
to occur after the date of the filing.
6.2 General Description of the Project Area
The project is located on the Feather River in Butte County, California, in the
foothills of the Sierra Nevada and Sacramento Valley. Oroville Dam is located 5 miles
east of the city of Oroville, CA, and about 65 miles north of Sacramento, CA. The
Oroville facilities were developed as part of the State Water Project, a water storage and
delivery system of reservoirs, aqueducts, power plants, and pumping plants. The main
purpose of the State Water Project is to store and distribute water to supplement the needs
of urban and agricultural water users in northern California, the San Francisco Bay Area,
the San Joaquin Valley, and southern California. The facilities are also operated for flood
management, power generation, water quality improvement in the Sacramento-San
Joaquin Delta, recreation, and fish and wildlife enhancement.
The proposed work area associated with the proposed spillway repairs is heavily
disturbed. Following the failure of the main spillway beginning February 7, 2017, the
area near the lower portion of the spillway experienced major erosion, with the majority
of an estimated 2.2 million cubic yards of sediment deposited in the Thermalito Diversion
Pool. Similarly, the area immediately downstream of the emergency spillway
experienced significant erosion following its first-ever use on February 11, 2007. The
immediate area below the spillway was also cleared of vegetation immediately before
activation of the emergency spillway to avoid trees and vegetation from being washed
into the Thermalito Diversion Pool and disrupting the operation of the downstream
project works. Finally, during the initial response activities California DWR has
stockpiled a considerable amount of sediment from dredging operations near the
proposed work area, has graded hillsides adjacent to the main spillway, and has
constructed various access and haul routes. Thus, the proposed work area has
experienced numerous recent disturbances resulting from the=initial response to the
spillway failure.
33
6.3 Geology and Soils
6.3.1 Affected Environment
The project is located in the western foothills of the Sierra Nevada mountain
range, at the eastern edge of California's Central Valley. Bedrock within the area is
composed of folded, metamorphosed sedimentary and igneous rocks, overlain by strata of
volcanic and sedimentary origin. Oroville Dam is located within an area of bedrock
dominated by metamorphic amphibolite. Within the approximately five miles of the
Feather River below the dam, the bedrock transitions to scattered sedimentary and
volcanic deposits.
Soils within the project area are comprised of weathered igneous and sedimentary
bedrock found near the project. Below Oroville Dam, soils found on level land are
comprised of alluvium and mining debris, and are dominated by fine sandy loam, loamy
sand, and loam to silty loam. Less common soil types include those containing clay, silt,
and gravel. Soil depth ranges from shallow to very deep, but are generally moderately
deep to very deep. Sediment from historic gold mining activities, either as tailings or
fine-grained deposits from upstream hydraulic mining, known as slickens, comprise
approximately 35 percent of the riverbank below Oroville Dam.
During its recovery activities, California DWR's contractor analyzed samples of
rock from the area of the main spillway for characteristics such as pH and constituents
including heavy metals and other substances harmful to environmental resources, if
mobilized. The contractor's analysis indicated that native rock located at the downstream
end of the main spillway contains copper pyrite, which includes copper, iron, and sulfur.
6.3.2 Environmental Effects
Following initial use of the emergency spillway, California DWR graded,
deposited rip-rap, and applied approximately 107,000 cubic yards of shotcrete to the
emergency spillway apron to reduce the amount of soil and rock lost if the emergency
spillway needed to be used again. During the response activities, California DWR also
constructed a large number of unpaved access roads and staging areas across the hillside
below the dam. At the main spillway, California DWR constructed crane pads and
removed bedrock with explosives to eliminate unstable slopes at the site of the spillway
failure. Furthermore, California DWR dredged 1.4 million cubic yards of eroded
material from the ThermaIito Diversion Pool during the response phase, which it
deposited in three spoil piles within the project area. One pile is located northwest of the
Thermalito Diversion Dam, one is located below the emergency spillway, and one is
located on the right bank of the Thermalito Diversion Pool below the main darn.
California DWR estimates that the placement of the crane pads and spoil piles affected
approximately 42 acres of land.
34
As described previously, during the emergency response phase, California DWR
initiated rapid down-ramping rates of the main spillway to facilitate inspections and
emergency repairs, while reducing additional erosion of the spillway foundation. These
rapid drops in spillway flows, though attenuated within the river channel, were also
experienced further down the Feather River, below Oroville Dam. The abnormally high
flows, followed by rapid decreases in river elevation below the project, had the potential
to produce sloughing, in which high water saturates the river bank which then migrates
down into the river under its own weight once the river falls and no longer supports the
saturated soils. The likelihood of such sloughing occurring would be dependent upon the
proximity to Oroville Dam, topography, previous disturbance, and soil type. Soil water
content and pressure are also important factors in bank stability, which can reduce shear
strength, increase the weight of bank material, provide a destabilizing force through water
present in tension cracks, and provide additional seepage forces (Rinaldi and Darby
2008). Rinaldi et al. (2004) also found that bank failures occur primarily during down-
ramping events.
Following the aforementioned flow reductions during the response phase,
Commission staff were informed of areas in the Feather River where portions of the
streambank sloughed off into the Feather River (Gallagher et al. 2017). The
Commission's review of the available facts and flow data indicates that the sharp flow
reductions were likely a main factor in the reported bank sloughing. However, other
factors likely contributed to the observed streambank failures, including the existence or
manipulation of riparian vegetation, the natural soil moisture content from precipitation,
or preceding erosion from high flows during the extremely wet hydrologic year.
Commission staff also reviewed satellite images of the entirety of the Feather River
below the Fish Barrier Dam from before (August 22, 2016) and after (May 18, 2017) the
spillway failure (Google Earth 2018). Though not intended to be a robust final analysis,
staff's review does not indicate that bank sloughing was widespread, and was likely
localized in nature. Nonetheless, any potential streambank sloughing theoretically would
be visually obscured from high flows on May 18, 2018, when the latest satellite photo is
available. Consequently, the locations of the sloughing or the volume and area of soil
affected is unknown, because of the lack of reliable pre and post-event information.
Following the termination of its emergency response actions and during its initial
recovery operations, California DWR added an additional 600,000 cubic yards of dredge
material to the spoil piles. California DWR intends to process the spoils and use suitable
material as aggregate for its concrete batch plants. However, California DWR expects
that it would require an additional 380,000 cubic yards of aggregate, which it plans to
obtain from a borrow area to the left of the main spillway, and approximately 1,000 feet
upstream from where the spillway discharges into the Feather River. This borrow area
would cover 7.1 acres, with a depth of 80 feet. California DWR also states that it would
need approximately 25,000 cubic yards of pervious fill for reconstruction of the main
35
spillway. This material would be imported from a local commercial supplier, located
approximately 17 road miles northeast of the dam site.
In conjunction with other recovery activities, California DWR's proposal to
replace the 13.8-kV Hyatt-Thermalito Transmission Line and communication cable
would directly, though temporarily, impact a narrow trench, approximately 3.8 miles
long. Like the other construction activities related to the proposal, this disturbance would
displace soils and make them more vulnerable to wind and water erosion. The proximity
of the transmission line to the Thermalito Diversion Pool also creates the potential for
runoff, possible adversely affecting water quality within the river during and following
construction.
Through construction of temporary roads, excavation within the project area,
deposition of dredged spoils, and work conducted on the emergency spillway, California
DWR exposed and disturbed several hundred acres of soil and rock. As such, the
probability of this material being eroded through wind and rain action increases. Erosion
and sedimentation of exposed soils also impacted water quality (see also section 6.5-
Water Quality). The risk of erosion would have been greater during the response
activities, when rainfall was more likely, and the emergency dictated that installation of
erosion control measures take a lower priority. However, where possible, throughout its
response and recovery activities, California DWR indicates it has graded spoil piles and
excavations to reduce the possibility of erosion. California DWR has also protected
disturbed soils by applying seed mixtures, gravel, or pavement. California DWR states
that following construction, it will conduct additional grading, seeding, or planting that
will be described in its proposed area-wide Restoration Plan.
California DWR's actions had a significant, permanent, and adverse effect on
geology and soil resources at the project. Through California DWR's actions, hundreds
of thousands of cubic yards of material were extracted from areas near the Oroville Dam
during the response activities, and California DWR is proposing to use some of that
material for spillway construction. These actions permanently changed the topography in
these locations. Furthermore, despite its control efforts, California DWR's actions
disturbed and exposed many acres of soils, likely leading to the loss of unquantified
amounts of soils and rock through erosion from the project site. Additionally, its rapid
down-ramping events likely contributed to sloughing and erosion of riverbanks well
below the project.
In conclusion, much of the impact on geology and soils from California DWR's
actions were or are unavoidable, particularly during the response activities. However,
California DWR's measures to reduce erosion, along with staff's recommended
measures, will help mitigate the adverse effects to geological and soil resources.
36
6.3.3 Staff Recommendations
California DWR proposed an area-wide Restoration Plan but did not identify the
particular aspects of its plan. Commission staff recommends California DWR be
required to prepare a plan that describes California DWR's specific rehabilitation efforts
to restore disturbed areas following construction, including the borrow area and spoil
piles. The plan should also include a protocol for monitoring and reporting progress on
the restoration activities to the Commission.
As a result of the ambiguous nature of downstream sloughing possibly caused by
California DWR's response activities, Commission staff recommends California DWR be
required to analyze the Feather River conditions below the Oroville Dam. The analysis
should include a survey of the river banks and channel to identify areas of mass wasting
resulting from the flow reductions at the main spillway and associated deposition of
sediment within the waterway. The analysis should compare pre and post-event
conditions, to the extent possible and should document any impaired areas that were the
result of the sharp flow reductions. California DWR should be required to provide a plan
for directly or indirectly mitigating the impaired locations.
6.4 Water Quantity and Flow
6.4.1 Affected Environment
The project utilizes the Feather River Basin to generate electricity and to supply
water, with a drainage area of 3,624 square miles. The Feather River Basin has mild, dry
summers and heavy winter precipitation, with mean annual precipitation ranging from
11 inches in the driest years in the driest areas to 90 inches in mountainous regions near
Mount Lassen. The majority of the precipitation in the basin headwaters is in the form of
snow during November through March, with much of the snowpack melting by mid-
April in the mid-range elevations (3,000-5,000 feet). Accordingly, California DWR
manages project storage and releases, based on the annual hydrologic patterns typical of
the Feather River Basin.
Flows below Oroville Dam are managed through a combination of releases from
Hyatt Power Plant, river valve releases at Oroville Dam, spillway flows, and releases
from the Thermalito Diversion and Thermalito Afterbay. The Hyatt Power Plant has a
maximum release capability of 16,950 cfs, with release through the power plant typically
peaking during the spring.and summer to meet water and energy demands. The river
valve (low level outlet works), located adjacent to the Hyatt Power plant has a release
capacity of 5,400 cfs (4,000 cfs at the time of the main spillway failure), and was out of
service between 2009 and 2017, due to safety concerns with its operation. The OroviIIe
main spillway has a maximum flow capacity of 250,000 cfs, and is generally used during
37
the wet winter months to ensure adequate storage space in Lake Oroville for flood control
purposes.
During normal and wet water years, Lake Oroville is filled to its maximum annual
elevation of 901 feet msl in June, and is then lowered to meet downstream requirements,
until reaching its lowest annual level in December or January. During dry years, the
reservoir may be drawn down further, and not reach desired levels in the spring. In
addition, the Army Corps requires that the lake be operated to maintain up to 750,000
acre-feet of storage space to capture inflows for flood control. Since the project began
operation in 1967, the minimum elevation at Lake Oroville occurred on 2014, when the
reservoir was at 645.11 feet msl, corresponding to a reservoir content of 882,395 acre-
feet. This was at the end of one of the most severe droughts in recorded California
history. The maximum reservoir elevation occurred on February 12, 2017, when the
reservoir was at 902.59 feet msl, corresponding to a reservoir content of 3,578,686 acre-
feet.
Rates of release to the Feather River are also constrained by non-license ramping
rate requirements. Under a separate 1983 agreement with the California Department of
Fish and Came32 and in 2002 and 2004 Biological Opinions by NMFS for the State
Water Project, California DWR is required to provide minimum flows and to implement
prescribed ramping rates in the high and low flow channels. Specifically, under the 1983
agreement, California DWR is required to limit 24-hour down-ramping rates in the
Feather River to: 200 cfs if flows are less than 2,500 cfs; 500 cfs if flows are between
2,500 and 3,500 cfs; 1,000 cfs if flows are between 3,500 and 6,500 cfs; and 2,000 cfs if
flows are greater than 6,500 cfs. Under the biological opinions, California DWR is
required to limit 24-hour down-ramping rates in the Feather River to: 20033 cfs if flows
are between 600 and 2,500 cfs; 500 cfs if flows are between 2,501 and 3,500 cfs; 1,000
cfs if flows are between 3,501 and 5,000 cfs; and 2,000 cfs if flows are greater than 6,500
in the low flow channel. Similarly, flow increases are limited to 5,000 cfs per hour;
regardless of flow during the previous hour. Finally, license Articles 29 and 53 require a
year-round minimum flow of 600 cfs in the low flow reach and between 1,000 and 1,700
cfs in the high flow channel, depending on the season and water year type.
The downstream Thermalito Diversion Pool and Thermalito Forebay are
hydraulically connected, and are operated in tandem. The two impoundments experience
minor daily fluctuations, but may cycle down 2-4 feet during the course of a week, and
then refill by the weekend. The Thermalito Afterbay is operated to meet multiple
32 Now the California Department of Fish and Wildlife.
33 NMFS states this value is 200 cfs while California DWR maintains that this
value is 300 cfs. The Commission's Final Environmental Impact Statement (FERC
2007) assumes it is the NMFS value of 200 cfs.
38
requirements, including regulating inflow from pump-storage hydropower operations,
providing water for withdrawal for irrigation needs, and providing minimum flows in the
Feather River. As a result, the Thermalito Forebay typically fluctuates between 2-6 feet
during a week, but may fluctuate between 9 and 11 feet, due to seasonal operations.
The Feather River downstream of Oroville Dam includes a low-flow bypass
section below the Thermalito Diversion Pool and Fish Barrier Dam. It also includes a
high-flow channel below the Thermalito Afterbay, where it meets the low-flow channel.
Mean flow releases from the Thermalito Afterbay fluctuate throughout the year, based on
upstream hydrologic conditions, environmental needs, and water demand. Typical
average flows are lowest in October at 1,942 cfs and peak in March, with an average flow
of 5,499 cfs. Mean flow releases in below the fish barrier dam are typically the lowest in
September with an average flow of 522 cfs, and peak in February at an average of
2,155 cfs.
6.4.2 Environmental Effects
During the initial response period, California DWR lost its ability to make reliable
flood flow releases from the main spillway. While the main spillway was still partially
functional, low flow releases through the spillway were avoided to prevent water from
undercutting the main spillway. Thus, elevated spillway releases were made to propel
water beyond the end of the damaged main spillway and to avoid further erosion of the
material underlying the main spillway.34 In addition, high spillway releases in excess of
100,000 cfs were also avoided to prevent further erosion of the main spillway and the
adjacent hillside, thus limiting main spillway releases to a preferred range of flows. The
inability to release a full range of flows was further exacerbated by the sediment
deposited below the main spillway causing water to back up to the Hyatt Power Plant.
This rendered the powerhouse inoperable, thus preventing it from releasing water from
Lake Oroville through generation. Consequently, California DWR's ability to release a
full range of flows was temporarily impaired until Hyatt Power Plant operations were
restored on March 3, 2017, and to a greater degree when the main spillway was restored
to a functional state, but not fully repaired, on November 1, 2017.
34 Review of flow records for the response period indicates that the smallest sharp
reduction was from 25,000 cfs to zero, which occurred on May 19, 2017 (California Data
Exchange Center, httD://cdec.water.ca.govldynamicapp/QueryF?s=ORO, accessed June
21, 2018).
39
California DWR's use of the main spillway on an intermittent basis during the
response phase resulted in large atypical flow fluctuations in the Feather River. Due to
the necessity of passing large inflows from Lake Oroville and the constraints of an
eroding main spillway, California DWR implemented large main spillway releases, .
followed by abrupt reductions. While heightened spillway releases are a normal part of
project operations during the winter months, the abrupt cessation of flows following these
releases is atypical. The modified spillway flows implemented by California DWR
exceeded the above ramping rates, by reducing spillway releases instantaneously from as
much as 60,000 cfs to zero. These sharp main spillway releases caused short-term
reductions on four occasions during the response phase in the low-flow section of the
Feather River, and to a slightly lesser extent the high-flow section of the river (Figure 7).
In spite of these large flow fluctuations, California DWR managed flow releases and
preserved storage in the Thermalito Diversion Pool to meet the license-required
minimum flow of 600 cfs in the low-flow channel during the response period.
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during the 2017 response period (source: California DWR 2018b).
40
During the ensuing recovery phase, California DWR has managed Lake Oroville
storage levels to avoid use of the spillway, and would continue to do so to facilitate
reconstruction efforts during its recovery efforts. During 2017, California DWR
managed Lake Oroville levels to avoid additional use of the spillways, to the extent
possible, while also maintaining an adequate flood storage buffer. California DWR
would thereafter reduce Lake Oroville levels to avoid water levels coming into contact
with the spillway gates and to provide an adequate buffer for inflows in Lake Oroville
while spillway reconstruction efforts are in progress. In order to meet these objectives,
California DWR managed Lake Oroville levels to reach 700 feet msl by November 1,
2017. These levels are below storage levels in the reservoir that would otherwise have
been maintained during the 2016-2017 record-high year of precipitation. In addition,
California DWR would maintain depressed reservoir levels during the 2017-2018 water
year to avoid using the main spillway (Figure 8, California DWR 2018c).
2017-2018 Winter Operations Plan
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41
According to its April 17, 2018 flood operations plan, California DWR would
continue to proactively manage Lake Oroville storage levels for the 2017-2018 flood
control season to safely pass flows. However, due to the partial reconstruction of the
main spillway, California DWR would manage Lake Oroville levels so that they do not
exceed the interim main spillway release capacity of 100,000 cfs and also meet existing
flood requirements. Specifically, California DWR would manage lake levels by releasing
flows through the Hyatt Power Plant to maintain lake levels below 725 feet in November
and December 2017, 750 feet during January 2018, 775 feet in February 2018, 800 feet in
March 2018, and 830 feet in April through June 2018. If forecasts indicate that lake
elevation would increase beyond the spillway floor elevation of 813.6 feet, then
California DWR would assess whether use of the main spillway is necessary. Use of the
spillway during 2017 and 2018 should not result in any abnormal flow releases or
curtailments similar to the sharp flow reductions that occurred during spring 2017.
However, the 830-foot maximum storage limit will result in slightly further depressed
reservoir elevations than would have been present without the restriction, and are
typically of below-normal water years (such as the current 2017-2018 water year).
In summary, California DWR's proposal resulted in short-term irregular flow
releases to the Feather River during the February to May 2017 response period, but
would return to normal operations during the entirety of the May 2017 to January 2019
recovery period. California DWR's proposal will also result in short-term reductions to
Lake Oroville during the 2017-2018 recovery period to facilitate response and recovery
actions. However, Lake Oroville water levels will return to normal seasonal cycles
thereafter.
6.4.3 Staff Recommendations
California DWR has managed, and would continue to manage water levels in Lake
Oroville and the Feather River to facilitate response and recovery efforts. These effects
to water quantity are temporary in nature and therefore, Commission staff do not
recommend any mitigative actions.
6.5 Water Quality
6.5.1 Affected Environment
Water quality in the project area is generally good, and is influenced by water
quality in the upstream tributaries. Consequently, the water quality in the downstream
impoundments and Feather River is largely determined by the water quality released from
Oroville Dam. Nonetheless, the lower Feather River, downstream of Oroville Dam to its
confluence with the Sacramento River, is listed on the U.S. Environmental Protection
Agency's approved list of waters as being impaired by mercury, certain pesticides, and
toxicity of unknown origin. A total maximum daily load for the pesticide diazinon was
42
also established for this reach in 2004. The Regional Water Board's Basin Plan also has
several water quality objectives.for the Oroville Facilities, including temperature,
turbidity, dissolved oxygen, pH, settleable solids, chemical constituents, sediment,
conductivity, and fecal coliform bacteria. Among these objectives, California DWR and
California DFW entered into a 1983 agreement to maintain suitable water temperatures in
the Feather River below the Thermalito Diversion Dam and Afterbay for fall-run
Chinook salmon during the fall, and for shad, striped bass, and other warm water species
from May through August. This generally results in mean water temperatures between
53 and 65 degrees F (11.7. to 18.3 C) in the Feather River from June to October. Water
temperatures drop however, to around 45 degrees F (7.2 C) during cooler winter months.
Water temperature in the Thermalito Diversion Pool is generally a function of
flow releases from Oroville Dam and Hyatt Power Plant. Water temperatures in the
Diversion Pool are generally cool and undergo very little stratification, because of nearly
constant flow releases from Oroville Dam and Hyatt Power Plant. Water temperature in
the downstream Thermalito Afterbay is generally warmer by a few degrees and increases
in the spring and summer, reaching about 76 degrees F in the northern part of the
Thermalito Afterbay during the warmer months.
Dissolved Oxygen (DO) concentrations and pH levels at the project generally
comply with water quality objectives of the Basin Plan, with the majority of exceedances
being observed at either the bottom of Lake Oroville or the Thermalito Afterbay.
Specifically, DO concentrations less than the Basin Plan's objectives generally occur in
Lake Oroville when the reservoir is stratified in the summer or in the Feather River when
decomposing salmon carcasses are present. pH levels also generally remain above (i.e.,
less acidic than) the Basin Plan objective of 6.5 at the project.
During normal operation, turbidity levels in the project area are also generally low,
due to the majority of sediments settling out in Lake Oroville before reaching the Feather
River and Thermalito Diversion Dam, Forebay, and Afterbay below Oroville Dam.
Studies conducted during relicensing of the project indicate that turbidity Ievels within
Lake Oroville are generally less than 10 nephelometric turbidity units (NTU), with levels
in the Thermalito Complex35 generally remaining below 8 NTU. Downstream of the
Thermalito Complex, turbidity levels generally increase, likely as a result of sediment
inputs from Feather River tributaries and high flow from storm events.
•
Metal concentrations in the project area are primarily a result of abandoned mining
practices and development of municipal and industrial land uses. Consequently,
monitoring activities have detected excessive levels of aluminum, arsenic, iron, mercury,
manganese, and lead; with Basin Plan exceedances in the Feather River increasing in
3s The Thermalito Diversion Dam, Forebay, and Afterbay are collectively referred
to as the Thermalito Complex
43
frequency downstream of the project boundary. Agricultural activities in the area have
also accounted for occasional elevated levels of pesticides in the project area. Monitoring
efforts at the projects however, have not routinely resulted in elevated levels of
conductivity and mineral concentrations, petroleum-based products, nutrients, or
pathogens.
6.5.2 Environmental Effects
California DWR's response and recovery actions have the potential to affect water
quality in the Feather River downstream of Oroville Dam, Thermalito Diversion Pool,
Thermalito Forebay, and Thermalito Afterbay. The primary activities that could affect
water quality include flow management, dredging, and construction activities. As a
condition of its permits for dredging activities during the initial response phase,
California DWR monitored turbidity, total suspended solids, settleable solids, dissolved
oxygen, water temperature, conductivity, and pH at 7 location in Lake Oroville and the
Thermalito Diversion Pool (Figure 9). As a condition of its permits for recovery actions,
California DWR developed a water quality sampling plan, which included a total of six
continuous monitoring stations in the diversion pool, power canal leading to the
Thermalito Forebay, fish barrier pool, and in Lake Oroville (Figure 10). Among the
parameters of the plan, California DWR would continuously monitor turbidity, DO, water
temperature, conductivity, and pH. Additional discrete monitoring would also occur for
water temperature, pH, dissolved oxygen, specific conductance, turbidity, total suspended
solids, and settleable solids. The following is a discussion of the results of this early
monitoring, and the anticipated effects to individual water quality parameters during the
remainder of the 2018 recovery phase.
Turbidity
Among the events that transpired during the response phase, the erosion in the area
of the main and emergency spillways had the most pronounced adverse effect on water
quality, depositing 2.2 million cubic yards of material into the Thermalito Diversion
Pool. Monitoring conducted under during the initial response phase indicates that
turbidity was very high during the initial erosion of the main spillway, with California
DWR reporting levels as high as 974 NTU in the Feather River shortly following the
initial main spillway failure. California DWR's continued use of the degraded main
spillway, in lieu of the inoperative power plant and river valve outlet, had severe short-
term adverse effects to turbidity levels in the Feather River and Thermalito Complex.
44
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litoring stations in the
Figure 9. Response-period water quality moi
Pool (source: DWR 2018b)
45
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Figure 10. Continuous recovery-period water quality monitoring locations (source:
California DWR 2018b)
46
Turbidity levels also increased temporarily with dredging activities in the
Thermalito Diversion Pool. Elevated turbidity levels from spillway erosion and dredging
were the highest in the Thermalito Diversion Pool near recovery activities, and dissipated •
downstream as sediments settled out in downstream impoundments, or diminished by
combining with less turbid tributaries further downstream. For example, elevated
turbidity levels were as high as 963 NTU in the Thermalito Diversion Pool between
February 27 and March 12, 2017 during dredging activities (Table 1). Much of the
sediment introduced into the Thermalito Diversion Pool was medium to large-sized
material that settled out in the Thermalito Diversion Pool, until later being removed by
dredging activities. However, the fine silt and clay-sized particles that were transported
downstream caused short-term high turbidity levels in the Feather River and likely settled
out in lower velocity areas, such as eddies, backwaters, and low-gradient areas near the
confluence with the Sacramento River. This sediment should remain in the lower
gradient areas until a subsequent high flow event mobilizes the material or is
mechanically removed from the river. No additional dredging is proposed after fall 2017,
and therefore should not result in elevated turbidity during the remainder of the recovery
phase.
Table 1. Results of turbidity moniting in the Thermalito Diversion Pool, condcuted
between February 14-August 18, 2017 (source: California DWR 2018b).
Reporting Bidwell Canyon WQH5• WQ#1 W0.42 WQti3 WQ#4 WQ86 WO,IP
Period •
Average Max Average Max Average Max Average Max Average Max Average Max Average 1 Max Average I Max
February 14-
February 26 20.7 NTU 37.8 NTU Va? ,i,,,: 38.6 NTU 584 NTU 36.8 NTU 48.6 NTU 36.2 NTU 49.1 NTU 39.3 NTU 614 NTU �2
February 27• 01,00-10,
i o F '' - :
1 tx, x �/
March 12" 18.1 NTU 38.4 NTU 136.6 NTU 963 NTU 62.5 NTU 269 NTU 67.3 NTU 135 NTU 55.9 NTU 114 NTU 40.8 NTU 81.5 NTU ,, ,0 ' w, '
March 13- ^' `t_55' <n; "
March26 169 NTU 349 NTU 29.7 NTU 125 NTU 342 NTU 131 NTU 37.8 NTU 117 NTU 44.9 NTU 217 NTU 37.4 NTU 152 NTU
a ` spa
March 27- arr itA r fir.
5h' ^r Mn eta -...'S ,
April 9 10.0 NTU 22A NTU 15.4 NTU 38.5 NTU 20.9 NTU 40.0 NTU 216 NTU 48.9 NTU 23.6 NTU 36.5 NTU 19.4 NTU 32.0 NTU N jDllOft►jCSg �i ldannhh
April 10- "0l5,_b7� ,
April 24 59 NTU 7.5 NYU 9.8 NTU 15.0 NTU 12.7 NTU 20.6 NTU 14.7 NTU 245 NTU 21.4 NTU 551 NTU 148 NTU 40.6 NTU LAW `T tz ' 't h
April 25- ' 2t a . s ;3 �,
� �
May 8 3.8 NTU 5.2 NTU 6.5 NTU 11.4 NTU 8.8 NTU 25.5 NTU 9.9 NTU 28.5 NTU 12.1 NTU 21.9 NTU 9.4 NTU 26.2 NTU
May 9-
May 21 5.8 NTU 12.1 NTU 6.1 NTU 19.3 NTU 5.8 NTU 14.1 NTU 6.9 NTU 19.6 NTU 8.2 NTU 23,3 NTU 7.5 NTU 32.8NTU "' ,. v
May 22-
Junes 5.4 NTU 12.1 NTU 6.1 NYU 6.7 NTU 5.7 NTU 17.6 NTU 6.0 NTU 9.7 NTU 15 NTU 23.1 NTU 4.6 NTU 7,4 NTU
June 6-
June 18 7.5 NTU 13.3 NTU 3.1 NTU 4.7 NTU 4.3 NTU 7.3 NIL! 5.1 NTU 12.5 NTU 8.1 NTU 15.6 NTU 3.8 NTU 4.6 NTU 4.0 NTU 4.5 NTU 4,3 NTU 6.0 NTU
June 19-
July 4 5.6NTU 14.5NTU 3.0NTU 6.6 NTU 4,6NTU 10.5NTU 4.6 NTU 6.9NTU 6.3NTU 18.6 NTU 3.6 NTU 5.6NTU 3.9 NTU 5.6NTU 4.3 An 6.4 NTU
July 5
July 18 7.6 NTU 18.3 NTU 2.5 NTU 3.9 NTU 5.8 NTU 11.5 NTU 5.0 NTU 9.7 NTU 7.2 NTU 20.1 NTU 3.3 NTU 6.2 NTU 3.5 NTU 6.6 NTU 3.8 NTU 4.7 NIL!
July 19-
July30 8.1NTU 17.3NTU 3.1NTU 4.6 NTU 5.7 NTU 9.3 NTU 5.4 NTU 15.2 NTU 8.7NTU 23.7NTU 4.4 NIL! 8.5 NTU 4.4 NTU 6.5 NTU 4.7NTU 5.8 NTU
July 31-
August 18 6.2 NTU 18.7 NTU 6.5NTU 22.3 NTU 5.3 NTU 9.6NTU 4.9 NTU 8.6NTU 7.1NTU 16.6 NTU 4,1 NTU 6.0 NYU_4.4 NW 7,9 NTU 4.8 NTU 6.9NTU
WQ#5 Discrete sampling initiated on March 1,2017
"First period included in two-week WQ reports to CVRWQCB
47
Ongoing spillway construction activities during the recovery phase are unlikely to
result in direct impacts to turbidity. Work activities in the main and emergency spillway
areas include blasting, excavation, rock crushing, pressure washing, grading, and
vegetation clearing, and all have the potential to contribute high levels of sediment to
surface waters without proper management and protection measures. Spoil piles lacking
erosion control barriers or disrupted ground surfaces impacted by precipitation events are
also likely to contribute to increased turbidity. However, California DWR has proposed
to implement best management practices, such as straw wattle installation, hydroseeding,
creating settling ponds, and creating erosion barriers to prevent any adverse effects to
turbidity. Monitoring conducted by California DWR indicates that these measures have
been effective in reducing construction-related impacts and remained low during the
early recovery phase from May to August 2017 (Figure 11). Therefore, turbidity levels
as a direct result of construction activities should remain low during the remainder of the
recovery phase ending in January 2019.
1000.0
A, HR
41!!!
LF(
A DP
100.0
X " X DP 300'ds
Dredging
o '900
A 4,
10„0
;1%,,Ack
,:k14,111"i',11,
4
1,0
20-Jan 9-Feb 1-Mar 21-Mar 10-Apr 30-Apr 20 May 9-Jun 29-Jun 19-Jul 8-Aug 28-Aug
Date
Figure 11. 7.10-2. Turbidity (in Nephelometric Turbidity Units) measured in the Feather
River in the high flow channel (HFC), low flow channel (LFC), Diversion Pool (DP), and
DP 300 ft. downstream of the dredging in 2017. Note log scale on y-axis for turbidity
(source: California DWR 2018b).
48
Nonetheless, construction activities are likely to result in indirect short-term
adverse effects to water quality without proper erosion control. During the recovery
phase, California DWR proposes to install and utilize multiple concrete batch plants. The
operation of the batch plants, along with the heavy use of concrete and grout during
construction is likely to result in short-term adverse effects to water quality if not
properly contained, or if any concrete materials come into contact with surface waters.
California DWR also proposes to direct wastewater associated with construction
activities to settling ponds for construction-related wastewater, which are located at the
base of the main spillway. California DWR has an operational protocol for the ponds,
which includes monitoring and managing water levels and regularly removing water from
the pools for dust control activities during recovery-phase construction activities.
However, California DWR did not provide any information on the long-term disposition
of the ponds, and a subsequent breach of the dike from use of the main spillway after the
completion of construction is likely to cause a spike in turbidity or an exceedance in other
water quality parameters. Accordingly, California DWR should be required to file a plan
for final disposition of the ponds and what measures it will implement to prevent
contaminated water from the settling pools at the base of the main spillway from being
discharged to the Thermalito Diversion Pool once construction has been completed.
Finally, after construction activities conclude, there are likely multiple
construction-use locations where sediment is likely to be introduced into surface waters.
Notably, the large spoil piles in the spillway area and near the Thermalito Diversion
Dam, along with the rock crushing site and bare hillsides and roads all feature exposed
surfaces prone to erosion and elevated turbidity in the project area. Therefore, California
DWR should also be required to develop a post-construction water quality protection
plan. The plan should include measures to prevent erosion at any area impacted by
construction efforts. At a minimum, the plan should contain measures for long-term
disposition of the spoil piles, disrupted soil surfaces, and any other sediment sources.
This plan should be combined with California DWR's plans for the final disposition of
the settling pond below the main spillway.
Dissolved Oxygen
Monitoring conducted by California DWR during its response and recovery
actions did not show any indication of adverse dissolved oxygen levels. Specifically,
monitoring conducted by California DWR during the response phase illustrates relatively
robust dissolved oxygen levels between 9.53 and 20.5 mg/L in the Thermalito Diversion
Pool (FERC 2018). The high dissolved oxygen levels noted during the response period
are likely the result of turbulence and aeration caused by water cascading over the main
and emergency spillways. Following the end of spillway use on May 20, 2017, the
project resumed normal flow release operations. Therefore, there should be no effect to
dissolved oxygen levels during the recovery phase, and any fluctuations in dissolved
49
oxygen levels will be the result of normal project operations or normal seasonal
fluctuations.
pH
Monitoring conducted during the response period indicates that pH levels were
generally near-neutral (FERC 2018). Aside from construction materials meeting surface
waters, algal blooms, decomposition, or interactions with local geology affect pH levels
at the project naturally. Algal blooms typically occur in the warmer summer months,
followed by decomposition in the fall and winter, and may be affected by water levels or
flow. California DWR does not anticipate reducing water levels to critically low levels in
any project impoundments or the Feather River and thus, is unlikely to have an
appreciable effect on pH levels.
During the recovery phase, construction activities are likely to cause short-term
adverse effects to pH levels without proper protection measures. The reconstruction of
both the main and emergency spillways relies on concrete production and placement at
the site. Consequently, any water that comes into contact with wet concrete or concrete
wash will result in elevated pH levels. California DWR has proposed to contain concrete
and concrete wash activities with the use of settling ponds at the recovery site. Two
small settling ponds near the emergency spillway would be lined with plastic, thereby
limiting their ability to affect water quality at the site. As previously discussed, an
additional pair of settling ponds would be located at the base of the main spillway, and
separated from the diversion pool by an earthen berm. In order to prevent the formation
of high pH levels within the ponds, California DWR has proposed to agitate the water
with sprinklers to neutralize high pH, and monitor water quality at this location within,
and outside,of the settling pond to ensure that water quality is not adversely affected in
the diversion pool. Nonetheless, a breach of the two settling ponds from spillway
operation or construction demobilization would cause short-term adverse effects to pH
levels. As California DWR has not outlined a definitive plan for the ultimate fate of the
tainted water at this location; it should be required to provide a plan for the ultimate
disposition of wastewater and spoiled material associated with the use of the settling
ponds.
Water Temperature
Water temperature below Oroville Dam is directly correlated with reservoir
releases, and is managed to maintain compliance with the requirements of a biological
opinion from the National Marine Fisheries Service (2004) for operation of the State
Water Project. Water quality monitoring conducted during the first two months of the
response phase indicates that water temperatures in the ThermaIito Diversion Pool
remained cool between 6.8 and 13.9 Celsius (C). Similarly, water temperature in the
50
low-flow channel during the response period remained cool between 7.9 to 14.6 C, which
is Consistent with seasonal temperature patterns (Figure 12).
Following the response period, California DWR should resume its normal cycle of
flow releases, and related water temperatures are expected to follow normal patterns
associated with project operations. Therefore, the response and recovery actions should
not result in significant changes to water temperature at the project.
Feather Myer at MHe 61,6 (FRA)
F°.
L.)
I•
cp.
1 ,
„
Figure 12. Water temperatures in the Feather River low-flow channel during the
response period (Source: California Data Exchange Center 2018, as modified by
Commission staff).
Other Parameters
Finally, intermittent and heightened releases from the spillway and reconstruction
activities likely resulted in short-term elevated levels of metals and minerals, due to
erosion of the spillway area and mobilization of settled sediments in the Feather River
during high flows. Specifically, California DWR's water quality monitoring during the
response phase noted elevated levels of copper. However, these effects were short-term,
and subsided with the cessation of erosion and dredging activities. California DWR's
remaining recovery phase activities should not result in any further elevated metal or
mineral levels. Due to already low background levels of conductivity, petroleum-based
51
products, nutrients, and pathogens, there should be no departures from background levels
as a result of California DWR's response or recovery actions.
6.5.3 Staff Recommendations
In order to prevent short-term adverse effects to turbidity after recovery-phase
construction is completed, California DWR should be required to file a plan for final
disposition of the settling ponds below the main spillway. The plan should detail what
measures California DWR will implement to prevent contaminated water from being
introduced into the Thermalito Diversion Pool once construction has been completed.
California DWR should also be required to develop a post-construction water quality
protection plan. The plan should include measures to prevent erosion at any area
impacted by construction efforts. At a minimum, the plan should contain measures for
long-term disposition of the spoil piles, disrupted soil surfaces, and any other unstable
areas that are known to contribute to increased turbidity. These two plans should be
combined into a post-construction water quality protection plan.
6.6 Fisheries and Aquatic Resources
6.6.1 Affected Environment
California DWR's response and recovery efforts has the potential to affect aquatic
resources in Lake Oroville, the Thermalito Complex, Feather River, and the OWA. The
Lake Oroville fishery is comprised of both cold water and warm water species. The cold
water fishery is managed as a put-and-grow fishery, with chinook salmon being planted
regularly, and joining an existing coho salmon, rainbow trout, and brown trout
community. The warm water fishery however, is self-sustaining, and is primarily
comprised of black bass (spotted bass, largemouth bass, smallmouth bass), catfish,
crappie, bluegill, green sunfish, carp, wakasagi, and threadfin shad. Terrestrial
vegetation along the reservoir shoreline provides spawning habitat, nursery habitat, and
refugia for warm water fishes, but becomes unavailable to fish as the reservoir is drawn
down during the summer months.
Downstream, the Thermalito Diversion Pool is predominantly a cold water fishery,
consisting of rainbow trout, brook trout, brown trout, and Chinook salmon. The
diversion pool also contains several native and non-native species, including common
carp, golden shiner, Sacramento pikeminnow, Sacramento sucker, wakasagi, prickly
sculpin, bluegill, black crappie, largemouth bass, smallmouth bass, and tule perch. The
diversion pool also has contained a relict coho salmon population from prior stocking
events in Lake Oroville that have passed downstream. However, the diversion pool fish
community and abundance thereof was likely altered by the exceptionally high flows and
turbidity levels following the main spillway failure. The Thermalito Forebay and Fish
Barrier Pool exhibit similar fish communities.
52
The Thermalito Afterbay provides habitat for cold water and warm water fish, and
is stocked occasionally with surplus steelhead from the Feather River Hatchery. Other
fish species observed in the Thermalito Afterbay include largemouth bass, smallmouth
bass, rainbow trout, brown trout, bluegill, redear sunfish, black crappie, channel catfish,
carp, and large schools of wakasagi. The Thermalito Afterbay provides good habitat and
forage for black bass, but recruitment is limited, due to reservoir elevation fluctuations
from pump-back operations.
The Feather River Fish Hatchery consists of the Fish Barrier Dam, fish ladder,
holding tanks, hatchery buildings, and raceways. The hatchery was constructed tin 1967
to compensate for the loss of salmonid spawning habitat upstream of Oroville Dam. The
hatchery is operated by the California DFW, which annually produces approximately 8
million fall-run Chinook salmon, 5 million spring-run Chinook salmon, and 400,000
steelhead. The hatchery utilizes cool water from the Thermalito Diversion Pool, which is
managed and monitored to maintain compliance with a 1983 operating agreement with
the California DWR and California DFW. Salmon and steelhead raised in the hatchery
are transported and releases into the downstream Feather River, Sacramento River, Lake
Oroville, Thermalito Afterbay, other California Reservoirs, San Pablo Bay, and most
recently, the San Joaquin River.36
The Feather River, downstream of the Fish Barrier Dam is primarily managed to
benefit cold water fisheries, and is designated in two distinct reaches known as the low-
flow and high-flow sections. The low-flow section of the Feather River has a minimum
flow requirement of 600 cfs, and starts at the fish barrier dam and continues downstream
to the confluence with the Thermalito Afterbay outflow. The high-flow section consists
of the portion of the Feather River downstream of the Thermalito Afterbay confluence,
and contains higher flows, which are supplemented from the afterbay releases and
contributions from the downstream Yuba River, Bear River, and Honcut Creek. Water
temperature in the low-flow section is also generally cooler than that of the high-flow
section.
Habitat in Feather River below the fish barrier dam is generally sediment-starved,
as a result of sediment in the upper watershed settling out in Lake Oroville.
Consequently, the riverbed is increasingly coarse in the upper portions of the low-flow
section of the river, which results in reduced formation of riparian vegetation in the
upper, low-flow section. In similar manner, the Feather River below the project has a
limited amount of large woody debris for fish habitat, which is trapped by Lake Oroville
upstream.
36 San Joaquin River Restoration Program:
http://www.restoresjr.net/?wpfb d1=2012
53
Fish species of primary management concern present in the Feather River include
spring-run Chinook salmon, fall-run Chinook salmon, Central Valley steelhead, rainbow
trout, brown trout, brook trout, green sturgeon, striped bass, river lamprey, American
shad, hardhead, Sacramento splittail, largemouth bass, smallmouth bass, and spotted bass.
Chinook salmon are very abundant in the Feather River; as an estimated 30,000 to
170,000 Chinook salmon spawn in the Feather River annually. Fall-run Chinook salmon
enter the Feather River in late summer and fall, and typically spawn in late September
through December. Spring-run Chinook salmon normally begin migrating in March and
continue through early September, and hold in cold water pools until ready to spawn in
the fall. The spring-run evolutionarily significant unit (ESU) is listed as threatened under
the ESA, and is discussed further in section 6.8-Threatened and Endangered Species.
The fall-run ESU qualifies as a species of concern and is considered significantly
depressed from historic levels.
Rainbow trout/steelhead are native to the Feather River, with the anadromous form
(steelhead) being federally-listed as threatened under the ESA. The Feather River
- contains both resident rainbow trout and the anadromous steelhead form. Most rainbow
trout spawn between February and June, with the steelhead form migrating to the project
area between September and November, and spawning in late December. Two species of
sturgeon (white sturgeon and green sturgeon) are also found within the project area, with
white sturgeon being more common of the two. Both sturgeon species begin upstream
spawning migrations between February and June, with spawning occurring between April
and June. White sturgeon are known to spawn in the Feather River, but the presence of
green sturgeon in the Feather River has historically, been contested. Additional
discussion regarding ESA-listed Central Valley steelhead and green sturgeon is provided
in section 6.8-Threatened and Endangered Species.
The Feather River in the project area contains striped bass, American shad, and
two lamprey species, including river lamprey and Pacific Iamprey. Striped bass is an
introduced migratory fish, which spawns in the project area from April through June, and
is an important recreational fishery in the Feather River. Similarly, American shad are an
introduced migratory species, which migrates to the Feather River primarily in May and
June. Juvenile American shad are present in the Feather River through mid-December,
with emigration peaking in August and September. Among the two lamprey species,
Pacific lamprey are more common in the Feather River than river lamprey. Both species
reside in freshwater for 3-4 years as ammocoetes, before metamorphosing to the adult
form, and migrating to the ocean. River lamprey then reside just upstream of saltwater
for 4 months, and then spend an additional 3 months in saltwater before returning to
freshwater to spawn in the fall. Pacific lamprey migrate to the ocean in the fall, where
they reside for 3.5 years, before returning to freshwater in April through June, residing in
the river over winter, and spawning the following spring. Additional species present in
upstream impoundments, such as black bass, minnows, suckers, sunfish, forage fish,
54
catfish, perch, and crappie are also present in the Feather River, but make up only a small
portion of the Feather River fish community.
The OWA downstream of the fish barrier dam contains more than 75 ponds and
sloughs, along with wetland and riparian areas, totaling about 12,000 acres. The ponds
are replenished by Feather River seepage, and floods into the area during high flow
events. The OWA ponds, sloughs and wetlands are inhabited by channel catfish, white
catfish, bluegill, green sunfish, carp, white crappie, black crappie, and Sacramento
sucker. The ponds are also inhabited seasonally by Chinook salmon after high flow
events, but typically do not survive the warmer late spring and summer water
temperatures.
6.6.2 Environmental Effects
Aquatic resources in the project area have the potential to be affected through high
flows, ramping rates, habitat alterations, and water quality changes associated with the
response and recovery efforts. These effects are discussed below at each of the fisheries
affected by the response and recovery efforts, which include the Feather River, Lake
Oroville, Thermalito Diversion Pool, Feather River Fish Hatchery and the OWA.
Feather River
Habitat Quality and Sediment-Feather River
The initial failure of the main spillway and erosion of the emergency spillway
contributed a significant amount of fine sediment to the lower Feather River. While
sediment transport is an important factor in fluvial morphology, excessive sediment has
the can adversely affect aquatic resources through habitat loss, habitat alteration, shifting
of aquatic species, and degradation of spawning habitat. During the response period,
larger-sized sediment particles and coarse debris settled into the Thermalito Diversion
Pool. However, smaller silt-sized particles continued downstream below the Thermalito
Diversion Pool, causing immediate adverse impacts to the lower Feather River, as
demonstrated by the high turbidity levels observed during the response period.
Initially high sediment loads during the response period likely had a short-term
adverse effect on aquatic species through spawning habitat degradation. Substrate
spawning species, such as salmonids (trout, salmon, and steelhead) and cyprinids
(suckers and minnows) were likely adversely affected by sediment covering spawning
substrate or active redds. These effects were likely more pronounced in the low-flow
section of the Feather River, where suitable spawning substrate is available. Conversely,
broadcast spawning species, such as American shad, striped bass, and sturgeon do not use
the substrate directly for spawning activities. Although fertilized eggs or larvae from
broadcast spawners can settle in lower velocity areas (and would be adversely affected by
55
sediment settling on top of eggs and juveniles), these species were not likely adversely
affected by sediment deposition, due to later spawning times in April and May, when
sediment levels in the Feather River had subsided.
Subsequent high flow pulses with lower sediment loads later in the response
period likely transported some of this sediment into lower reaches of the Feather River,
where it settled out in slow-water habitats. Sediment settling out in the lower reaches of
the Feather River likely altered the habitat dynamic through creation of sediment bars and
islands in the channel, thereby altering aquatic habitat in the lower river. These sediment
accumulations would eventually be colonized by riparian species, but would also reduce
overall available aquatic habitat. This sediment accumulation and creating of additional
riparian habitat likely occurred in low-velocity sections of the Feather River and in the
lower gradient reaches of the Feather River near the confluence with the Sacramento
River.
In addition to the sediment introduced from erosion of the main spillway, elevated
sediment levels were also likely introduced into the Feather River from streambank
erosion or from the reported streambank failures along the Feather River. Consequently,
there was likely an adverse impact to aquatic habitat through a reduction of riparian and
aquatic habitat along the river margins, but also from habitat degradation in downstream
areas where sediments settled out. As discussed in section 6.3-Geology and Soil
Resources, it is unclear to what extent streambank failure occurred in the Feather River.
It is also unclear to what degree to what degree that sediment deposition in the lower
Feather. River occurred as a result of the main spillway failure, use of the emergency
spillway, and any streambank degradation. In order to assess the severity of these
impacts, California DWR should be required to develop a Sedimentation and Erosion
Assessment and Mitigation Plan. The plan should investigate the degree of sediment
deposition in the lower Feather River and its effect on the aquatic habitat availability and
aquatic habitat quality by comparing pre-and post-response effects. The plan should also
assess the extent of any streambank loss during the response period. Finally, the plan
should propose measures to mitigate for adverse effects to the lower Feather River from
sediment deposition and streambank degradation.
Stranding-Feather River
During the response period, California DWR implemented four intermittent flow
pulses in February through May 2017 to pass inflows from Lake Oroville, and to preserve
the integrity of the remainder of the main spillway. The proposed high flow events by
themselves, were within the range of normal project operations during a wet hydrologic
year. High flow events redistribute sediment and introduce or relocate large woody
debris throughout much of the Feather River. As a result of its timing, the high flow
events displaced juvenile Chinook salmon and steelhead in the Feather River. This
displacement had mixed effects, as it encouraged downstream migration to productive
56
floodplain and estuarine rearing areas. However, a portion of the salmonids displaced
were entrained and perished in isolated areas disconnected from the Feather River. The
magnitude of these effects is discussed below.
While the high flow releases that occurred during the response period are typical
of wet water years, the abrupt flow decreases were atypical, and adversely affected
fishery resources through stranding. California DWR implemented four sharp flow
reductions, with the largest decrease from the main spillway dropping from 60,000 cfs to
0 cfs almost instantaneously on February 28, 2017 (Figure 15). The four flow reductions
were partially attenuated by flows from storage in the Thermalito Diversion Pool, but still
resulted in significant water level reductions in both the low-flow and high-flow sections
of the Feather River (Figure 13). Consequently, the high flows in the Feather River
initially displaced juvenile salmonids, followed by many becoming terminally stranded
along stream margins in standing water that became disconnected from the main channel.
Juvenile salmonids and other small fish with poor swimming ability were the most
adversely affected by the flow reductions, but a subset of other species and life stages
were also adversely affected by the flow reductions.
In coordination with the project operation staff, California DWR staff, together
with state and federal fish and wildlife agencies, conducted fish rescue operations as
spillway flows decreased. Monitoring conducted by the California DWR indicates that a
large variety of fish species were adversely affected by the aforementioned flow
reductions in February-May 2017 (Table 2). While an extrapolation of these data to
actual amount of fish mortality is difficult due to small sample size, inconsistencies in
representative sites; and sampling inefficiency; the data indicate that the four sharp flow
reductions had an adverse effect on the Feather River fishery.
57
LFC Quarterly Hour Flow
140000 Fil.h Flow Channel 6 uarterl Hour Flow
1
120000 i
1 1
ol 1
E 100000
01.)
'0
C
E 11
v°1 80000
k
II
1 11
1 60000 1 1:
4,0
11
C 1
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:L
I 1 1
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1 1 11111.I
. ,
12/31/2016 1/31/2017 0:00 2/28/2017 0:00 3/31/2017 0:00 4/30/2017 0:00 5/31/2017
0:00
Figure 13. Hydrograph showing flows in the Feather River during the response period
(Source: California DWR 2018)
The most abundant species of fish stranded in isolated pools included Sacramento
sucker, sculpin, various cyprinid minilliodws wakasagi (pond smelt), and juvenile Chinook
salmon. Of the more abundant mortalities
'observed during stranding surveys, the
represented taxa are relatively common native in the Feather River (sculpin, cyprinid Californiaminnow) or non-native (wakasagi). DWR's mortality and rescue numbers also
indicate that 12.6 percent of observed fall-run Chinook juveniles, 4.2 percent of the
observed spring-run Chinook, and 1.4 percent of observed stranded steelhead perished
during the sharp flow reductions (Table 2). Additionally, California DWR estimates that
267,894 to 346,469 fall-run Chinookjuveniles were stranded during rapid flow decreases
during the response period. Thoughother species perished during the event, these three
salmonids are those most actively-managed by state and federal resources agencies and
warrant mitigation for any losses. The effects to federally-listed species are discussed in
greater detail in section
6.8-Threatened and Endangered Species,
•
58
Table 2. Count of all fishes rescued (live), mortalities (dead), and the Total catch at all
stranding sites between February 27 and March 15, 2017, organized by Family. The total
of each column is summarized in the bottom row (Source: White et al. 2017).
Family Common Name Scientific Name Native •Live Dead Total
•
Catostomidae: Sacramento Sucker Catostomus occidentalis Yes 200 266 466
Suckers
Green Sunfish Lepomis cyanellus No 1 0 1
Warmouth Lepomis gulosus No 20 0 20
Bluegill Sunfish Lepomis macrochirus No 138 23 161
Redear Sunfish Lepomis microlophus No 19 0 19
Centrarchidae: Unidentified Sunfish(Juv.) Unidentified Centrachid (Juv.) -- 10 43 53
Sunfishes/Basses Unidentified Sunfish(Adult) Unidentified Centrarchid -- 0 12 12
Small Mouth Bass Micropterus dolomieu No 4 1 5
Largemouth Bass Micropterus salmoides No 3 0 3
Unidentified Crappie Pomoxis sp. No 1 0 1
Unidentified Bass(Juv.) Unidentified Centrarchid (Juv.) No 6. 0 6
Prickly Sculpin Cottus asper Yes 34 0 34
Cottidae: Scuplins Unid Sculpin(Juv.) Cottus sp. (Juv.) Yes 450 1,655 2,105
Common Carp Cyprinus carpio No 4 0 4
Hitch Lavinia exilicauda Yes 8 2 10
Hardhead Mylopharodon conocephalus Yes 76 0 76
Cyprinidae: Golden Shiner Notemigonus crysoleucas No 21 3 24
Minnows Sacramento Squawfish Ptychocheilus Lucius Yes 25 19 44
Hardhead 1 Sacramento Squawfish Unidentified Cyprinid spp. (Adult) Yes 0 6 6
(Adult)
Unid Minnow(Juv.) Unidentified Cyprinid spp. (Juv.) -- 336 1,016 1,352
California Roach Hesperoleucus symmetricus Yes 4 0 4
Embioticidae: Tule Perch Hysterocarpus traski Yes 145 32 177
Surfperches
lctaluridae: Bullhead Catfish Ameiurus sp. No 1 0 1
Bullhead Catfishes Unid Catfish (Juv.) lctaluridae spp. (Juv.) No 0 3 3
Osmeridae: Smelts Wakasagi Hypomesus nipponensis No 3,129 1,736 4,865
Percidae: Darters Bigscale Logperch Percina macrolepida No 0 1 1
Petromyzontidae: River Lamprey Lampetra ayresi Yes 0 200 200
Lampreys Unid Lamprey(ammocete) Lampetra sp. Yes 36 105 141
Poeciliidae: Western Mosquitofish Gambusia affrnis No 120 0 120
Live Bearers
CHNF: Chinook Salmon (Fall) Oncorhynchus tshawytscha Yes 3,853 554 4,407
CHNLF: Chinook Salmon(Late Fall) Oncorhynchus tshawytscha Yes 13 8 21
CHNS: Chinook Salmon (Spring) Oncorhynchus tshawytscha Yes 68 3 71
CHNW: Chinook Salmon (Winter) Oncorhynchus tshawytscha Yes 2 0 2
Salmonidae: CHN-A: Chinook Salmon (Adult) Oncorhynchus tshawytscha Yes 1 4 5
Salmonids RBTC-Y: Steelhead(FRFH Yearling) Oncorhynchus mykiss Yes 16 4 20
RBTC-A: Steelhead (FRFH Adult) Oncorhynchus mykiss Yes 4 12 16
RBTS-F: Steelhead(Wild Fry) Oncorhynchus mykiss Yes 1 0 1
RBTS-Y:Steelhead(Wild Yearling) Oncorhynchus mykiss Yes 20 11 31
RBTS-A:Steelhead (Wild Adult) Oncorhynchus mykiss Yes 10 9 19
Total 8,780 5,728 94,508
59
Comparison of the stranding estimates to the number of hatchery-released fish in
2017 indicates that stranding played a small, but significant part of the 2016-2017
hatchery-produced juvenile salmonid population; representing about 3.I percent of the
nearly 11 million fall-run juveniles likely produced during 2016-2017. California DWR
states that any losses to Chinook salmon would be offset by high flows that transported
juveniles downstream to productive rearing areas on the Sutter and Yolo Bypasses.
California DWR also states that prolonged high flows provided localized floodplain
habitat in the Feather River that is beneficial for rearing. California DWR also explains
that subsequent re-inundation of many ponded areas in the Feather River during high
flow events after the initial flow reduction in late-February, likely re-inundated many
ponded areas, and liberated the great majority of stranded fish. Finally, California DWR
states that fall-run Chinook salmon losses would also be offset by the additional 2 million
juveniles produced by the hatchery and released during 2018, and extraordinary efforts to
document and salvage fish during the Iate winter and spring of 2017. Commission staff
concur with California DWR's assertion that fall-run Chinook mortality was adequately
mitigated by these factors.
In addition to the above salmonid species, the Feather River hosts a robust
population of white sturgeon, striped bass, and American shad. White sturgeon are
expected to be present in the Feather River during the response and recovery period, and
were detected by sonar surveys at several location throughout the Feather River.
However, no white sturgeon were observed during fish stranding surveys or in
subsequent environmental DNA (eDNA) sampling of remaining pools in the high and
low flow channels. Spawning white sturgeon are also favor areas of high water velocity
and large substrate (Parsley et al. 1993), which is uncharacteristic of the habitat along the
river margins where stranding of other fish species occurred. Therefore, white sturgeon
present in the Feather River during the flow reductions were unlikely to have been
affected through stranding of adult spawning individuals.
Striped bass migrate to the Sacramento River near the project area in April and
May,just before spawning, with actual spawning dependent on water temperatures
(Stevens et al. 1987). Similarly, American shad migrate to the project area in April and
May, followed by spawning in May to July, but are also dependent on water temperatures
(Stevens et al. 1987). Review of California DWR's fish stranding data does not include
any observations of either species. As noted above, the final flow reduction was in mid-
May, when both species were likely arriving in the Feather River. However, arrival and
spawning was Iikely delayed in 2017, due to low water temperatures associated with
exceptionally high flows. As a result, it is unlikely that there was any significant level of
stranding on striped bass or shad. California DWR resumed normal project operations in
mid-May and any juveniles produced by either species were not likely not have been
adversely affected through flow manipulations.
60
With regard to the remaining native and non-native fish observed during standing
surveys, California DWR's stranding surveys noted high numbers of wakasagi and
sculpin, and unidentified minnows. These species are considered somewhat prevalent in
the project area, and as in the case of wakasagi, are non-native and compete with and /or
hybridize with native species for resources (Fisch et al. 2014). Among the sensitive
species (hardhead and hitch), observed mortality levels appear to be relatively low (0 and
2, respectively), and when qualitatively extrapolated for river-wide losses, should not
represent a significant loss to the fishery community.
Mitigation Activities-Feather River
California DWR has undertaken various actions to minimize or mitigate for the
loss of fall-run Chinook during the response period, such as fish rescues, habitat
improvements, and additional hatchery production. As part of the stranding surveys,
California DWR returned fish to main channel of the Feather River. Among the salvaged
fish, California DVVR returned all observed stranded fish to the Feather River. Though
not detailed in California .DWR's filing, in the fall of 2017, California DWR undertook a
habitat restoration project by releasing 5,000 cubic yards of spawning gravel into the
Feather River near the hatchery and excavating a river side channel to restore river flow
in the key spawning area. California DWR estimated that several hundred Chinook
salmon utilized the restored habitat during fall 2017.37 In addition, the California DFW
increased production from the Feather River Hatchery, in collaboration with California
DWR. California DWR reports that it plans to release an additional 2 million juvenile
fall-run Chinook in in 2018. The additional fish are on schedule for release during spring
2018, with 1 million juveniles each to be released in the San Francisco Bay and the
Feather River. These activities should adequately offset the direct effects to fall-run
Chinook salmon losses from stranding during 2017, but also benefit other species such as
spring-run Chinook salmon, steelhead, and resident rainbow trout.
Oroville Wildlife Area
The high flows observed during the response period likely had mixed effects to
fishery resources in the ponds located in the OWA. The high flows likely recharged
some of the ponds and pools located close to the main river with water high in dissolved
oxygen, but also deposited sediment in those same ponds and pools. Additionally, high
flow likely displaced some warm water species from the OWA ponds, which were later
observed in stranding surveys in the Feather River; some of which were stranded in
diminishing pools and perished. The same flows however, were likely to have introduced
forage species (wakasagi) and provided refuge and beneficial rearing habitat for juvenile
salmon; some of which likely remained permanently isolated, and some of which were
37 https://www.water.ca.gov/News/Blog/All-Blog-Posts/Update---Feather-River-
Salmon-Spawning-Restoration-Project (accessed March 13, 2018).
61
later reintroduced to the main Feather River during subsequent flow increases during the
response period. No additional effects to fishery resources in the OWA should occur
during the recovery period; as flows should not reconnect to the ponds, and no
construction activities would occur near OWA ponds.
Feather River Fish Hatchery
Following the initial failure of the main spillway, high turbidity levels and
sediment in the Feather River entered the Feather River Hatchery water supply system.
In an effort to protect fish located in the hatchery, the California DFW began to relocate
juvenile fish to the Thermalito Annex Fish Facility, located just west of the Thermalito
Afterbay. This extraordinary effort resulted in approximately 2 million spring-run
Chinook salmon and 4.2 million fall-run Chinook salmon being transferred to the
additional facility. At the Feather River Hatchery, the California DFW also implemented
various measures to preserve the fish that remained on site, including: creating a sediment
settling basin within the hatchery rearing channel; developing an alternate water source
using a filtration system and domestic water from a fire hydrant; cleaning out mud in the
incubation stacks and inland ponds; monitoring and maintaining turbidity and water
quality, using medicated and probiotic feed; adding salt to prevent disease; and cleaning
raceways.
The actions of the California DFW preserved many fish, but the overall event,
including elevated turbidity and sedimentation in the hatchery resulted in delayed
development and mortality. California DWR states that the Feather River Hatchery
collected and raised additional salmon and steelhead for release during the 2018 season.
Review of the projected numbers for salmon and steelhead released during 2018
illustrates that 670,000 yearling steelhead are scheduled for release during 2018. This
figure is approximately 300,000 more than required for Oroville Dam mitigation. For
Chinook salmon, the California DFW has a production goal of 6-7 million fall-run smolts
and 2 million spring-run smolts annually. In 2017, approximately 5 million fall-run and
1.7 million spring-run Chinook salmon were released; representing a deficit of 1-2
million fall-run and 300,000 spring-run smolts. California DWR states that in 2018, an
additional 2 million fall-run Chinook would be released from the hatchery (in addition to
the normal 6 million fall-run quota).
Review of the hatchery loss and production data indicate that any hatchery losses
of fall-run Chinook salmon would be mitigated with increased production in 2018.
Nonetheless, there is still a deficit of 300,000 juvenile spring-run Chinook from 2017 •
hatchery losses. Consequently, California DWR should be required to mitigate for this
loss of spring-run Chinook. Staff recommended mitigation measures include increased
hatchery production in a subsequent year, habitat improvements, or capital investment in
fishery projects. Any mitigation should be combined with other important fishery
mitigation or improvements required in this proceeding. Additional effects to federally-
62
listed fish in the Feather River Hatchery are discussed in section 6.8-Threatened and
Endangered Species.
Lake Oroville
In Lake OrovilIe, any impacts to aquatic resources are likely to result from
management of lake elevations for public safety, and to facilitate construction efforts. As
noted above in section 6.5-Water Quantity, California DWR would lower the Lake
Oroville elevation/storage levels during the 2017 and 2018 construction seasons to reduce
the probability of having to exercise the main spillway. Without the reservoir drawdown,
Lake Oroville would have remained high for much of 2017 and 2018, but gradually
depleting for minimum flow releases, water deliveries, water quality, and downstream
delta habitat requirements. The reduced water levels would in turn, reduce habitat for
aquatic species in Lake Oroville; particularly those that utilize habitat along the lake
margins, such as black bass and sunfish. Although these reductions would be substantial,
they are within the operational range of a dry water year, and would still be well above
the drought conditions that preceded the wet water years that led up to the spillway
failure. Therefore, no mitigation should be required at this time for fishery impacts to
Lake Oroville.
Thermalito Diversion Pool
The fishery in the Thermalito Diversion Pool was adversely affected through high
flows, habitat loss, and high sediment/turbidity load. At its highest point, releases over
the main spillway during the response period were in excess of 100,000 cfs. These high
flows likely displaced fish from the Thermalito Diversion Pool and into the Feather River
or to the Thermalito Forebay. This displacement was evidenced by the several adult
Chinook salmon found out of season during stranding surveys that appeared to have been
landlocked in Lake Oroville and/or the Thermalito Diversion Pool, but were displaced
with high flows.
Similarly, high sediment load and construction activities likely had an adverse
effect to aquatic resources in the Thermalito Diversion Pool and beyond. Initially high
sediment loads, such as those caused by excessive erosion of the spillway areas would
have forced fish to avoid the area and seek refuge in areas of lesser turbidity. The
additional dredging activities and flow pulses likely further exasperated those effects. In
consideration of the high flows, high turbidity, and dredging activities in the Thermalito
Diversion Pool, there were adverse effects to fishery and other aquatic resources in the
diversion pool. Notably, any fishery that was present in the immediate area of the project
spillways and dredging areas was likely displaced downstream by high flows or obliged
to emigrate from the area to avoid high turbidity levels. Similarly, fish residing in the
small tributaries to the diversion pool (primarily native cyprinids) were likely displaced
during construction activities associated with culvert replacements along Burma Road
63
Since the fishery in the diversion pool and its tributaries is not actively managed
through fish stocking or habitat improvements, the fish community therein is a function
of individuals introduced from Lake Oroville during spill events and from the pre-
existing fish community in Thermalito Diversion Pool and the connecting ThermaIito
Forebay. Thus, we expect that any impacts to the fish community in the diversion pool
and its tributaries will be mitigated as individuals immigrate from the ThermaIito Forebay
or are displaced from Lake Oroville during spill events, and also through natural
reproduction of remaining species in the diversion pool.
Ongoing Construction Effects
During response activities, California DWR designated an area west of the
Thermalito Diversion Pool for mobilizing watercraft and dredging equipment, along with
removing and hauling dredged material to an adjacent spoil pile. As part of these
activities, California DWR installed vertical pilings and expanded an equipment
utilization area,just upstream of the railroad bridge. Unfortunately, the expansion of the
shoreline area resulted in the partial fill of a permanent pond,just west of the staging
area. With the completion of dredging activities, California DWR should be required to
restore the pond to pre-project conditions, including removing the material that was
introduced to facilitate dredging efforts. This measure should be incorporated into the
project-area-wide Restoration Plan discussed in section 6.7-Terrestrial Resources.
There should not be any additional significant adverse effects to fishery resources
as a result of ongoing construction efforts in 2018. The above discussion notes some
potential, but minor effects to Lake Oroville aquatic resources through reduced reservoir
elevations, but is considered within historic operating patterns. Similarly, we expect
minor to no effects to aquatic resources in the Thermalito Diversion Pool during the
recovery phase through some ongoing dredging in 2017, but not in 2018. Finally, there
should not be any adverse effects to fishery resources in the Feather River Hatchery or
Feather River during the recovery phase, as project operations and river conditions
should remain within the normal range of operating conditions.
6.6.3 Staff Recommendations
In summary, failure of the main spillway and use of the emergency spillway
resulted in substantial adverse effects to fishery resources in the Feather River. Adverse
effects occurred in the Thermalito Diversion Pool, Feather River Fish Hatchery, and the
downstream Feather River through exceptionally high sediment loads, sharp flow
reductions, and degraded habitat quality. California DWR has implemented immediate
measures to offset these effects, but also plans additional future mitigative measures. To
fully mitigate for potential outstanding effects to fishery resources, California DWR
should be required to develop a Sedimentation and Erosion Assessment and Mitigation
64
Plan. The plan should investigate the degree of sediment deposition in the lower Feather
River and its effect on the aquatic habitat availability and aquatic habitat quality by
comparing pre-and post-response effects. The plan should also assess the extent of any
streambank loss during the response period, and should propose measures to mitigate for
adverse effects to the lower Feather River from sediment deposition and streambank
degradation. Finally, California DWR should be required to restore the pond located
west of the Thermalito Diversion Pool railroad bridge to pre-project conditions.
6.7 Terrestrial Resources
6.7.1 Affected Environment
The project is Iocated within the Sacramento Valley and Sierra Nevada Foothills
on land designated as a State Recreation Area. Vegetation in this area differs with
elevation changes from the valley floor (elevation 100 feet msl at the Iower end of the
OWA) to the upper elevation of the mountain range (about 1,200 feet above msl). The
vegetation changes from valley grasslands to foothill woodlands (characterized by blue-
oak /foothill pine woodlands with varying amounts of chaparral) to mixed conifer forests
in the higher elevations.
Botanical Resources
At the time of relicensing, botanical field investigations included surveys for
vegetation mapping, noxious weeds, special-status plant species, and riparian and
wetland resources. Surveys were conducted during 2002, 2003, and 2004. The study
area for the vegetation community/land use mapping included the area within the project
boundary, a 1-mile-area beyond the boundary, and the Feather River floodplain (within
the FEMA 100-year floodplain) downstream of the project boundary.
Seven natural vegetative community types were identified in the study area:
upland forest/woodland; upland herbaceous; upland shrub/scrub; riparian
forest/woodland; riparian shrub/scrub; wetlands; and aquatic/submerged vegetation.
Other areas were mapped based on land uses, such as disturbed, agriculture, urban (or as
rock outcrop), and open water.
The majority of vegetation around Lake Oroville and the Thermalito Diversion
Pool consists of a variety of native mixed oak woodlands, foothill pine/mixed oak
woodlands, and oak/pine woodlands with a mosaic of chaparral. Primary species include
interior and canyon live oaks, blue oak, and foothill pine. The open areas within the
woodlands consist of annual grassland species. Also found around the Thermalito
Diversion Pool is scrub vegetation, consisting of mostly chaparral vegetation, which is
characterized by evergreen, tough waxy leaves. Common chaparral species include
whiteleaf manzanita, buckbrush, toyon, and scrub oak. Downstream of Oroville Dam and
65
the Thermalito Diversion Pool, vegetation around open waters of the Thermalito
Complex include emergent wetland types with annual grasslands on the surrounding
slopes.
Invasive and Noxious Weeds
A total of 219 species of non-native plants were identified within the project
boundary during relicensing surveys conducted in 2002 and 2003. Of these species, 39
are identified as noxious or invasive plants by the California Department of Food and
Agriculture, California Invasive Plant Council, U.S. Department of Agriculture, and the
Plumas National Forest. The largest concentration of noxious or invasive species is
located within the OWA. However, noxious and invasive species also occur in areas with
existing land disturbance near roads, trails, and in the immediate vicinity of the spillway
and power facilities.
California DWR notes that the species of greatest concern to native riparian and
wetland plant communities and wildlife habitat in the areas associated with the proposed
actions include giant reed, tree of heaven, scarlet wisteria, parrots feather, and Himalayan
blackberry. Tree of heaven is intermingled with the valley elderberry shrub, which
serves as habitat for the federally-threatened valley elderberry longhorn beetle in about
250 acres in the OWA.
Riparian and Wetland Habitat
About 3,238 acres of riparian forest/woodland occur within the project boundary.
More than 2,450 acres of Fremont cottonwood forest occurs within the area studied at the
time of relicensing; most of which occurs in the OWA. Around Lake Oroville, native
riparian habitats are restricted to narrow strips along tributaries, consisting mostly of
alders, willows, and occasional cottonwoods and sycamores. A small amount of riparian
vegetation occurs around the Thermalito Complex. The north shore of Thermalito
Forebay is lined with an about 50-foot-wide strip of mixed riparian species (mostly
willows) with an understory of emergent wetland vegetation. Cottonwoods and willows
occur in scattered areas around the high water elevation of Thermalito Afterbay
shoreline. During relicensing studies, 215 acres of riparian shrub habitat were mapped.
These shrub associations occur almost entirely along the Feather River directly upstream
and downstream of the Thermalito Afterbay outlet. They include a mix of species but are
predominately arroyo willow and sandbar willow. Non-native species, such as giant reed
and scarlet wisteria, are prominent in the riparian shrub community along the Feather
River upstream of the Thermalito Afterbay outlet in the low flow channel.
A total of 912 acres of wetland vegetation were mapped at the time of relicensing,
most of which occurs around Thermalito Afterbay. Less than 7 acres of wetland
vegetation occurs around Lake Oroville and the Thermalito Diversion Pool, mostly
66
associated with seeps and springs that are a natural part of the landscape above the high
water line (Table 3). About 42 acres of emergent wetland vegetation occur along the
edges of ponds in the OWA. Emergent wetland habitats are dominated by short, erect,
rooted hydrophytes (e.g., cattail, tule, bulrush), and occur in waters less than 6 feet deep.
Seasonal flooding restricts species diversity to those species adapted to anaerobic soil
conditions. Emergent wetland habitat, ranging from strips less than 50 feet wide to areas
over 0.5 mile wide, are found around Thermalito Afterbay, Thermalito Forebay, within
dredger ponds in the OWA, and in backwater areas along the Feather River. Emergent
wetlands are generally absent within the drawdown zone of Lake Oroville or within the
steeper drainages upslope from the reservoir.
Table 3. Total acres of wetland habitat found at project facilities
Thermalito Thermalito Thermalito Lake Oroville
Afterbay Forebay Diversion Oroville Wildlife
Pool Area
Bulrush <1 0 0 0 0
Cattail <10 0 0 0 <1
Mixed 234 10 0 <1 42
emergent
Rush 381 <1 0 <1 0
Rush/verbena 201 0 0 0 0
Verbena 36 <1 0 0 0
Seep/wet 0 0 <1 6 0
area
Totals 852 11 <1 6 42
Ninety-four percent of the wetland vegetation occurs around Thermalito Afterbay,
where a lower band of mixed emergent species resides. Waterfowl brood ponds
constructed in inlets of Thermalito Afterbay support emergent vegetation along much of
their shores.
Wildlife Resources
California DWR used the California Wildlife Habitat Relationships database to
determine that roughly 330 wildlife species may occur within the project boundary.
Generally, the project area provides seasonal or year-round habitat for a variety of
wildlife including mountain lions, bobcat, raccoons, beaver, mink, badger, gray fox,
weasels, coyotes, tree and ground squirrels, rabbits, deer, skunks, ringtails, bears, and
many species of waterfowl and birds native to the area. The project area provides year-
round habitat for several species of migratory birds, as well as non-native vertebrates
including bullfrog, house sparrow, bobwhite quail, ring-necked pheasant, rock dove, wild
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• turkey, European starling, opossum, black rat, Norway rat, house mouse, muskrat, red
fox, and feral pig.
California DWR notes that the Thermalito Complex provides resting and foraging
habitat for open water and diving waterfowl species such as the ruddy duck, bufflehead,
scaup, ring-necked duck, common goldeneye, and common merganser, which generally
does not occur in surrounding agricultural areas. Due to water level fluctuations and
recreational high-speed boat use at the project, habitat for nesting and brooding
waterfowl and nesting grebes, is limited in the Thermalito Afterbay.
The number of wildlife species located within the actual emergency project areas
will vary based on the work location, amount of previous disturbance, and the amount of
previous human activity.
Commission staff accessed FWS's Information for Planning and Consultation
system on May 9, 2018, and generated the following list of birds protected under the
Migratory Bird Treaty Act that are likely to occur within the proposed response and
recovery areas:
Table 4. Birds protected under the Migratory Bird Treaty Act in the project area.
Common Name Scientific Name Season(s)
Bald Eagle Haliaeetus leucocephalus Year-round
Black Rail Laterallus,jamaicensis Breeding
Black Swift Cypseloides niger Breeding
Burrowing Owl Athene cunicularia Year-round
California Spotted Owl Strix occidentalis Year-round
Calliope Hummingbird Stellula calliope Breeding
Flammulated Owl Otus flammeolus Breeding
Fox Sparrow Passerella iliaca Winterin_
Green-tailed Towhee Pipilo chlorurus Breeding
Lewis's Woodpecker Melaner.es lewis Winterin_
Loggerhead Shrike Lanius ludovicianus Year-round
Long-billed Curlew Numenius americanus Wintering
Nuttall's Woodpecker Picoides nuttallii Year-round
Oak Titmouse Baeolophus inornatus Year-round
Olive-sided Flycatcher Contopus cooperi Breeding
Peregrine Falcon Falco peregrinus Wintering
Rufous Hummingbird Selasphorus rufus Migrating
Rufous-crowned Sparrow Aimophila ruficeps Year-round
Short-eared Owl Asio flammeus Wintering
Snowy Plover Charadrius alexandrines Breeding
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Common Name Scientific Name Season(s)
Swainson's Hawk Buteo swainsoni Breeding
Western Grebe Aechmophorus occidentalis . Wintering
Williamson's Sapsucker Sphyrapicus thyroideus Year-round
Yellow-billed Magpie Pica nuttalli Year-round
There is an active bald eagle nest (Glen Pond Nest territory) located outside of the
project boundary, but in close proximity to areas as part of the response and recovery
efforts. The Glen Pond nesting territory was previously addressed as part of the approved
new alignment of the 230kV powerlines.38 The occupied nesting tree was determined to
be hazardous and thus removed.39 California DWR was required to make a reasonable
attempt to relocate the nest to a suitable tree within the eagle pair's territory.4D In
coordination with the FWS and the California DFW, California DWR installed a total of
four surrogate nest structures. In mid-January 2018, the Glen Pond nesting pair relocated
and built a new nest to the north side of the Thermalito Diversion Pool, in the same
general vicinity as their old territory.
Oroville Wildlife Area
The OWA is located west of the city of Oroville and is managed by the California
DFW, guided by the 1978 OWA Management Plan, as well as applicable state laws and
regulations. The OWA includes 6,000 acres including and surrounding the Thermalito
Afterbay, and the 5,000 acres adjacent to and spanning 12 miles of the Feather River.
The riparian habitat present within the OWA is the largest remaining block of riparian
habitat along the Feather River with further details discussed above, and provides
breeding habitat for a variety of neotropical migrant birds.
Habitats within the OWA differ from the other land associated with the emergency
work, as the area includes: lacustrine, riverine, freshwater emergent, valley foothill
riparian, and annual grassland and dryland grain/seed crops. Wildlife species are
relatively similar to the remaining project area and include: coyote, deer badger, fox,
bobcat, porcupine, squirrel, rabbit, osprey, white-tailed kite, egrets, woodpeckers,
warblers, dove, quail, and waterfowl.
38 Order Amending License, Revising Project Description, and Amending Project
Boundary (160 FERC ¶ 62,168), issued August 23, 2017.
39 California DWR Biologists requested an eagle take permit for Health and Safety
Reasons (Permit No MB22883C-0) to remove the primary nest and fell the nest tree.
4° Through coordination with the California Department of Parks and Recreation,
an Eagle Nest Exhibit Permit was received and the intact nest is on display at the Lake
Oroville Visitor Center.
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6.7.2 Environmental Effects
During the response phase, high flow releases from Oroville Dam; particularly in •
February 2017, adversely affected wetland areas within the OWA. Specifically, high
flows not only inundated fringe wetlands along the mainstem Feather River, but also
recharged many wetland ponds along the Feather River, and within in the OWA. The
high flows also redistributed and/or introduced varying levels of sediment to these
wetland areas, thereby providing an influx of nutrients to the system. In a separate filing,
California DWR notes that some of the inflow and outflow conveyances to wetlands
within the OWA were degraded during high flows, and requests Commission approval to
allow the Sutter Butte Flood Control Agency to repair, augment, or install structures that
would improve floodplain connectivity, reduce flood stage, promote fish and wildlife
habitat, enhance recreation, and reduce operation and maintenance costs.4' This proposal
was the subject of a separate Commission proceeding, and authorized on June 21, 2018.
California DWR also previously requested and received approval for rerouting the
project's primary transmission line,42 and for allowing PG&E to reroute a portion of its
transmission line across the project land near the Thermalito Diversion Pool.43 The
clearing and construction actions required by the two projects, in combination with
California DWR's current proposal, cumulatively had a significant adverse effect on the
above-mentioned resources. Given the duration of the response and recovery efforts,
there will continue to be mid-term, long-term, and permanent effects to vegetation,
wildlife, and wildlife habitat. The majority of the land clearing and loss of habitat is
temporary and will be mitigated over time through revegetation and other measures
described below.
The majority of the adverse environmental effects on terrestrial resources
associated with California DWR's subsequent recovery phase is a result of the
cumulative impact of the vegetation and land clearing required for the construction of
access roads, work pads, staging areas, spoil sites, and other supporting facilities; and the
specific proposals to construct the emergency spillway's RCC splash pad; install the
PG&E and California DWR emergency shoofly transmission lines; replace the 13.8-kV
powerline and fiber optic communication system; and install the boundary cattle fencing.
Vegetation and land clearing activities will have a direct and significant effect on nesting
birds, animal burrows, and habitat. The clearing of the natural and existing environments
41 In an April 2, 2018 filing, California DWR requests Commission approval to
permit the Sutter Butte Flood Control Agency to implement the Flood Stage Reduction
Project within the OWA.
42 Ibid.160 FERC ¶ 62,168.
43 Ibid. 160 FERC ¶ 62,118.
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increases noise, vibration, dust, and pollution, and introduces the possibility of
vehicle/wildlife collisions and other human interactions with wildlife. The loss of
vegetation will temporarily compound some of these effects.
Construction activities during the recovery phase of the Oroville Spillway
emergency will also temporarily and permanently disturb land, vegetation, and wildlife
resources within the project and surrounding area. California DWR estimates that more
than 300 acres of terrestrial habitat have, or will be impacted within the proximity of the
spillways. For the proposed borrow area, 380,000 cubic yards of material would be
coming from the spillway area. California DWR provided an estimate of disturbance
area totals for major project activities as shown in Table 5 below.
Table 5. Estimated disturbance area for major project activities
Feature Type Size (in acres or miles)
Access Roads 28.31 miles
Spoil Piles 41.17 acres
Crane Pads 0.83 acres
Concrete Batch Plants 7.47 acres
Kiewit Areas' 314.9 acres
In addition, the natural hillside used as part of the emergency spillway would be
replaced with a 5- to 10-foot-thick splash pad or apron of RCC, permanently removing
the natural woodland habitat that existed prior to the emergency event. However,
sufficient habitat exists in the areas immediately surrounding the project construction
area such that the majority of wildlife and avian species are expected to temporarily
disperse to less disruptive locations. With proper mitigation efforts implemented,
construction-specific effects would be minimized,
The above actions will increase vehicular traffic and necessitate the use of heavy
machinery such as excavators, bulldozers, front-end loaders, dump trucks, helicopters,
coring and drilling equipment, and explosives. The use of the facilities and equipment
increases human presence, noise, and pollution which has secondary minor short-term
adverse effects to the wildlife and birds and their habitats. Disturbance and removal of
existing vegetation for any of the proposed construction activities and the increased
vehicular traffic and human interaction in the proposed environments will also create
conditions conducive to the introduction and spread of invasive plant species. The
introduction and spread of these species will allow for the displacement of native
vegetation, thereby reducing biodiversity and altering compositions of existing native
as Kiewit Areas include the entirety of the FCO and Emergency Spillways, access,
staging, spoils, offices, etc. This is a general footprint for their project area.
71
communities, further adversely affecting existing botanical and wildlife habitat. If proper
mitigations techniques are implemented and the various work areas are restored to their
pre-emergency conditions this affect will be short-term; failure to do so will result in
long-term harm to the area.
•
The 2018 recovery-phase activities are also located near, but not directly within
the current Glen Pond nesting eagle territory. However, due to the fly over range and
foraging habits of the bald eagle, the proposed activities are likely to have a moderate
short-term adverse effect on the eagle pair as their food source will be displaced and the
area will have increased human activity. Bald eagles have been removed from the list of
threatened and endangered species since 2007, but are still protected at the federal level
under the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act. As
detailed in the Commission's Final Environmental Impact Statement (FEIS) for
relicensing the Feather River Project, California DWR previously implemented
conservation measures as a result of its draft programmatic biological assessment for
terrestrial species (FERC 2007). California DWR should continue to implement these
measures to prohibit human activity near the nests as the response and recovery efforts
take place and to ensure the protection of the Glen Pond eagle nesting territory.
California DWR has made efforts to reduce the environmental impact of required
support facilities by locating them in previously disturbed areas, such as license-required
recreation sites (see also section-6..10 Recreation Resources). If implemented, the best
management practices for construction and mitigation efforts identified by California
DWR and the fulfillment of permit requirements should reduce the overall effect on
terrestrial resources within the proposed project area. Additionally, in its recently
approved Revegetation, Planting, and Monitoring PIan45 for the 230-kV powerline
relocation, California DWR notes that it intends on creating a broader Oroville
Emergency Response and Recovery Project Area Restoration Plan to be completed and
implemented following the termination of construction activities.
6.7.3 Staff Recommendations
California DWR has implemented various construction-specific best management
practices to mitigate environmental effects, including: environmental pre-project surveys;
concurrent environmental monitoring; and staff environmental awareness training;
delineated exclusionary areas; implementing site specific speed limits; and site
stabilization, habitat restoration, and revegetation. California DWR should continue
these and other practices provided in its January 29, 2018 filing, throughout the
remaining recovery work.
45 Order Approving Revegetation, Planting, and Monitoring Plan
(162 FERC ¶ 62,176), issued March 26, 2018.
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As discussed above, the machinery and vehicles used during land-clearing
activities have the potential to introduce and spread invasive or noxious plant species.
California DWR and its contractors should use best management practices to reduce these
potential effects during both the response and recovery phases. Best management
practices include but are not limited to: assessing activity areas for existing invasive
species to avoid further spread, following decontamination procedures for equipment,
vehicles, and contractors entering and exiting work areas; preserving existing vegetation
and revegetating as soon as possible where feasible, and reducing soil disturbance and
potential erosion where feasible; etc. California DWR's use of post-construction
mitigation measures to restore cleared areas to pre-construction conditions, where
appropriate, will also aid in alleviating short- and long-term adverse effects on the
vegetative environment (including minimizing the spreading of invasive species) and
wildlife habitat.
Given the extensive land clearing associated with this proposal (see Table 5) and
cumulatively with the relocation of the PG&E and California DWR primary transmission
lines, staff agrees with California DWR that a comprehensive Restoration Plan should be
completed for the project. As such, staff recommends that California DWR develop
separately, or as part of that comprehensive plan, a Revegetation and Invasive Species
Mitigation Plan to include revegetation activities, mitigation for the spread of invasive
species, and monitoring of revegetation efforts. Implementing a comprehensive
Revegetation and Invasive Species Mitigation Plan will minimize long-term adverse
effects to surrounding vegetation and wildlife habitat, minimize the spread of noxious
weeds, promote the establishment of native communities, and protect identified special
status species from construction-related disturbances (see section 6.8-Threatened and
Endangered Species).
California DWR should also continue to implement the following measures to
prohibit human activity as the response and recovery efforts take place and to ensure the
protection of the Glen Pond eagle nesting territory, including implementation of: (I) an
administrative closure of land and shoreline areas to human entry during the nesting
season around the bald eagle nest territories; (2) signage, patrol, and enforcement of the
aforementioned closure; (3) nest and population surveys; (4) habitat improvement
measures; and (5) limitations on current and future habitat disturbance.
While the proposed response and recovery actions would likely result in mid-to
long-term adverse effects on the Feather River Project's terrestrial and botanical
resources, implementing the best management practices described in the
January 29, 2018 filing, the required mitigation outlined in the various permits obtained
to perform the construction work, and the above staff recommended measures, will lessen
both the direct and indirect effects. If implemented, the mitigation measures will ensure
that California DWR's actions have minimal disturbance to the areas at the time of
73
construction and where disturbance is unavoidable efforts to restore wildlife habitat are
taken in a timely manner.
6.8 Threatened and Endangered Species
6.8.1 Affected Environment
The California DWR's January 29, 2018 filing includes a list of the federally-
listed threatened and endangered species that may occur in the project area. This list was
compiled using information from the relicensing proceeding, and supplemented with data
from the California Natural Diversity Database and from a September 2017 search of the
FWS' online Information for Planning and Consultation database (IPAC). Commission
staff accessed the FWS' IPAC database on January 30, 2018, and did not find any
additional species known, or with the potential, to occur within the project area. Table 6
below provides a list of the federally-listed species that may occur in the proposed project
boundary and those with identified critical habitats.
Table 6. Federally-listed species that may occur in the project area.
Common Name Scientific Name Federal Status
Birds
Southern Bald Eagle Haliaeetus leucocephalus Delisted
Yellow-Billed Cuckoo' Coccyzus americanus Threatened
Least Bell's Vireo Vireo bellii pus illus Endangered
• Reptiles
Giant Garter Snake Thamnophis gigas Threatened
Amphibians
California Red-Legged Frog47 Rana draytonii Threatened
California Tiger Salamander Ambystoma californiense Threatened
Sierra Nevada Yellow-Legged Rana sierra Endangered
Frog
Fish
Delta Smelt Hypomesus transpacificus Threatened
California Central Valley Distinct Oncorhynchus mykiss Threatened
Population Segment (DPS)
Steelhead
Central Valley DPS Spring-Run Oncorhynchus tshawytscha Threatened
Chinook Salmon
46 Designated critical habitat is located in the project area.
47 Designated critical habitat is located in the project area.
74
Common Name Scientific Name Federal Status
Southern DPS North American Acipenser medirostris Threatened
Green Sturgeon
Insects
Valley Elderberry Longhorn Desmocerus californicus Threatened
Beetle dimorphus
Crustaceans
Conservancy Fairy Shrimp Branchinecta conservatio Endangered
Vernal Pool Fairy Shrimp Branchinecta lynchi Threatened
Vernal Pool Tadpole Shrimp Lepidurus packardi Endangered
Flowering Plants
Butte County Meadowfoam Limnanthes floccosa ssp. Endangered
Californica
Green's Tuctoria Tuctoria greenei Endangered
Hairy Orcutt Grass Orcuttia pilosa Endangered
Hoover's Spurge Chamaesyce hooveri Threatened
Layne's Ragwort Senecio layneae Threatened
Slender Orcutt Grass Orcuttia tenuis Threatened
Hartweg's golden sunburst Pseudobahia bahiifolia Endangered
Pine Hill Flannelbush Fremontodendron decumbens Endangered
The FWS issued a Biological Opinion on April 9, 2007 that addressed the effects
of issuing a new license for the Feather River Project on federally-listed threatened and
endangered species.48 The National Marine Fisheries Service issued a separate
Biological Opinion on December 5, 2016, which identified critical habitat for Central
Valley DPS of spring-run Chinook salmon, California Central Valley DPS of steelhead,
and the Southern DPS of North American green sturgeon in the Feather River extending
upstream to the fish barrier dam, but no farther.49
California DWR conducted habitat surveys during the relicensing process for the
Feather River Project, and a review of those surveys was performed to determine the
potential for threatened and endangered species habitat to occur within the emergency
response and recovery project area. The emergency response and recovery project area
does not contain vernal pools. As such, Commission staff will not consider the following
species in the environmental analysis of the emergency response and recovery action:
conservancy fairy shrimp, vernal pool fairy shrimp, vernal pool tadpole shrimp,
California Tiger salamander, Butte County Meadowfoam, Greene's Tuctoria, Hair Orcutt
48 The FWS's Biological Opinion was filed with the Commission on
April 16, 2007, under Project No. 2100-000.
49 The NMFS's Biological Opinion was filed under Project No. 2100-134.
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Grass, Hoover's Spurge, and Hartweg's Golden Sunburst. Habitat for the following
species does exist within the project boundary: the Layne's Ragwort, Pine Hill
Flannelbush, yellow-billed Cuckoo, and Giant Garter Snake; however, there is no
potential for disturbance to habitat for these species within the emergency response and
recover project area. Lastly, California Red-legged Frog, Sierra Nevada Yellow-legged
Frog, Delta Smelt, and the Least Bell's Vireo are either not known to occur within, or
have not been found within the project boundary. Consequently, Table 7 provides a list
of the federally-listed species, with identified critical habitat, that may occur in the,
emergency response and recovery project area.
Table 7. Federally-listed species potentially affected by the response and recover actions.
Common Name Scientific Name Federal Status
Birds
Southern Bald Eagle Haliaeetus leucocephalus Delisted
Fish
California Central Valley Oncorhynchus mykiss Threatened
Distinct Population
Segment (DPS) Steelhead
Central Valley DPS Oncorhynchus tshawytscha Threatened
Spring-Run Chinook
Salmon
Southern DPS North Acipenser medirostris Threatened
American Green Sturgeon
Insects
Valley Elderberry Desmocerus californicus Threatened
Longhorn Beetle dimorphus
Valley Elderberry Longhorn Beetle
The valley elderberry longhorn beetle was listed as a threatened species on
August 8, 1980, and if afforded full protection under the federal ESA.50 The current
range of the valley elderberry longhorn beetle extends throughout the Central Valley
from approximately Shasta County in the north to Fresno County in the south, and
includes the valley floor and lower foothills. Valley elderberry longhorn beetle habitat
consists of elderberry thickets located in riparian woodlands, oak woodlands, or
grasslands. Adult valley elderberry longhorn beetles deposit their eggs in the bark of
living elderberry plants and larvae bore into the pith of stems. The beetles' use of
elderberries is not readily apparent; often the only exterior evidence is an exit-hole
created by the larva just prior to pupation. A variety of branch sizes are used for larval
5° See Federal Register 45: 52803-52807.
76
development and pupation; although, stems 2-4 inches in diameter at the exit hole have
been reported to be used most often. Infrequently, exit holes have been found in smaller
branches less than 1.5 inches in diameter, but generally not in branches less than 1.0 inch
in diameter. Thus, larvae appear to be distributed primarily in large, mature plants with
stems greater than 1.0 inch in diameter near ground level.
At the time of relicensing, California DWR mapped and surveyed elderberry
shrubs using the FWS protocol. Survey results found that approximately 95 acres of
valley elderberry shrubs were delineated within the project boundary, with 0.402 acre
around Lake Oroville, 2.255 acres in the area downstream from the Oroville Dam and
north of Highway 162, and 91.831 acres in the OWA south of Highway 162 and Larkin
Road. Forty-five elderberry shrub stems greater than 1 inch in diameter (preferred size of
the valley elderberry longhorn beetle) were mapped along the Feather River corridor
between Oroville Dam and the Fish Barrier Pool and along the Thermalito Power Canal,
elderberry shrubs with stems greater than 5 inches in diameter in high density were
located along the levees within the portion of the OWA bordering the Feather River.
California Central Valley DPS Steelhead, Central Valley DPS Spring-Run Chinook
salmon, and Southern DPS North American Green Sturgeon
Adult California Central Valley spring-run Chinook salmon typically begin their
upstream migration in late January and early February, and arrive at the Feather River
Fish Hatchery between late April and June (NMFS 2016). The spring-run Chinook
salmon hold in large pools, especially in the low flow channel, upon arrival and through
the summer before spawning in the fall (NMFS 2016). A small number of spring-run
Chinook salmon remain in the Lower Feather River before emigrating in April and an
even smaller number appear to emigrate in the winter as yearlings (Bilski and Kindopp
2009). Spring-run Chinook salmon often selecting holding pools that have a large bubble
curtain at the head, underwater rocky ledges, and shade cover throughout the day.
Spawning, however, occurs in gravel beds less than 5 feet in depth in stream reaches
characterized by low gradient pool-riffle hydrology. Gravel size in spawning habitats is
typically 1 to 4 inches with less than 5 percent of fine material present (CDFG 1998).
The Feather River downstream of Oroville Dam is also listed as critical habitat for
California Central Valley DPS steelhead. In the project vicinity, most natural steelhead
spawning occurs in the low flow channel near Hatchery Ditch, a side change between
river miles 66 and 67, and additional spawning habitat is used below the Thermalito
Afterbay outlet. Juvenile steelhead emigrate beginning in February; however peak
emigration typically occurs in March or April. Adult California Central Valley steelhead
typically enter the Feather River from September to November, hold until spawning, and
begin spawning in the Lower Feather River in late December,peaking in late January
(NMFS 2016). Spawning is complete by the end of March (Cavallo et al. 2003).
Spawning typically occurs from late December through March, with subsequent egg
77
incubation occurring from December through April (NMFS 2016). Alevin emergence
occurs during March through May (NMFS 2016). Additional measures had previously
been implemented to increase the quality and complexity of salmonid spawning and
rearing habitat within the Feather River, via structural enhancements in the mainstem, in
existing side channels, and through the development of additional side channels. Gravel
supplementation projects have also been implemented to improve salmonid spawning
habitat downstream of Oroville Dam. Southern DPS North American green sturgeon
spawn in the Klamath and Sacramento Rivers (Moyle 2002), although there have been
intermittent reports of spawning in the Feather River(Seesholtz et al. 2014). The timing
of the spawning, however generally occurs between April and June (Adams et al. 2002).
The Feather River Fish Hatchery is an anadromous fish hatchery that was built in
1967 to mitigate for the loss of spawning grounds and rearing areas for returning
salmonids that resulted from the construction of Oroville Dam and water diversions in the
Sacramento-San Joaquin Delta. It is one of four Central Valley hatcheries producing and
releasing steelhead, and it is the only Central Valley hatchery producing and releasing
Central Valley DPS spring-run Chinook salmon. The Oroville Reservoir provides the
hatchery supply water and implements flow release measures to control water
temperatures and to operate the fish ladder, which allows for upstream migrating
salmonids to enter the hatchery for egg-taking or fertilization.
6.8.2 Environmental Effects
Valley Elderberry Longhorn Beetle
During the initial emergency response activities, California DWR biologists
surveyed the project area for elderberry shrubs suitable for valley elderberry longhorn
beetle habitat. On March 21, 2017, six elderberry shrubs were identified within the
action area (i.e., two at spillway left, one near Hyatt, one along Burma Road, and two
near the vicinity of Spoil Pile 3). The areas were flagged with 25-foot buffer zones and
construction crews were instructed to avoid the plants as much as possible.
On March 28, 2018, California DWR began to clear areas for emergency access
and staging to repair the damaged FCO spillway. California DWR informed the FWS
that one of the six previously identified shrubs was located in an area to be used at the
spillway left as a helipad. The 1-inch stemmed elderberry shrub did not have evidence of
exhibit holes, but needed to be relocated. California DFW removed the elderberry shrub
from this location and transplanted it to a location near the Thermalito Afterbay on
March 29, 2017. This location was chosen due to the existence of elderberry shrubs in
the area, California DWR fee ownership of the property, and because the area is managed
by the California DFW.
On April 13, 2017, California DWR contacted the FWS concerning a second
identified elderberry shrub found within the spillway left area that required transplanting.
78
The FWS responded on April 18, 2018, acknowledging the emergency situation at the
project and requesting that the California DWR contact them again to coordinate the.
long-term management of the transplanted elderberry shrubs. The spillway left shrub
was relocated to the OWA in close proximity to existing elderberry shrubs.
Both relocated plants are being monitored and are known to have survived through
the 2017 summer months. The remaining four identified elderberry shrubs are located
within non-riparian areas, are not located near other elderberry shrubs, and none
displayed exist holes.
California DWR worked with the California DFW to relocate the two shrubs
immediately and to locations that would not be affected by the actions taken. The
locations chosen are existing riparian habitats where known clumps of elderberry shrubs
exist. While there were direct impacts to the relocated elderberry shrubs individually at
the time of transplantation, it is not likely that the valley elderberry longhorn beetle
species were affected given the isolation of the plants, their location in a non-riparian
habitat, and the lack of exist holes.
Where avoidance and minimization measures outlined in its amendment
application are not possible for any future valley elderberry shrubs, California DWR
states it is developing an Elderberry Relocation Plan (utilizing comments received from
the FWS on November 30, 2017) to move elderberry shrubs to an already identified
mitigation site. The relocation plan would include planting additional elderberry shrubs
and associated species utilizing the FWS's most recent Framework for Assessing Impacts
to the Valley Elderberry Longhorn Beetle from 2017.5' California DWR states it would
monitor the plants for up to five years using the defined success criteria and
implementation measures, should it not meet success criteria.
California Central Valley DPS Steelhead, Central Valley DPS Spring-Run Chinook
Salmon, and Southern DPS North American Green Sturgeon
Hatchery
The February 2017 spillway failure and associated emergency response efforts
potentially affected federally-listed California Central Valley DPS steelhead, Central
Valley DPS spring-run Chinook salmon, and Southern DPS North American green
sturgeon. As discussed in section 6.6-Fisheries and Other Aquatic Resources, impaired
water quality and sediment build-up from spillway-area erosion specifically affected tile
Feather River Fish Hatchery. Approximately 2 million spring-run Chinook salmon that
were located at the hatchery had to be transferred to the Thermalito Annex during the
onset of the spillway failure. California DWR and hatchery staff took measures to
51 See hitti.)s://www.fivs.2ov/sacramento/documents/VEL.B. Framework.. df
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minimize mortality and to minimize impacts to the hatchery. As a result of hatchery
mortalities, the California DFW fell short of its 2017 stocking goals. In 2017, California
DWR stocked 1.7 million spring-run Chinook salmon, representing approximately 85
percent of the production goal. Even after accounting for increased hatchery production
in 2018, there remains a shortfall of approximately 300,000 juvenile spring-run Chinook
salmon. California DWR should be required to mitigate for this deficit.
The incident also compromised approximately 750,000 California Central Valley
steelhead eggs at the hatchery, as the eggs were too fragile to attempt to relocate and the
associated water filtration system failed during the event. The hatchery was able to treat
and use water from a fire hydrant in combination with its source water to decrease water
temperature and increase oxygen to the eggs, which resulted in minimal egg mortality.
Nonetheless, the hatchery increased steelhead production and stocking in 2018, and in
February 2018, the California DFW released 500,000 yearling California Central Valley
DPS steelhead into the Feather River and 170,000 yearlings into the Thermalito Afterbay,
which exceeded California DWR's corresponding mitigation criteria by approximately
300,000 fish.
Feather River
Following the spillway failure on February 7, 2017, California DWR consulted
with NMFS and California DFW regarding eroded debris and sediment. California DWR
proposed to shut down the flood control outlet spillway to allow the eroded material to be
removed via barge-mounted excavators. However, in doing so, California DWR
implemented rapid flow reductions and dredging activities. On February 24, 2017,
NMFS expressed concern regarding potential effects to special status species, and
recommended specific measures to be implemented during flow reductions. However,
California DWR indicates that it was unable to conform to all of the NMFS'
recommendations, citing the extensive emergency work that had to be done in a short
amount of time and its conflicting efforts to maintain and observe the structural integrity
of the remaining portion of the main spillway. The rapid flow reductions were
implemented on February 27, March 27, May 1, and May 18, 2017. California DWR was
able to provide minimum flows for in-river fish, implement protection measures for fish
housed at the hatchery, conduct stranding pool surveys, and perform fish rescues.
California DWR included its stranding survey results in its filing (Table 8). California
DWR however, was not able to reduce flows as slowly as requested, due to the risk of
increased head cut erosion. Based on its observations within the surveyed area, Table 8
also provides an estimate of the total numbers of fish standings in the affected areas.
The stranding surveys demonstrated short-term adverse impacts to steelhead in the
Feather River. California DWR estimates impacts to as many as 87 fry, 1,355 yearling,
and 676 adult steelhead were affected by stranding in the lower Feather River. As
discussed in section 6.8, these effects would be offset in part, by increased steelhead
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stocking in 2018, and through completed and planned habitat improvement efforts. In
addition, the stranding surveys estimates noted as many as 5,380 juvenile spring-run
Chinook salmon were stranded during the flow reductions. This lower amount (when
compared to the 1.7 million released to the river) likely represents the high proportion of
fish that had already out-migrated in 2017. Therefore, staff concludes that stranding from
sharp flow reduction did not likely play a large role in spring-run Chinook salmon
population reductions.
No adult or juvenile green sturgeon strandings were observed after flow reduction
events. Although juvenile green sturgeon juveniles were observed in May 2017
spawning surveys, no juveniles were noted in any of the fish stranding surveys.
Spawning green sturgeon typically inhabit deep fast water areas (Moyle 2002), and
would not have been as affected by the drawdowns as side channels and tributaries. The
smaller scale of the May flow reductions would have also contributed to the absence of
green sturgeon in stranding surveys, which were likely closer to the main channel areas
of the river. Conversely, the small number of green sturgeon present in the river
contributed to the lack of observed strandings. Therefore,any impacts to green sturgeon
populations as a whole would have been minor, based on the few individuals in the
impacted area and the lack of any observations in stranding surveys.
Table 8. Observed and extrapolated numbers of special status species stranded in wet
pools during the Oroville Dam Spillway incident (source: California DWR 2018b).
Life Target Species Observed Extrapolated
Stage stranded range stranded
Juvenile fall-run Chinook Salmon 3,938 26,7894 - 34,6469
Juvenile late fall-run Chinook Salmon 13 260 - 884
Juvenile spring-run Chinook Salmon 71 4817 - 5380
Juvenile winter-run Chinook Salmon 2 NA -0
Adult Chinook Salmon 2 136 - 136
Yearling hatchery CCV steelhead 19 1,289 - 1,631
Adult hatchery CCV steelhead 4 58 - 268
Fry wild CCV steelhead 1 70- 87
Yearling wild CCV steelhead 20 575 - 1,355
Adult wild CCV steelhead 10 145 - 676
Juvenile Green Sturgeon 0 NA
Adult Green Sturgeon 0 NA
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With regard to habitat quality, the Feather River downstream of Oroville Dam is
designated as critical habitat for Central Valley spring-run Chinook salmon. The spring-
run salmon typically begin migrating during March. The most likely effect to any early
migrating adults would be delayed migration as the salmon would have sought out refuge
from the turbidity (Bash et al. 2001), though the turbidity also likely impaired foraging
success (Sigler et al. 1984). The effects of the accumulation of fine sediment were also
likely seen across fish species, as it can decrease macroinvertebrate prey availability
(Colas et al. 2013). This likely also contributed to a shift in benthic invertebrates from
grazers to burrowers, which are less available as a food source for fish, and increased fish
foraging activity as a result of lower prey abundance (Suttle et al. 2004).
Decreased water quality and increased sedimentation from the spillway failure was
unlikely to directly impact adult spring-run Chinook salmon, as few would have been
expected to be in the river at the time of the initial spillway incident. As noted above,
California DWR observed stranded juvenile spring-run Chinook salmon, but did not
observe any adult spring-run Chinook salmon strandings, likely because the event
occurred before any migrating salmon reached the affected area. Fine sediment added to
the river resulted in a short-term reduced in available spawning area. However, spawning
sized gravels also would have been added and transported throughout the river
downstream of Oroville Dam, and normal flows redistributed fine sediments.
Within the days following the spillway failure, the license measured turbidity as
high as 974 NTU and total suspended solids as high as 753 milligrams per liter (mgIL) at
Auditorium Riffle in the Feather River low flow channel. California DWR monitored
turbidity and total suspended solids throughout its emergency response, and it reported
that turbidity fell to and remained below 20 NTUs by April 1, 2017. Accordingly,
elevated turbidity and sedimentation also affected survival rates among California Central
Valley DPS steelhead egg, fry, and larval fish. Prolonged sedimentation effects also have
the potential to alter spawning areas downstream of the dam. These negative impacts
have been mitigated to some extent, by the additional steelhead yearling stocking in
2018. Nonetheless, it is unclear whether there was a net gain or loss in spawning and
rearing habitat in the Feather River, without actual observations.
6.8.3 Staff Recommendations
Commission staff initiated formal consultation with the FWS on August 14, 2018
regarding effects to the valley elderberry longhorn beetle from the response actions. By
letter dated September 10, 2018, the FWS concurred with the Commission's
determination that the emergency actions related to the spillway failure may have
affected, but did not likely adversely affect valley elderberry longhorn beetle. The FWS
did not require any additional conditions to its determination. The Commission also
initiated formal emergency consultation with the NMFS on July 5, 2018, regarding
impacts to California Central Valley DPS steelhead, Central Valley DPS spring-run
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Chinook salmon, and Southern DPS North American green sturgeon. Commission staff
anticipates that consultation with NMFS will result in additional mitigation measures;
however, these measures have not yet been determined and cannot therefore be discussed
in the EA. If the Commission approves the proposed response and recovery actions, it
should require the California DWR to comply with any measures recommended by the
agencies for the protection of the various species. California DWR should also be
required to provide a schedule for implementing any of these agency conditions, once
they have been issued.
Commission staff finds that the proposed actions may affect, but are not likely to
adversely affect the valley elderberry longhorn beetle. The locations chosen for the
relocated elderberry shrubs are existing riparian habitats where known clumps of
elderberry shrubs exist. While there were direct impacts to the relocated elderberry
shrubs individually at the time of transplantation, it is not likely that the valley elderberry
longhorn beetle species were affected given the isolation of the plants, their location in a
non-riparian habitat, and the lack of exist holes. California DWR's use of buffer zones,
coordinating work where feasible outside of the flight season of the valley elderberry
longhorn beetle, measures will assist in reducing the likelihood and/or mitigate for any
additional impacts.
Staff also agrees with California DWR's proposal to create an Elderberry
Relocation Plan. The creation and implementation of the plan will effectively protect
elderberry shrubs and any valley elderberry longhorn beetles located within the response
and recovery areas and those potentially located elsewhere within the project boundary.
California DWR should review the FWS's Valley Elderberry Longhorn Beetle
Conservation Guidelines (FWS 1999) and consult with the FWS, prior to submitting the
plan for Commission approval.
Commission staff finds that the response and recovery actions adversely affected
California Central Valley DPS steelhead and Central Valley DPS spring-run Chinook
salmon. Staff also finds that the above actions are not likely to have adversely affected
the southern DPS North American green sturgeon. However, many of the effects to
federally-listed fish can be offset by mitigating actions. The California DFW, in
coordination with California DWR, increased its fish stocking numbers in to offset the
hatchery fish lost during the incident and installed habitat improvements in the lower
Feather River. However, California DWR should be required to mitigate for the deficit
of 300,000 spring-run Chinook from 2017 hatchery losses. Staff recommended
mitigative actions include an increase to hatchery production in a subsequent year, habitat
improvements, or capital investment in fishery projects.
Staff recommends the California DWR prepare a plan and schedule, in
consultation with the California DFW, FWS and NMFS, to conduct a habitat survey in
the lower Feather River to determine whether the sediment loading that occurred as a
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result of the event and emergency response, had long-term effect on the river substrate.
The survey should document changes in the availability of spawning and rearing habitat,
and to determine whether additional mitigation is necessary. As such, the survey will
better inform salmonid and sturgeon management actions in the future, further mitigate
for fish losses at the hatchery, to offset any fish losses from stranding during the recovery
efforts. The plan should also be combined with the monitoring elements discussed in
section 6.3-Geology and Soil Resources and section 6.6-Fisheries and Other Aquatic
Resources.
6.9 Cultural and Historic Resources
6.9.1 Affected Environment
Cultural resources are defined as prehistoric and historic-era archaeological sites,
Traditional Cultural Properties, sites of religious and cultural significance, and
architectural properties (e.g., buildings, dams, and structures). This definition includes
historic properties as defined by the NHPA. The initial APE for the undertaking includes
prehistoric and historic archaeological resources, ethnographic and ethnohistoric
resources, and historic structures located entirely within the existing project boundary and
within the overall geographic scope of this EA. It includes: areas upstream of, adjacent
to, and downstream of Oroville Dam (including a portion of Lake Oroville located
approximately 0.5 miles upstream of Oroville Dam); Oroville Dam and adjacent damaged
areas and project features; and the segmentof the Feather River (Thermalito Diversion
Pool) extending downstream from the dam to the Thermalito Diversion Dam, Thermalito
Power Canal, and Fish Barrier Dam. The APE for the undertaking has been expanded
twice to include six recreation sites and additional acreage within the OWA, all of which
are located within the existing project boundary.
On February 8, 2017, the day after erosion was observed on the main spillway,
California DWR began working to identify known cultural resources situated in close
proximity to the spillway and its potential overflow area. Data from the baseline cultural
resources surveys completed by the California DWR as part of the Oroville facilities
relicensing process were used for this task and later, to complete pre-construction
conditions assessments. Review of the data revealed 17 previously recorded
archaeological sites or features in the vicinity. Five prehistoric sites were directly
downhill from the emergency spillway. Two of the sites were bedrock mortars; the other
three were dual-component occupation sites first recorded in the 1960s and updated with
additional information during the 2002 relicensing surveys. California DWR prepared a
map showing sensitive areas to be avoided to guide decisions in planning access roads
and other ground-disturbing activities. California DWR archaeologists used the map to
find and flag known cultural resources for avoidance. When water flowed over the
emergency spillway for the first time in the history of the reservoir on February 11, 2017,
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severe erosion occurred downslope and crews with heavy equipment worked 24 hours a
day to repair damage caused by the runoff.
Due to safety concerns, California DWR's archaeologists were not able to access
the APE until February 19, 2017. The initial fieldwork consisted of relocating previously
recorded sites on the hillside below the emergency spillway, and along Burma Road to
assess whether the release of water over the emergency spillway caused any damage to or
loss of known archaeological sites. All previously recorded sites were found, including
sites situated on the hillside in the direct path of the water release. During the field visits,
the sites were flagged with caution tape. The tape was replaced later with barbed wire
fencing or K-rail. California DWR then began identifying potentially-affected sites by
clearing areas for stock pile locations and installation of temporary shoofly transmission
lines. Archaeological village and occupation sites were given the highest priority for
protection among recorded cultural resources.
California DWR hired consulting archaeologists, who arrived on March 14, 2017,
to assist them and conduct intensive pedestrian surveys throughout the APE for various
activities related to the undertaking. During the response period, the surveys occurred
either prior to, or shortly after the commencement of work in a given location to confirm
the presence or absence of prehistoric and historic-era archaeological sites, multi-
component sites, and historic-era structures. Locations of recovery period activities were
surveyed ahead of any work. Pre-construction condition documentation included
relocating and photographing previously identified features, recording existing natural or
construction related impacts, updating site forms for each previously recorded resource,
and recording new site forms for newly discovered resources.
All surveys were conducted under the supervision of archaeologists meeting the
Secretary of the Interior's Professional Qualifications Standards for Archaeology. Estom
Yumeka Maidu Tribe (Enterprise Rancheria) representatives were present during most of
the surveys. The intensive pedestrian surveys included walking the ground surface in
systematic parallel transects spaced at no greater than 20 meters apart and using Global
Positioning System equipment to collect field data. Future surveys for ongoing recovery
work would be conducted in a similar manner.
California DWR archaeologists screened proposed work activities to determine
when construction monitoring was needed. Activities involving ground disturbance in
sediment not obviously disturbed by modern activities or involving ground disturbance
near recorded cultural resources were monitored. Enterprise Rancheria representatives
accompanied California DWR and consultant archaeologists during monitoring activities.
Typically monitored work activities included grading, cutting, geotechnical borings,
mechanized vegetation removal, crane pad construction, and transmission line and tower
wreck outs. California DWR would conduct construction monitoring for future recovery
work when needed.
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Existing historical structures associated with the Oroville facilities include the
dams, powerplants, reservoirs, and canals associated with the hydroelectric facilities,
along with the Lake Oroville Visitors Center, the Feather River Fish Hatchery, and the
California DWR's Oroville Field Division facility on Glen Drive. Two of these
resources, Oroville Dam and the Hyatt Pumping-Generating Plant, appear to be eligible
for inclusion in the NRHP as individual properties and they, along with 12 additional
facilities, are all considered contributing elements to a proposed Oroville Division
Historic District under criteria A and C, as defined in NRHP. Elements of the built
environment not directly associated with the hydroelectric facilities, such as
campgrounds, marinas, roads, and trails, were built following construction of the
hydroelectric system. No structures located within the APE have been formally
determined to be historic properties, including those associated with the Oroville
facilities. However, all historic resources within the APE were treated as NRHP-eligible
for all response and recovery activities performed as part of the undertaking.
Documented cultural resources within the APE consist mostly of resources
identified during relicensing studies. However, new discoveries have been made during
recent surveys, especially following the clearing of vegetation. Based on the review of
the previous studies and the results of fieldwork conducted following the spillway
incident, over 200 cultural resources have been identified within the APE; a little more
than half of which, fall within identified project components.
The existing resource types include prehistoric sites, prehistoric isolates, historic
sites, multicomponent sites, built environment features, historic districts, and a tribal
resource. Several effects to sites that predate the undertaking were noted; these are either
from earlier construction or maintenance activities in the APE or through damage done
during the water releases. These effects come mostly from grading and dozing access
roads, pedestrian trails for the construction and maintenance projects, and substantial
erosion, including cuts deep into underlying bedrock from the water releases. Ten
previously recorded sites were found to no longer exist, due to adverse effects that have
occurred over the past 50 or so years from the construction of the dam, erosion, or other
means before the spillway incident.
There have also been unanticipated discoveries, including site OPL-BD-FEA-015,
•
described as an alignment of stacked rock and a lumber flume. California reported the
unanticipated discovery to the PA parties on August 31, 2017, which the California
SHPO acknowledged the following day. A month earlier, on July 28, 2017, the
California DWR reported the discovery of Oroville 13, a bedrock mortar, to the PA
parties. These finds were discussed in the EA and Commission order for the permanent
transmission line reroute. An isolated bowl mortar in rock fill was also discovered on
May 9, 2018 near Oroville Dam during construction efforts near the main spillway.
California DWR notified the PA parties by electronic message, which included a report,
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on May 11, 2018. The California SHPO provided initial comments on the discovery in a
May 14, 2018 letter to California DWR. California DWR had stopped work in the area
following the discovery, but resumed activities after it was characterized in the field. In
consultation with the Enterprise Rancheria, the resource was collected by an
archaeologist and tribal monitor and placed in a secure facility for future repatriation
following the conclusion of construction. Based on a review of the resource, California
DWR recommended that it not be eligible for listing in the National Register on the basis
that it is not associated with any events or persons; is not an exceptional or unique
example of its type; and is a commonly found artifact. We concurred with that
determination of eligibility by letter to the California SHPO dated August 8, 2018. The
California SHPO concurred with our determination in a letter to the Commission dated
August 14, 2018.
Table 9 provides a tally of the individual resources across the project components.
It should be noted that some resources exist within areas where project components
overlap. As a result, adding up the resources by component produces an inflated number
of resources. Below is a breakdown of the distribution of resources within various
project components:
Table 9. Tally of Resource Types within Project
Components Number
Prehistoric 18
Historic 81
Multicomponent 11
Tribal 1
Built Environment 6
Total 117
• Burma Road Improvements -- There are 40 known resources associated with
the Burma Road component of the project. They include prehistoric resources,
historic resources, tribal resources, and built environment features. The
historic-era materials likely span from the 1850s and 60s to the late historic era
(1950s-1960s).
• Dredging— There are 18 known resources associated with the Dredging
component of the project. They include prehistoric resources, historic
resources, and tribal resources.
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• Emergency Spillway Initial Water Release— There are seven known resources
associated with the Emergency Spillway Initial Water Release component of
the project. These resources consist of prehistoric resources, historic
resources, and built environment features.
• Emergency Spillway Improvements— There are 11 known resources associated
with the Emergency Spillway Improvements component of the project. These
resources consist of prehistoric resources, historic resources, and built
environment features.
• Erosion and Sediment Control—There are 33 known resources associated with
the Erosion and Sediment Control component of the project. These resources
consist of prehistoric resources and historic resources.
• Boundary Fence—There are 20.known resources associated with the Boundary
Fence component of the project. These resources consist of prehistoric and
historic resources.
• Fiber Optic and 13.8-kV Powerline—There are 21 known resources associated
with the Fiber Optic and 13.8-kV Powerline component of the project. These
resources include prehistoric resources, historic resources, and built
environment features. This component follows the alignment of the Western
Pacific Railroad grade and terminates at the Hyatt Power Plant Switchyard.
• 230-kV Powerlines Eagle Nest—Four trees chosen for surrogate eagle nest
structure installations are located within or near three known historic-era
resources.
• PG&E Shoofly Powerline— There are eight known resources within the
footprint of the PG&E Shoofly component of the project. These resources are
all from the historic era.
• California DWR's Shoofly Powerline —There are three known resources
associated with the California DWR's Shoofly Powerline component of the
project. These resources include prehistoric and historic resources.
• California DWR's Lattice Tower Wreck Out— There are three known historic
resources within the footprint of the Lattice Tower Wreck Out component of
the project.
• Spillway Reconstruction— There are 20 known resources associated with the
footprint of the Spillway Reconstruction component of the project. These
resources include prehistoric resources, historic resources, and built
environment features.
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• Spoils Piles — There are three known historic resources within the footprint of
the Spoils Piles component of the project.
6.9.2 Environmental Effects
As described above, the work performed by California DWR to stabilize and
remediate the damaged spillway facilities broadly falls into two actions: initial response
and recovery. Most of the construction activity for both actions occurred on the slopes
adjacent to the spillways. The initial response actions include: main spillway releases;
construction of access roads, stockpiles and staging areas; stabilization of the main and
emergency spillways; in-water and land-based debris removal; and installation of
emergency shoofly powerlines for both the California DWR and PG&E lines. The
recovery actions include reconstruction of the main and emergency spillways (with the
addition of a secant pile wall); continued in-water debris removal; permanent reroute of
both the California DWR and PG&E primary transmission lines (previously analyzed in
separate EAs prepared by the Commission in August 2017); wreck-outs of California
DWR and PG&E shoofly lines and original transmission line lattice towers; installation
of a 13.8-kV powerline and associated fiber optic communication system; repair of radial
gates; improvements to access roads, including Burma Road; construction of work pads,
staging areas and spoils sites; and activities at the Feather River Fish Hatchery.
Effects to cultural resources from the initial response and the subsequent ongoing
recovery operations have varied depending on the activity. The initial response consisted
of clearing vegetation from the sides of the main spillway and downstream of the
emergency spillway for better observation of spillway conditions, and to remove trees
and other debris that could wash down and accumulate against the Thermalito Diversion
Dam. Roads were also excavated and graded to allow access to various parts of the
spillways, and to the Thermalito Diversion Dam staging area. The access road to the
spillway recreation area was washed out when the emergency spillway was used for the
first time in February 2017. The parking lot is now a command center for the
undertaking, while Burma Road and sections of the Dan Beebe and Brad Freeman Trails
have become haul routes.
As the initial response phase transitioned to the recovery phase, the potential for
adverse effects to cultural resources increased. In addition to the grading of numerous
access and haul roads to facilitate construction, there was active excavation and blasting
of soil and rock to stabilize the lower chute of the main spillway.' Other landscape-
altering activities included tree and vegetation removal, rock crushing operations to
produce aggregate for concrete, the building of cement batch plants, and the creation of
soil and rock stockpiles from rock and sediment dredged from the Thermalito Diversion
Pool.
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The project components within the APE that could affect cultural resources are
described below. Please note that the Area of Direct Impact for some of these activities
overlap.
• Burma Road Improvements — Overall this includes the widening of, and
improvements to, Burma Road along the north side of the Thermalito Diversion
Pool. Specifically, it includes: clearing and grubbing vegetation; cutting,
filling, and grading; installation of box culverts; installation and replacement of
metal pipe culverts; road compaction; placement of aggregate base road surface;
and paving with asphalt. There was also new construction to accommodate
large vehicles and large loads on Power Canal Road and Cherokee Road, which
included paving and additional widening. Of the 40 known resources within the
Burma Road component, five historic-era resources and two resources, with
each having prehistoric and historic-era elements, have been directly affected
and three historic-era resources, one prehistoric resource, and one resource with
both prehistoric and historic-era elements have been indirectly affected. The
direct effects include damage from culvert installations, widening of Burma
Road, creation of a spoils pile and utility terrain vehicle (UTV) tire tracks.
There were also indirect adverse effects from fences crossing over linear
features, clearing and grubbing activities, and wave action erosion.
• Dredging—This component includes the removal of sediment from the
Thermalito Diversion Pool by barge-mounted excavators. The dredged material
is then off-loaded at barge landings and transferred to spoil piles locations set
up within the APE. The ability for the Thermalito Diversion Pool to convey
adequate flow may require continued in-water debris removal. Of the 18
known resources within.the Dredging component, one historic-era resource, a
fence, was directly affected and no longer exists. Indirect, minor, adverse
effects from inundation, wave action erosion, or the crossing of a fence,
affected one prehistoric resource, one historic-era resource, and two resources
with both prehistoric and historic-era elements.
• Emergency Spillway Initial Water Release —This component includes the
scouring of the hillside due to the initial release of water over the Emergency
Spillway, which was followed by deliberate vegetation removal. Of the seven
known resources within the Emergency Spillway Initial Water Release
component, one historic-era resource, a fence, was directly affected and no
longer exists (the same fence listed above under Dredging). A resource with
both prehistoric and historic-era elements was also severely eroded. Another
historic-era resource was affected through the conversion of a haul road. In
addition, the slope below the emergency spillway was eroded.
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• Emergency Spillway Improvements— This component pertains to the
stabilization of emergency spillway area. Specifically, it involves: clearing and
grubbing of vegetation; cutting and grading; creation of new access roads;
geotechnical testing; staging areas and work pads; placement of rock and
concrete on slope immediately below spillway to armor the slope; and
installation of a secant cut-off wall, crest cut-off wall and splash pad. Of the 11
known resources within the Emergency Spillway Improvements component,
three historic-era resources were directly affected. A segment of one of those
resources, a fence, was destroyed by a spoil pile. The other two, a prospect pit
and a stone dam, were also destroyed. There were also indirect, minor effects
caused by clearing and grubbing occurred in the vicinity of two prehistoric sites
and one historic-era site.
• Erosion and Sediment Control — This involves stabilization of on-site sediment
primarily on the hillside adjacent to the main spillway. The work consisted of
placement of hydroseed,.hydromulch, mulch, and fiber rolls; installation of
concrete aggregate base and sediment traps at laydown, parking, and crane pad
areas; creation of drainage swales; regrading roads and installation of V-ditches
and compacted berms adjacent to roads; and culvert installation and
maintenance. Of the 33 known resources within the Erosion and Sediment
Control component, 14 historic-era resources, including roads, ditches and
fences, and one resource with both prehistoric and historic-era elements, have
been directly affected and either are heavily damaged, some from conversion
into haul roads, or no longer exist. There were also indirect, minor effects
caused by clearing and grubbing in the vicinity of two prehistoric resources and
one historic-era feature.
• Boundary Fence—This includes the installation of a fence line along the
property boundary above Burma Road. The fencing consists of three to five-
strand barbed-wire with T-post and wood post supports. Activities conducted to
install the fence included vegetation removal and the use of the existing,
unimproved dirt paths by all-terrain vehicles. Of the 20 known resources within
the Boundary Fence component, three historic era resources and one resource
with both prehistoric and historic-era elements have been directly affected with
portions of these resources damaged by road widening, a spoils pile and UTV
tires. Indirect, minor effects occurred to five historic-era resources, two
resources with both prehistoric and historic-era elements, and one prehistoric
site, mostly from the construction of the fence.
• Fiber Optic and 13.8-kV Powerline—There was an installation of a new
underground fiber optic line and a new 13.8-kV electric transmission line, with
both overhead and underground components. The work consisted of clearing
and grubbing vegetation; grading for associated access roads; trenching for
91 •
underground lines; installation of conduit; and stringing of fiber optic cable on
230-kV transmission structures. Of the 21 known resources within the footprint
of the Fiber Optic and 13.8-kV Powerline component, future construction is
likely to directly, adversely affect seven historic-era resources, one prehistoric
resource, and one resource with both prehistoric and historic-era elements.
Overall, 17 historic-era resources, three resources with both prehistoric and
historic-era elements, and one prehistoric resource, could be affected, either
directly or indirectly, by future construction of this component.
• 230-kV Powerlines Eagle Nest—There were four trees chosen for surrogate
nest structure installations after an eagle nest was identified and removed by
permit from a felled hazard tree. The work involved carrying equipment and
materials to the selected trees and climbing the trees to install materials. The
three known historic-era resources surrounding and/or near the trees were
avoided or minimally affected by walking in to get to the trees.
• PG&E Shoofly Powerline— This includes installation and removal of a PG&E-
owned temporary electric transmission line. Specifically, the work consists of
clearing and grubbing vegetation; grading for associated access roads; cutting
and grading for transmission tower construction; transmission tower
construction (including excavation for piers), line stringing; and the removal of
existing transmission lines and towers. Of the eight known resources within the
PG&E Shoofly component, six of them were directly and adversely affected..
The other two were avoided. All are historic-era resources and reflect the
transportation, settlement and mining themes.
• California DWR Shoofly Powerline—This includes the installation and removal
of the California DWR-owned temporary electric transmission line. The work
is the same as described above for the PG&E Shoofly Powerline. Of the three
known resources within the California DWR Shoofly Powerline component, the
two historic-era fence lines have been directly and adversely affected by the
work. Effects to a prehistoric resource were avoided.
• California DWR Lattice Tower Wreck Out— This involves the removal of the
original California DWR-owned lattice transmission towers near the main
spillway. The work involved is the same as that for PG&E Shoofly Powerline.
Of the three known resources within the Lattice Tower Wreck Out component,
the historic-era fence line, and one of the two roads, have been directly and
adversely affected. The other road may have been affected by the work,
however its current condition is unknown.
• Spillway Reconstruction—This includes the demolition and reconstruction, in
the same location, of the main Spillway. The work includes blasting,
demolition and removal of existing concrete spillway; geotechnical testing; •
92
clearing and grubbing vegetation; cutting, filling, and grading for access roads,
staging areas, and concrete batch plants; quarrying aggregate for RCC, concrete
backing and other uses; placement of new concrete and associated
reinforcement; and establishment of temporary ancillary facilities (e.g.,
dewatering, etc.). Additionally, the radial gates on both the FCO Spillway and
the Thermalito Diversion Dam were damaged. Both sets of radial gates would
be returned to their original functions. For the gates, the work involves the
repair and replacement of hardware. Of the 20 known resources within the
Spillway Reconstruction component, nine historic-era resources, including the
FCO Spillway, and one resource with both prehistoric and historic-era elements,
have been directly and adversely affected or no longer exist due to construction
activities noted above. There was also an indirect, minor effect to one
prehistoric site from clearing and grubbing.
• Spoil Piles — This includes the placement of dredged sediment from the
Thermalito Diversion Pool in large piles and involves clearing and grubbing of
vegetation; cutting, filling, and grading for initial site; and placement of
dredged sediment. All three of the known historic-era resources within the
Spoil Piles component have been directly and adversely affected. A portion of
the fence line, the prospect pit, and the road no longer exist, due to the creation
of a spoils pile.
Avoidance and Minimization, and Mitigation
Avoidance is generally the preferred method for effects to cultural resources. The
California DWR has been coordinating directly with the California SHPO, Commission
staff, FEMA, California Office of Emergency Services, and local Native American tribes
to address potential effects to cultural resources and to ensure that avoidance of cultural
resources is implemented whenever possible.
Additionally, measures to minimize effects to cultural resources have been
implemented throughout the life of the undertaking. These measures include physical
barriers, such as barbed wire fencing, K-rail, and caution tape; the use of hand tools and
barring of mechanical clearing and grubbing within 50 feet of cultural resources;
coordination with contractors to identify work staging and set up areas that avoid cultural
resources; and the designation of Environmentally Sensitive Areas that are monitored by
both archaeologists and tribal monitors when construction activities occur nearby. Other
measures include the implementation of a monitoring and discovery plan; preparation of
detailed, updated site forms with photographs, archival data and feature drawings;
conducting a post-construction condition assessment of the sites; and implementation of a
data recovery plan in the event that archaeological or tribal monitors identify
information-bearing deposits. These protective measures are consistent with the Historic
93
Property Management Plan (HPMP) that was developed as part of the compliance with
section 106 of the NHPA for the relicensing of the Oroville Facilities. Prior to most
ground disturbance activities, training was provided to construction personnel to provide
education on the sensitivity of the APE, the kinds of resources that might be encountered,
and the appropriate response to the inadvertent discovery of cultural resources.
The California DWR conducted daily construction monitoring throughout the
summer months of 2017 for activities that included ground disturbance in sediment not
obviously disturbed by modern activities, or, activities including ground disturbance near
recorded cultural resources. The California DWR would continue construction
monitoring on an as-needed basis for future work. Also, tribal monitors from Enterprise
Rancheria accompanied consultant archaeologists during monitoring activities, with
oversight by a California DWR archaeologist. The California DWR and tribal
representatives monitored work that included grading, cutting, geotechnical borings,
mechanized vegetation removal, transmission line tower pad construction, and
transmission line pull areas.
Overall, California DWR -implemented measures to lessen or avoid effects to
cultural resources fall under several broad categories:
• Grading--This work involved leveling and smoothing of the ground surface
using heavy equipment and was conducted during road widening and staging
area preparation activities. Excess soils either remain on-site as fill or are
transported elsewhere to be used or stored. The California DWR had
archaeological and tribal monitors present during grading at any area
determined to be sensitive for containing cultural resources and flagged or
fenced off known cultural resources to keep equipment and construction
personnel away from the resources.
• Vegetation Removal—This included the cutting of brush and trees, followed by
stump removal. The vegetation was then crane-lifted out or dragged away by a
backhoe, bulldozer, or bobcat and either stored nearby or trucked elsewhere
within the APE. To avoid effects to cultural resources, the California DWR had
archaeological and tribal monitors present during vegetation cutting and
clearing in areas where heavy equipment or clearing crews were likely to
encounter cultural resources. Also, hand clearing was prescribed for locations
near known cultural resources, which were fenced off or flagged to keep
equipment and construction personnel away from the resources.
• Placement of Fill Material —This included placement of fill quarried from other
areas of the APE or dredged from the Thermalito Diversion Pool directly below
the main spillway. The fill was used for the repair of flood damage and erosion,
to level areas out for driving or staging, and to backfill construction. Large
94
quantities of fill material were temporarily stored in the APE for anticipated
repairs. The California DWR had archaeological and tribal monitors present
during the quarrying of materials when in sediment, but not when quarrying
bedrock. Additionally, monitoring took place during the placement of fill at
any area determined to be sensitive for containing cultural resources. Dredging
and loading operations were not monitored. Known cultural resources were
fenced off or flagged to keep equipment and construction personnel away from
the resources.
• Construction-This included installation of infrastructure for the emergency
spillway and main spillway reconstruction. The work usually involved some
form of ground disturbance, such as preparing building pads, drilling for
footings, or the cutting of slopes for drainage. The California DWR had
archaeological and tribal monitors present during all ground disturbing activities
when they occurred within soils, but not when quarrying bedrock. Additionally,
monitoring took place during the placement of fill at any area determined to be
sensitive for containing cultural resources. The California DWR fenced off or
flagged known cultural resources to keep equipment and construction personnel
away from the resources.
• Multiple Effects -Pre-project effects to sites combined with erosion from the
spillway release and rapid post-event recovery and stabilization efforts in some
cases resulted in the destruction of or severe damage to cultural sites. The
California DWR noted prior damage to sites and archaeological and tribal
monitors were present during all ground disturbing activities occurring within
soils. Known cultural resources were fenced off or flagged to keep equipment
and construction personnel away from the resources.
• Partial or complete erosion -Both known and undiscovered sites may have been
adversely affected after the water release that led to the main spillway failure.
The landscape was stripped down to bedrock and in many places erosion cut
several feet into the bedrock. Existing drainages were scoured and the material
transported into the Thermalito Diversion Pool. Previously recorded sites that
were lost were recorded as such, and no further action was taken at these
locations. Additionally, partially damaged sites were assessed and fenced or
flagged and archaeological and tribal monitors were present during all earth-
moving activities at these locations.
• VehicIe tracks -Operating heavy equipment over cultural resources sometimes
created impacts to individual features or soil disturbance, depending on the
moisture content of the soil and the type of equipment. The California DWR
fenced off or flagged known cultural resources to keep equipment and
95
construction personnel away from the resources. Archaeological and tribal
monitors were present during ground disturbing activities that occurred within
soils.
Findings of Effect under Section 106
Pursuant to the terms of the PA, California DWR submits effect recommendations
for historic properties to the Commission, who is responsible for making all findings of
effect and for the resolution of adverse effects and disputes. The PA may be amended to
include the resolution of effects to resources prior to its execution. The potential for
adverse effects to cultural resources from the implementation of the above component
activities was assessed in the context of each component's Area of Direct Impact. Project
impacts, as well as pre-project impacts, were noted during site assessments conducted
prior to construction. Additionally, California DWR.plans to conduct post-construction
assessments as well.
In accordance with the PA, all cultural resources in the APE not previously
evaluated for NRHP-eligibility are assumed NRHP-eligible for the purposes of the
undertaking. Some resources may also be contributing elements to one of two proposed
historic districts --the Forks of the Feather River Historic District and the Oroville
Division of the State Water Project Historic District. One historic-era site that previously
did not appear to be a contributor to the Forks of the Feather River Historic District, P-
04-001926, was re-evaluated during the current project as part of a finding of effect effort
following project impacts. The resource, a dirt road, was not found to be individually
eligible for the NRHP or a contributor to the historic district. On October 17, 2017, the
California SHPO concurred with the Commission that the resource was not eligible and
on October 23, 2017, Commission staff issued a finding of no historic properties affected
for the creation of a rock quarry. Another historic-era resource, site P-04-002609, was
previously identified as a contributor to the Forks of the Feather River Historic District,
but a re-evaluation concluded that the resource was not eligible for the NRHP
individually or as a contributor to the historic district, as it did not meet NRHP criteria.
The determination allowed Commission staff to make a finding of no historic properties
affected by the removal of an existing transmission tower by letter dated November 7,
2017.
Additionally, California DWR prepared finding of effect documents for two built-
environment elements of the proposed Oroville Division of the State Water Project
Historic District, the Spillway (filed with the Commission on July 21, 2017), and the
Radial Gates (filed on July 26, 2017). In both cases, California DWR determined that
project would not result in an adverse effect or substantial adverse change to any
character-defining features or contributing elements. The Commission concurred with
California DWR's determination in a letter dated August 29, 2017, however the effects of
the work would be re-assessed if there are significant design changes. To date, there
96
have not been any significant design changes. California DWR also recommended a
finding of no adverse effect on the FCO Spillway for the construction of a RCC platform,
filed with the Commission on November 3, 2017. Commission staff agreed with
California DWR's no adverse effect finding for the RCC platform by letter dated
December 1, 2017. On December 4, 2017, California DWR filed a recommendation for a
finding of no adverse effect for the installation of platforms for alternative eagle nest
locations. Commission staff concurred with California DWR's finding by letter dated
December 7, 2017. On December 15, 2017, California DWR filed a recommendation for
a finding of no adverse effect for the conversion of a temporary drainage crossing near
Tower 4 of the project's existing 230-kV electrical transmission Iine to a permanent
crossing. Commission staff concurred with California DWR's finding by letter dated
February 5, 2018. On March 6, 2018, California DWR filed a recommendation of no
adverse effect for the removal of a storage building located on the left side of the Oroville
spillway at the western end of Bone Yard Road. In a letter dated April 6, 2018,
Commission staff concurred with California DWR's finding since the storage building
did not meet the age requirements for listing in the National Register of Historic Places,
nor did it meet any of the criteria for listing of resources less than 50 years old. On June
15, 2018, California DWR filed a recommendation for a finding of no adverse effect for
the installation of two temporary air quality monitoring stations, one of which would be
installed in a portion of a previously recorded archaeological resource. Based on the
protective measures proposed by California DWR, Commission staff concurred with
California DWR's finding by letter dated August 8, 2018. On August 1, 2018, California
filed a recommendation for a finding of no adverse effect for two previously-recorded
cultural resources and one new cultural resource located in or adjacent to areas affected
by the removal of temporary transmission towers installed during the spillway incident.
Based on the protective measures proposed by California DWR, Commission staff
concurred with California DWR's finding by letter dated August 28, 2018.
Prior to implementation of the PA, the California DWR-owned transmission line
reroute work had a finding of effect documentation prepared by California DWR. By a
letter dated June 16, 2017, the California SHPO did not object to California DWR's
finding of no adverse effect for the work.
The combination of effects to site CA-BUT-1105H (a large mining/habitation site)
from recent and proposed future construction would likely constitute an adverse effect to
site CA-BUT-1105H. California DWR is currently preparing a finding of effect for
consultation with the PA parties. Additionally, California DWR intends to prepare
finding of effect documents for new project components before the end of calendar year
2018. Within these documents, California DWR proposed mitigation measures would be
included, as necessary, based on the findings.
97
6.9.3 Staff Recommendations
As discussed above, there were several cultural sites directly and adversely
affected by erosion from the spillway release and the subsequent response and recovery
efforts. Although no mitigation for the adverse effects has been formally proposed,
California DWR has been discussing potential measures with the California SHPO and
other parties to the PA. Staff recommends that after these discussions are complete,
California DWR develop and submit a mitigation plan to the PA parties for review and
comment. California DWR should address those comments before filing the final plan
for Commission approval.
Additionally, staff recommends California DWR continue to implement measures
to avoid and minimize potential effects to cultural and historic resources during the
recovery phase of the work. These measures include avoiding known resource locations,
installing physical barriers, use of hand tools where necessary, training contractors,
designating sensitive areas, and conducting monitoring by both archaeologists and tribal
monitors when construction activities occur near sensitive sites. Pursuant to the executed
PA, DWR should also continue consulting with the California SHPO, tribes, and other
PA parties for determinations of eligibility and findings of effect arising from the
ongoing recovery activities.
6.10 Recreation
6.10.1 Affected Environment
The project includes a variety of recreational facilities (Figure 14), with about
28,000 of the 41,540 acres within the project boundary included in the Lake Oroville
State Recreation Area. This includes all of the recreational facilities at Lake Oroville, the
Thermalito Diversion Pool, and the Thermalito Forebay. Recreation is also provided at
the Thermalito Afterbay, the OWA, and along the Feather River. Undeveloped public
land around Lake Oroville is abundant and available for general public use. However,
steep slopes are common above the Lake Oroville shoreline and generally limit public
access to afew areas.
Recreational activities at Lake Oroville include high- and low-speed boating, non-
motorized boating, fishing, swimming, bicycling, equestrian use, hiking, hunting, bird
watching, and developed and primitive camping. In addition to the license-required
recreation, the project includes visitor information areas providing cultural and project
facility displays. License-required recreation sites/facilities at the Feather River Project
include (Table 10):52
52 See Table 43 and Figure 18 in the FEIS at pages 207-213 for a complete listing
of facilities and amenities (FERC 2007).
98
Table 10. Summary of license-required recreation facilities
Lake Oroville Visitors Center Bidwell Canyon Boat Ramp and Day Use Area
Lime Saddle Boat Ramp and Day Use Area Loafer Creek Boat Ramp and Day Use Area
Oroville Dam Day Use Area Spillway Boat Ramp and Day Use Area
Enterprise Boat Ramp Thermalito Afterbay Boat Launch and Day Use
Areas
North Thermalito Forebay Recreation Area South Thermalito Forebay Recreation Area
Thermalito Diversion Pool Day Use Area The Oroville Wildlife Area Afterbay outlet
camping area
Car-top Boat Launch Ramps are located at: Dark Canyon, Foreman Creek, Nelson Bar,
Stringtown, and Vinton Gulch
Campgrounds are located at: Bidwell Canyon, Lime Saddle,Loafer Creek, North Thermalito
Forebay RV, and Area Afterbay outlet camping area
Float In and Boat in Campsites and other Miscellaneous Day Use Areas
Trails (hiking, biking, equestrian): Brad Freeman Trail, Dan Beebe Trail,Kelly Ridge Trail, and
Saddle Dam Trailhead
99
CI
WEST • �\UPPER NORTH
BRANCH 7: FORK
Nelson Bar CT BR • Dark Canyon r
/ CTBR .
Lime Saddle 'J: i l CD
Campground -- . :- ‘S ,jy
Marina1 :
Vinton Gulch .�"
'
CT BR I;
Goat Ranch \.;; LOWER %'
Boat•in • ,• NORTH �,
Campground t`";:;. - FORK MIDDLE
70 I •s FORK
Bloomer Boat•intKr +'r r Foreman l
,,: ;
Cam unds `. _• - —Creek Boat-In
(Point Knoll, Campground
Cove,Group) - -f CT BR
• North Thermalito ..1—j••`IPN
Forebay`En Route" • lS '`i 1 �.
RV Campground
99 DUA18RARuatic LakeOroviue OROIUE
Center Visitors Center tt1ARd Craig Saddle Boat-in Campground
BASSI Stringtown
Toland Rd. South Spillway • CT BR ,
Trailhead Thermalito i DUNG •.. .. . 1 .:,.:
Forebayy ON Diversion . ,•7<.-
HMonumBRiDUA DUNS ..Pool DUA ~= '- �. •4 r SOUTH FORK
~�. Powerhouse •
Tres Vias Rd Rd.Tracheal Oro'Be ;if
Loafer Creek DUA BR Enterprise BR
Trailhead �"
"-'4:Lakeland Blvd. D.' Campground Horse
•10 •' 60 OROVILLE• Trailhead 0 Camp Group Camp
' •-. Model Aircraft Bidwell
N. 4 Flying Area 1 Feather River Canyon BR Saddle Dam
3j Fish Hatchery DUA
DM/Trailhead
Wilbur•�• \ Campground
�Rd B\ ` "-OWA:HQ Entrance
• Larkin Rd.CT BR
441‘,
�4 '•'♦ • OWA:Pacific Heights Rd.Entrance LEGEND
East i\` OWA Vance Ave Entrance BR=Boat ramp
Hamilton Rd. CT=Car-top boat ramp
Trailhead
. DUA=Day-use area
OWA •----OWA lighway 70 Entrance HO=Headquarters
Afterbay Outlet OWA=Oroville Wildlife Area
Camping • • Recreation site
Areas/BR
OWA:Palm
State Highway
Ave.Entrance FERC project boundary
\7Oroville WildlireArea
I j Water body
ilD
0 1 2 4
Scale in miles N
Figure 14. Lake Oroville Recreational Sites and Facilities (FERC 2007)
100
Project recreation sites directly affected by the February 7, 2017 spillway
emergency include: the Spillway Boat Ramp and Day Use Area, the Oroville Dam Day
Use Area, the Thermalito Diversion Pool Day Use Area, and several trails. The
preexisting conditions of these sites are further described below.
Spillway Boat Ramp and Day Use Area
The Spillway Boat Ramp and Day Use Area is located adjacent to the right
abutment of the Oroville Dam. The recreation site includes two multi-lane boat ramps,
one with eight lanes used during low to medium water levels and the other with 12 lanes
used during medium to high water. The upper parking Iot includes 118 single-vehicle
parking spaces (8 are Americans with Disabilities Act accessible)53 and 350
vehicle/trailer parking spaces, 40 for self-contained recreational vehicle camping. The
main ramp allows for a maximum of 75 vehicle/trailer parking spaces. Also located at
the site are six flush toilets (two are Americans with Disabilities Act accessible), drinking
water, a fish cleaning station, and picnic sites including six tables, shade trees, and a sun
shelter. Lastly the site includes trailheads for the Brad Freeman and Dan Beebe Trails,
and access to Potter's Ravine and Potter's Point.
Oroville Dam Day Use Area
The crest of the OrovilIe Dam can be used for driving, sightseeing, walking,
jogging, bicycling, rollerblading, horseback riding, and fishing. The Oroville Dam Day
Use Area is located at the east and west ends of the dam. The east day use area includes
picnic tables, drinking water, four flush toilets (one is Americans with Disabilities Act
accessible), and parking for approximately 20 vehicles. The west day use area is only
open when water is below the sill of the spillway gates for security reasons, and includes
picnic tables. While there are approximately 400 parking spaces across the crest of the
dam (two are Americans with Disabilities Act accessible), parking has been prohibited,
due to increased security following September 11, 2001. The Upper Overlook is located
on the east side of Canyon Drive and includes an interpretive display, bench seating,
picnic tables, a shade structure, and parking for approximately 20 vehicles. Trailheads
from these day use areas include those for the Brad Freeman, Dan Beebe, and Kelly
Ridge Trails.
53 California DWR has indicated that specific recreation facilities are, or will be
constructed in accordance with the Americans with Disabilities Act design standards.
Pursuant to its license requirements, California DWR has considered the needs of persons
with disabilities. California DWR's obligation to comply with the Americans with
Disabilities Act exists independent of its project license, and the Commission has no
statutory role in implementing or enforcing the Americans with Disabilities Act as it
applies to its licensees. See 78 FERC ¶ 61,363.
101
Thermalito Diversion Pool Day Use Area
The Thermalito Diversion Pool is located below the Oroville Dam and above the
Thermalito Diversion Dam. The day use area is located along Burma Road. It is open
for fishing, non-motorized boating, trail use, and picnicking. The site includes a vault
toilet building and a gravel car-top boat launch. The Powerhouse Road Trailhead is south
of the Hyatt Power plant and connects to the Brad Freeman Trail along the south
shoreline of the Thermalito Diversion Pool. Burma Road is a corridor/trail head for the
Brad Freeman Trail, which runs along the north shoreline of the Thermalito Diversion
Pool.
Designated Trails
The Brad Freeman Trail is a multi-use trail providing recreation for hikers, bikers,
and equestrian trail riders. The Brad Freeman Trail circles the off-river Thermalito
Forebay and Thermalito Afterbay, follows the northern shore of the Thermalito Diversion
Pool, crosses the crest of the Oroville Dam, and turns back to follow the southern shore
of the Thermalito Diversion Pool. The full trail is approximately 41 miles long and is
predominantly dirt or gravel, with only a short paved section. The Dan Beebe Trail is a
14.6-mile-long multi-use trail for equestrians and hikers. The Dan Beebe Trail parallels
the southern shore of the Thermalito Diversion Pool a short distance upland from the
Brad Freeman Trail. The Kelly Ridge Trail is a non-motorized trail from Oroville Dam
area to the Bidwell Canyon Recreation Area.
6.10.2 Environmental Effects
Following the February 2017 spillway failure and during response and recovery
actions, California DWR closed or is implementing modifications to several project
recreation facilities located primarily near the Oroville Dam and around the Thermalito
Diversion Pool. Closures of specific recreation sites and facilities were implemented for
various reasons, such as damage to recreation site access roads, concern for public safety,
and for the construction required by various response and recovery actions, including:
the clearing for, and creation of roads; installation of the 13.8-kV powerline and
associated fiber optic communication system; concrete batch plants; and laydown,
staging, and miscellaneous support areas. Site closures are expected to have short-term
and but significant adverse effect on recreational activities at the project. However to
mitigate for the adverse effects, California DWR is expanding parking capacity and boat
ramp lengths at some sites to accommodate the recreation seasons during the response
period, which will provide additional recreation for a long-term beneficial effect to the
boating community. Land clearing performed during the response and recovery phases
will both directly and indirectly effect recreation sites, trails, and the user's aesthetic
experience, depending on the proximity of the clearing to the recreational amenities. The
102
impact will occur following the completion of the construction activities during the
demobilization and restoration efforts performed post recovery efforts. California DWR
has provided timeframes for which some sites may reopen, and has made commitments
towards selected restoration.
Approved Recreation Amendments
California DWR took steps to offset the negative impacts to recreation sites and
trails that were closed, and to mitigate for low water levels following the February 2017
incident by requesting to implement certain recreation improvements proposed as part of
Settlement Agreement negotiations for the relicensing proceeding, and ahead of new
license issuance.54 California DWR filed proposals on June 1, 2017, August 3, 2017, and
December 8, 2017, to amend the existing project's Recreation Plan.55 To help offset the
temporary closures of the Lake Oroville spillway facilities and the Thermalito Diversion
Pool and to account for the lower than normal pool elevation, during the emergency
response and recovery activities, California DWR proposed to implement certain
permanent recreation improvements immediately, and to provide additional recreational
capacity as soon as possible. The Commission approved California DWR's proposals by
Orders issued July 12, 2017,56 September 13, 2017,57 and February 1, 2018.58
Improvements would be made at the Lime Saddle Boat Ramp and Day Use Area,
Bidwell Canyon Boat Ramp and Day Use Area, Enterprise Boat Ramp, Saddle Dam, and
Loafer Creek Boat Ramp and Day Use Area (Figure 15). The completion of these
facilities would result in a net increase in available parking spaces and boat ramps, the
extension of existing boat ramps, improved trailheads, and improved marina access
during times of low lake levels at Lake Oroville. The addition of these facilities at Lake
Oroville will mitigate for the above described site closures and provide a long-term
beneficial effect regarding boating opportunities particularly during times of lower lake
levels, down to approximately 700 feet msl. By extending various boat launches in
spring and winter 2018, the public would have additional access to the reservoir
54 See Settlement Agreement filed on March 24, 2006, under Project No. 2100-
052.
55 Order on Revised Recreation Plan (68 FERC ¶ 61,358), issued
September 22, 1994; Order Approving Amendment to Recreation Plan
(124 FERC ¶ 62,182), issued September 10, 2008.
56 Order Amending Recreation Plan (160 FERC ¶ 62,021).
57 Order Amending Recreation Plan (160 FERC ¶ 62,226).
58 Order Amending Recreation Plan (162 FERC ¶ 62,077).
103
throughout the 2018 and 2019 recreation seasons, given the various elevations
encountered throughout the recovery efforts. Table 11 provides a listing of available boat
ramp lanes, around the lake, at specified lake elevation levels as approved by the
Commission."
Table 11. Summary of Oroville Boat Ramp Useable Lake Elevation Data
Site Name Lane Total Elevation
Lime Saddle Boat Ramp 2 900 — 702 feet msl
1 900 — 762 feet msl
1 900 — 801 feet msl
1 900 — 853 feet msl
Spillway Boat Ramp 12 900 — 816 feet msl
6 821 — 729 feet msl
2 821 — 695 feet msl
1 665 —and below
Bidwell Canyon Boat Ramp 1 900 — 850 feet msl
1 900 — 802 feet msl
5 900 — 735 feet msl
5 745 — 700 feet msl
3 717 — 660 feet msl
1 665 —and below
Loafer Creek Boat Ramp 3 900 — 800 feet msl
2 900 —775 feet msl
3 810 —700 feet msl
5 810—640 feet msl
Enterprise 2 900 —750 feet msl
California DWR Service 2 900— 730 feet msl
Area
Stringtown Car-top 1 900 — 869 feet msl
Dark Canyon Car-top 1 900 — 847 feet msl
Nelson Bar Car-top 1 900— 854 feet msl
Vinton Gulch Car-top 1 900 — 849 feet msl
Forman Creek Car-top 2 900— 730 feet msl
59 Additional lane extensions are proposed at the Bidwell Canyon and Spillway
boat ramps as part of the relicensing Settlement Agreement but these actions are pending
in the relicensing proceeding.
104
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Figure 15. Recreation Mitigation Locations (source:. California DWR 2018b)
105
Ongoing Recreation Effects
Closed Project Recreation Sites
The February 7, 2017 incident washed out the roads used to access the Spillway
Boat Ramp and Day Use Area, restricting the public's access to the site. Since that time,
California DWR has been using the parking lot associated with the boat ramp and day use
area as an emergency response command center. California DWR also constructed a
RCC Plant in the boat ramp parking lot. California DWR anticipates that the Spillway
Boat Ramp and Day Use Area would be closed for two years. Following the emergency,
California DWR also closed the Oroville Dam Overlook Day Use Area and is utilizing
the adjacent parking lots for construction staging areas. Similarly, the Thermalito
Diversion Pool Day Use Area was fully closed, and is being used as a staging area
primarily for equipment associated with dredging activities. Currently portions of the
Thermalito Diversion Pool southern shoreline are open to the public.
The closures of the recreation sites required by the incident response and recovery
actions and their utilization for purposes other than for public recreation, as described
above, will have a direct and significant effect on the physical sites and their users.
Specifically these sites have and will continue to be used solely as construction zones,
with added support buildings, trailers, and laydown areas to aid both the response and
recovery efforts. The duration of these effects are still unknown as the timing to
complete the recovery efforts continues to evolve and the reopening of individual sites
will be dependent on their proximity to the ongoing work and California DWR's ability
to and timeline for restoring them to their pre-emergency conditions. Until such time that
the sites are reopened to the public, recreationalist will be temporarily displaced and need
to locate alternative sites in the surrounding area to use.
Closed Trails and Trailheads
Sections of the Dan Beebe, Brad Freeman, Kelly Ridge, Potter's Ravine, and
Burma Road trails are closed. Several trailheads in the vicinity of the project are also
closed including, but not limited to, those located at the day use areas mentioned above,
and Potter's Ravine and Potter's Point, Powerhouse Road, Burma Road, and Lakeland
Boulevard (Figure 16). These closures will directly adversely affect the community and
visiting recreationalists in the area and will cause some to seek other opportunities at the
project and in the surrounding area. Because of this, there is the potential for crowding
on the open trails and the potential for clashes between the various trail users (i.e., hikers,
bikers, equestrians, etc.). While the negative effects will be direct on the user experience,
they will be short-term, as California DWR expects to reopen the trails once the response
construction is complete.
106
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16.
the Spillway Recreation Trails Affected by Incident (source: California DWR
2018b)
107
Effects to Recreation Outside of Response and Recovery Areas
California DWR notes that there are recreation facilities outside of the response
and recovery work areas, not directly affected or closed as a result of the Spillway
emergency, that have been impacted. Specifically, the Bidwell Canyon Boat Ramp and
Day Use Area, the Loafer Creek Boat Ramp and Day Use Area, and the Lime Saddle
Boat Ramp and Day Use Area have seen an increase in recreational use. During
Memorial Day and Independence Day 2017, these sites either reached, or were close to
reaching maximum capacity.
Sites that were directly affected by the response and recovery actions, and closed
for the duration of recovery efforts, have unintentionally compelled recreationists to use
other project and non-project recreation sites; thus increasing recreational use at those
locations that remain open. The increased use not only has the potential to overcrowd
recreation sites but has the potential to add operational and maintenance burdens on those
staffing and maintaining them. Therefore, additional indirect, moderate, adverse effects
will occur to the user recreational experience and the facilities at recreation sites that
remain open until such time that the closed sites are restored and open for public use.
6.10.3 Staff Recommendations
California DWR reports the recreation site closures to the public through various
avenues, including the California DWR's Oroville Spillway Incident webpage" as well
as on the California Department of Parks and Recreation Lake Oroville State Recreation
Area webpage." Due to the changing status of site availability, staff recommends that
California DWR continue to use the webpages to provide information to the public about
available recreation, including informing the public as it completes the recreation
improvements approved in the July 12, 2017, September 13, 2017, and February 1, 2018
Recreation Plan amendment orders. California DWR should continue to utilize and
update its website until such time that the recovery efforts are complete and all license-
required recreation is open to the public.
During the relicensing process, it was determined that recreational use at the
project was at or approaching the capacity at some of the developed recreation sites. The
closure of project recreation sites due to the spillway emergency event has had direct and
significant adverse effects on recreational opportunities in the area. For this reason, and
because the duration of the recovery work, demobilization, and potential site restoration
affecting these areas is unknown, staff recommends that California DWR monitor project
60 https://www.waterca.gov/orovillc-spillway
61 littps://www.parks.ca.govr?page__ic1=-462
108
recreation during the 2019 and 2020 recreation seasons to determine if they are
adequately meeting public needs. This monitoring, will help the California DWR
manage the changes in recreational demand and use patterns, and provide a structure to
evaluate the adequacy of project recreational facilities to meet future recreational needs.
As part of this monitoring California DWR should file reports with the
Commission no later than December 31, 2019 and December 31, 2020, with the potential
to extend the reporting requirement dependent on the recovery actions and their impact to
recreation sites post year 2019. The monitoring reports should include: 1) documentation
of the effects that the closed sites are having on the remaining project-required recreation,
for example, whether the closed sites are driving increased use of open sites at or above
use capacity, if increased use is requiring additional maintenance and how that is being
handled, any increased public safety issues, etc.; 2) a plan and schedule to mitigate for
any above-capacity recreation demand; 3) an update on the use of Burma Road; 4) an
updated timeline of when closed sites may begin to be restored and opened for public use. •
Based on the results of this monitoring and any new conditions of the project area (i.e.,
aesthetic changes, recreation use patterns, changes to project recreation sites and trails as
a result of construction, etc.). Staff recommends that California DWR update the
project's existing Recreation Plan by December 30, 2021, to incorporate the approved
changes in the above mentioned amendment orders and to incorporate any changes
needed as a result of the previous two years of monitoring. The updated Recreation Plan
should be developed in consultation with, at a minimum, the project's Recreation
Advisory Committee.
Finally, staff recommends that California DWR incorporate components into its
comprehensive Revegetation and Invasive Species Mitigation Plan (as introduced in
Section 6.7-Terrestrial Resources) that will address the revegetation and restoration of
the individual recreation sites and trails affected by the response and recovery actions.
This should include details on the revegetation proposed to restore disturbed areas at each
site and trail, the removal of any invasive species introduced any site or trail during the
proposed work, and a plan and schedule by which California DWR will monitor and
report on the revegetation and restoration efforts. The measures outlined in the plan
should aim to restore the recreation environment, at all affected sites and trails, to pre-
emergency conditions to the greatest extent possible.
While the emergency, response, and recovery actions will have short-term adverse
effects on recreation resources at the project, implementation of the above staff
recommended measures will minimize both the duration and severity of those effects.
Additionally, requiring California DWR to update its Recreation Plan will ensure that
progress is made towards restoring and opening license required recreation, inform the
Commission and the public of any continued adverse effects (i.e., continued closures,
changes to required amenities, etc.), and allow interested stakeholders and the Recreation
109
Advisory Committee the opportunity to comment and participate in the restoration of
recreation in the area.
6.11 Aesthetics
•
6.11.1 Affected Environment
The Oroville Facilities are in Butte County and can be placed into five
aesthetically distinct geographic areas: Lake Oroville; the Thermalito Diversion Pool and
Thermalito Forebay; the Thermalito Afterbay; the low flow channel; and the OWA. The
eastern half of Butte County includes Lake Oroville and the spillways and the Thermalito
Diversion Pool. This eastern part of the county is largely undeveloped and retains much
of its natural character, with some scattered rural residences and small communities.
Vegetative cover in the foothills area includes chaparral, mixed foothill pine/oak
woodland, and mixed coniferous forest. The western half of Butte County includes the
Thermalito Forebay and Afterbay. This western part of the county is primarily flat, and
land use is largely agricultural with scattered areas of development ranging in intensity
from scattered rural residential to suburban to urban.
Lake Oroville is impounded by Oroville Dam, a massive earthfill structure that
rises 770 feet above the floor of the Feather River Canyon and is about 1.3 miles in
length. Oroville Dam is a major visible feature in the Oroville area. Its scale, shape,
texture, and color contrast with the surrounding landscape. The face of the dam is
composed of gravel and rock, and supports some plant life such as annual grasses, forbs,
and small shrubs. However, during most of the year it remains brown in color. The
dam's concrete and metal spillway, spillway control gates, and emergency spillway weir
are located at the north end, and are visually important elements of the Oroville Dam
complex that contrast with the earthfill portion of the dam. The visually prominent 178-
foot wide concrete spillway chute extends from the top of the slope more than 3,000 feet
down the spillway headworks and into the plunge pool at the canyon bottom. Because of
the size of Oroville Dam and its southwest orientation toward the city of Oroville and the
Sacramento Valley, it is a prominent visual landmark.
6.11.2 Environmental Effects
The various response and recovery efforts conducted by California DWR have and
will alter the landscape and viewshed temporarily and permanently, depending on the
action(s) in the vicinity of the Oroville Dam and spillways. The altered viewshed will be
noticeable to residents, recreationalists, and those passing through on the surrounding
highways. The construction proposed for the emergency's response and recovery
combined with the previous transmission line construction for California DWR and
PG&E will also have a—major and long-term adverse effect on aesthetic resources,
110
primarily as a result of permanent vegetation removal along the transmission line
corridor.
During the response and recovery efforts, the project area will be dominated by
construction, heavy machinery, demarcated and/or closed areas, and a flurry of human
activity, affecting the natural landscape, the public's view of the project area, and a
recreationist's aesthetic experience. These effects will be short-term and will not have
lasting impacts on the aesthetic environment, as they will be removed once the
construction activities are complete.
The introduction of construction supporting facilities and access roads, and the
increase in traffic including the movement of contractors and haul routes for the recovery
efforts will add development and congestion to an otherwise rural and natural area.
However, traffic will return to normal conditions following completion of the recovery
activities.
Multiple proposed actions require land clearing and grubbing. California DWR
notes that this will occur in more than a 300-acre areas within the proximity of the
spillways and the borrow area creating a visual disturbance around the project.
The trench required for the 13.8-kV Hyatt-Thermalito Transmission Line and
communication cable would impact the aesthetic appeal for hikers utilizing the Dan
Beebe Trail. Revegetation of disturbed areas will help to minimize any the effects had on
several previously discussed resources and the adverse aesthetic effects. However, the
time it will take to restore the land to pre-emergency conditions is unknown and
dependent on the time it takes to reestablish vegetation.
The repaired main and emergency spillways will exist in the same physical
footprint, however the emergency spillway which was previously an undeveloped slope
will be replaced with the use of roller compacted concrete apron to the secant pile wall.
The change from a natural slope to a concrete wall will change the public's view of the
Oroville project area. While not yet defined by California DWR, there will likely be
constructed roads and spoil piles that may also remain a permanent addition to the
previously natural landscape.
6.11.3 Staff Recommendations
It is unclear if and how California DWR intends to restore roads and supporting
facilities that will no longer be needed following the recovery phase. It is also unclear if
and/or how the borrow area and spoil piles would be restored. For that reason, staff
cannot fully evaluate the full extent of the adverse effect the spillway response and
recovery work will have on aesthetic resources.
111
However, staff agrees with California DWR that its proposed Restoration Plan will
be necessary for the protection of several resources and the restoration of the pre-
emergency aesthetic environment where feasible. A comprehensive Restoration Plan for
the project, should further describe California DWR's rehabilitation efforts of disturbed
areas following construction including but not limited to: the removal and restoration of
specific support facilities, roads, borrow area, and spoil piles; and as discussed above
recreation sites and trails. The plan should be developed in coordination with or as a
component of the Revegetation and Invasive Species Mitigation Plan discussed further in
the sections above; demonstrating that California DWR has taken into consideration the
cumulative effects of its proposed actions to the various resources including a discussion
•
within the plan on how its proposed measures collectively will restore or improve the
aesthetic environment for the public. While the cumulative effects have and will
continue to significantly affect the viewshed of the project during construction; if
implemented, the Restoration Plan should reduce the overall adverse visual effects to the
project area in the long-term.
6.12 Air Quality
6.12.1 Affected Environment
The project area is generally rural in nature, with localized areas of residential
development near the project giving way to higher levels of commercial and industrial
development as one travels downstream from the project towards the city of Oroville. As
a result, airborne pollutants are generally lower than the California average, and
comparable to the average across these United States. However, nearby wildfires can
infrequently, but severely impair air quality in the region, most notably by increasing
concentrations of particulate matter, nitrogen oxides, and volatile organic compounds,
and resulting in ground level ozone production and smog.
The metamorphosed volcanic bedrock of the project area contains asbestiform
actinolite, which, when disturbed and made airborne, is a respiratory health hazard.
There are no known surveys of background airborne asbestiform mineral levels for the
area. However, the amount of vegetation, relatively limited amount of ground
disturbance, and periodic rainfall likely limited significant amounts of airborne
asbestiform minerals to locally disturbed sites, existing dirt roads, or barren areas under
high wind conditions.
6.12.2 Environmental Effects
The activities associated with the response activities, including clearing of
vegetation, construction of new roads, and mobilization of large construction equipment,
resulted in moderate adverse effects to air quality. Activities related to the removal of
vegetation from areas within the emergency spillway directly increased dust emissions,
112
and the denuded surfaces resulted in a greater likelihood to produce airborne particulates
in the future. The airborne particulates caused by disturbance of native rock and soils
also contained asbestiform minerals. As response actions took place in late winter, levels
of soil moisture would have been greater, reducing the magnitude of dust generation
caused by California DWR's activities. Furthermore, California DWR also utilized water
trucks to spray areas where generation of dust would have been more likely, to reduce
impacts on the resource area. Additionally, much of the dust generated during response
activities would have remained within the project area, or immediately downwind of the
site, and would have either settled or dispersed before travelling a significant distance.
During the response, California DWR directed its contractors to mobilize all
available equipment and transport it to the project area. These vehicles were in addition
to the background level of traffic that occurs in the area, and their use increased the
concentration of particulate matter, organic compounds, and nitrogen oxides at the
spillway sites and in the adjacent areas used to access the project. The expansive and
various routes used by these vehicles resulted in exhaust emissions throughout the region,
and included normally heavily travelled roads, as well as those located in residential
areas.
The recovery activities similarly will result in significant impacts on air quality,
but on a greater scale. The establishment of a borrow area at the site east of the main
spillway, the addition of material to the three spoils piles, and rock crusher operation for
the production of concrete, will increase the number of sources for dust, and intensity the
release of airborne asbestiform minerals. Furthermore, reduced soil moisture levels in the
summer and autumn, when much of the recovery activities would take place, will raise
the capacity of the area to produce airborne dust. Air sampling during early recovery
activities indicated the presence of asbestiform minerals within, and at the perimeter of
the spillway construction area. The sampling results showed that concentrations of
asbestiform minerals at most locations around the project site were below the permissible
exposure limit established by the U.S. Occupational Safety and Health Administration.
However, air samples taken near active rock crusher operations exceeded the limit and
required the use of respiratory protection.
California DWR proposes to haul 25,000 cubic yards of pervious fill
approximately 17 miles from a commercial quarry to the main spillway. California DWR
has indicated that, to transport the material, it would use the route shown in Figure 6
above. This route travels, at least part of the way, through commercial and residential
areas, and will expose visitors and residents to unusually high amounts of dust emissions
from the payload, as well as diesel exhaust emissions including particulates, nitrogen
oxides, and odorous fumes.
The licensee has proposed a number of methods to reduce its impacts on air
quality. California DWR would continue to operate sprayer trucks, which moisten
113
unpaved roads, spoil piles, and other barren areas, to reduce dust emissions. California
DWR would also direct its contractors to limit vehicle speeds across unpaved roads and
staging areas, as well as require vehicular access to all areas of spoil piles near residences
so the entire surface could be treated with water. Furthermore, California DWR would
install rumble strip where unpaved roads meet paved routes to limit the amount of dust
incidentally transported out of the construction area. During blasting, California DWR
proposes to place a moistened soil overburden atop the blast area, utilize blasting mats,
and avoid blasting during high winds. While processing material for aggregate
production, California DWR would moisten material conveyed into rock crushing or
screening devices, and monitor the intensity of dust plumes generated by such activities.
California DWR also intends to limit impacts from hauling bulk material by installing
track-out plates between paved and unpaved areas, washing or moistening the payload,
placing tarpaulins on haul trucks, maintaining an adequate freeboard within the cargo
bed, and inspecting belly-dump truck seals to prevent spillage. Additionally, California
DWR intends to protect bare surfaces by applying gravel or seeding where applicable.
California DWR's response and recovery actions have had, and will likely
continue to have a detrimental impact on air quality. Owing to the unique geology of the
area, dust generation could result in release of asbestiform minerals, well known to cause
chronic respiratory disease. However, previous air quality sampling indicates most
personnel and the general public would not be adversely impacted by the release of
asbestiform minerals. Those personnel that are involved with rock crusher operations
would be provided adequate respiratory protection, and California DWR would monitor
dust generation and curtail rock crushing activities if the dust plume becomes excessive
or migrates to unprotected areas. Furthermore, though trucking material through
neighborhoods could expose the public to harmful airborne dust, California DWR's plan
to wash or wet the material and enclose it should reduce any risk to the public to
acceptable levels. Though construction would have an adverse, moderate, and short-term
effect on air quality at the project site and along routes used to transport material and
equipment, the protection and mitigation methods described above should reduce the
impact to a permissible level during construction.
6.12.3 Staff Recommendations
California DWR has not extensively indicated the methods it would use to limit
impacts on air quality following construction activities. Though California DWR has
discussed a project area restoration and a planting/revegetation plan, it has not indicated
what would be included in the plans or provided an outline for them. We recommended
that these plans include provisions to identify how California DWR would restore
disturbed and barren lands, either through vegetation or other methods, to prevent the
construction site and other affected areas from contributing to continued adverse effects
on air quality.
114
6.13 Transportation
6.13.1 Affected Environment
The project is located in a rural area served by roads maintained by the state, Butte
County, the City of Oroville, and California DWR. Two major state highways, route 162
(travelling generally east-west across the project area), and route 70 (travelling south to
the Sacramento area) provide access to the region. Various county and City of Oroville
roads provide access to the immediate project area, some of which are used exclusively
by project visitors. California DWR also maintains a number of roads to gain access to
project lands and facilities. These roads are generally paved, in good condition, and the
state of the roads was not a determining factor in limiting the type or volume of traffic,
within reason. However, some of the less utilized access routes are unpaved and in
poorer condition. These included roads used to access informal recreation sites, and car-
top boat launches.
State Highway 162 passes approximately 1.5 miles south of the Oroville Dam and,
from the highway, the dam is most readily accessed via Canyon Drive, owned and
maintained by Butte County. Canyon Drive passes the dam at its east side, where it
intersects with Oroville Dam Road, which travels across the crest of the dam allowing
access to the east side of the main spillway. A second road, Oro Powerhouse Road,
crosses the toe of the dam, and similarly allows access to east side of the main spillway.
Oroville Dam Road also provides vehicular access to the west side of the main spillway,
the emergency spillway, and various recreational facilities via a bridge crossing the main
spillway adjacent to the gate structure. Additionally, a 4.8-mile-long, single-lane
unpaved road, known as the Burma Road, follows the north and west shoreline of the
Thermalito Diversion Pool between the west side of the Oroville Dam emergency
spillway area and the Thermalito Diversion Dam. This road was constructed for access
during initial construction of the project but is otherwise unimproved and used as a
recreational hiking, biking, and horseback riding trail as well as for safety patrols using
passenger vehicles.
Due to its rural nature, vehicular traffic in the project area is comparatively low
and congestion is generally rare. However, heavy use of marinas, parking lots, and other
recreational facilities related to the project has resulted in localized short-term impacts
during peak holiday periods. In the FEIS, Commission staff estimated that non-resident
visitors to the project frequently use approximately 35 miles of county-maintained road,
resulting in an annual additional maintenance cost of$10,010 (FERC 2007).
6.13.2 Environmental Effects
Immediately after becoming aware of the severity of the February 2017 incident,
California DWR established an emergency contract and required its contractors to
115
expeditiously mobilize all available equipment and necessary material to the site. As
such, California DWR did not conduct a baseline review of road and traffic conditions,
and chose access routes without considering the effects on the infrastructure or other road
users.
Subsequently, California DWR retained the services of a geotechnical and survey
contractor to assess the magnitude and scope of physical damage to the roads caused by
vehicular traffic related to the response and initial recovery activities. The contractor
conducted a survey on March 2, 2017 to identify damage California DWR and its
contractors were causing, with a follow-up survey on June 20, 2017, to evaluate the rate
at which damage was progressing. California DWR reviewed the findings of the surveys
to conduct a post-impact analysis and determine what repairs would be needed for the
roadways.
The survey results indicate the use of public roads in relation to response and
ongoing recovery activities have heretofore, likely damaged 17 roads owned and
maintained by Butte County, nine roads owned and maintained by the City of Oroville,
and one road, Highway 162, owned and maintained by the state (Figure 17). Such
damage includes rutting, potholing, and alligator cracking. California DWR estimates the
cost to repair damage to the city roads at $342,095, and the cost to repair roads owned
and maintained by the county at $3,844,989. Canyon Drive, owned by Butte County,
suffered significant adverse damage and California DWR fully reconstructed the road.
Butte County and California DWR also mitigated significant adverse damage to several
other roads by making repairs and adding steel plates to the road surface.
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117
During the response and initial recovery activities, California DWR directed its
contractors to develop and implement a temporary traffic control plan. The plan is
required to include provisions to install temporary railing, barricades, illuminated
signage, road markings, and to make use of flaggers to direct traffic through and around
construction access areas. The contractors, through the plan, would also be required to
consider needs of the public by establishing designated haul routes and public notification
thereof, and avoiding residential streets, to the extent possible. California DWR's
requirements for the plan stipulates that it follow California Department of
Transportation methodology, and would also conform to best management practices as
requested by the Commission in a December 14, 2017 letter. Furthermore, to improve
safety, California DWR coordinated with local law enforcement to ensure compliance
with safe and legal driving practices. California DWR also closed approximately 3 miles
of Oro Dam Boulevard, located immediately southeast of the spillway and dam area, used
extensively by project related traffic. Similarly, the closure of recreational areas near the
spillways and dam, would indirectly improve road safety by reducing the number of
visitors to the site, and decrease the possibility of vehicular conflicts.
During the response activities, California DWR constructed a number of roads to
access the emergency spillway and prepare it for use. Following use of and damage to
both spillways, California DWR constructed additional roads to replace access corridors
lost to erosion. This includes a road constructed within the waters of the Thermalito
Diversion Pool, identified as the lower haul road. Additionally, noting that heavy vehicle
access to the west side of the main spillway and emergency spillway was limited to the
bridge across the main spillway, California DWR improved the Burma Road as an
alternate access route. California DWR widened the road by up to 9 feet, resulting in a
minimum road width of 28 feet, including flanking drainage ditches. California DWR
cut into hillsides and added fill to low areas and drop offs to widen the road.
Additionally, California DWR also installed new box culverts at two stream crossings,
replaced pipe culverts in various other locations, trimmed vegetation, and added rock to
the road bed.
Following the completion of response activities and transition to recovery actions,
California DWR intends to continue using the myriad roads constructed near the
spillways for the initial emergency response. California DWR would use these roads to
deliver materials to the concrete batch plants, transport material to and from spoil piles,
truck concrete to the spillway areas, and provide access for the erection of cranes and
other heavy equipment. California DWR also proposes to use nine public roads as haul
routes during recovery activities. Moreover, California DWR proposes further
improvements to the Burma Road and interconnected routes which include paving,
widening to 30 feet around curves, placement of additional fill, vegetation removal, and
extension of culverts.
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As noted above, California DWR would obtain approximately 25,000 cubic yards
of pervious fill from an off-site quarry. Delivering this material to the spillway area
would require approximately 1,400 round trips using standard, commercially available
dump trucks. The haul route for these trips would use Table Mountain Boulevard, state
highway 70, Oro Dam Boulevard, and Canyon Drive. California DWR indicates trucking
this material from the quarry to the main spillway would take about 5 months, resulting in
an average of nine round trips per day. California DWR also indicates the trucking
would take place during the day as well as night, as required by constraints, but would be
preferentially scheduled to occur during off-peak hours.
To help mitigate for the damage to public roads caused by transporting material
and equipment to the project site, California DWR has entered into road damage
agreements with Butte County and the City of Oroville. These municipalities have also
sought reimbursement from FEMA for the costs of road repair. California DWR states
that under the agreements, it would provide reimbursement only in cases where the city
or county have made a claim and scheduled an inspection with FEMA. Additionally, the
agreements would apply to the nine identified haul routes whereas damage to the
17 roads used for project purposes but not classified as haul routes would be repaired
under agreements California DWR has with its contractors. Overall, California DWR
estimates that 28.31 miles of road would be impacted by recovery activities.
California DWR's activities have resulted in significant, and sometimes severe
impacts to transportation resources in the project area. The extensive use of heavy
vehicles, especially on roadways not intended to support such equipment has, and would
likely result in meaningful and detrimental effects on the roads and other users for a
period of several years. Additionally, activities following completion of construction
would include demobilization and associated transportation of the concrete batch plants
and cranes.
California DWR's activities resulted in significant adverse effects to area roads.
However, some of the adverse impacts to public roadways have already been mitigated,
as California DWR and Butte County have rebuilt or repaired several roads.
Additionally, California DWR's proposal to enter into road damage agreements with
local municipalities should, following completion of all activities, result in the return of
the affected roads to a condition at least comparable to that before the initial response
activities and ensure the adverse effects do not continue in the long term.
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6.13.3 Staff Recommendations
Although California DWR has proposed to enter into road damage agreements
with Butte County and the City of Oroville, California DWR has not indicated that it
intends to file these agreements with the Commission for review. To ensure that
California DWR mitigates the damage caused to public roads as a result of its actions,
staff recommends the Commission require California DWR to prepare and file a Road
Mitigation Plan that would indicate the nature by which California DWR intends to repair
affected roads, staging areas, and parking lots through its contractors or reimburse Iocal
municipalities for repairs to their respective roads damaged by trucking related to the
proposed action.
Additionally, in the course of the response and recovery activities, California
DWR has, or would construct new access roads or improve existing roads, notably
replacement roads to the spillway sites and the Burma Road and its adjoining roads.
California DWR has not yet indicated the future disposition of these roads, but we
support the restoration of most access roads constructed adjacent to the spillways.
following construction. However, because of the potential future usefulness of the
improved Burma Road, California DWR would likely maintain it as a redundant access
route to the emergency spillway area and possibly return it to use as part of the Dan
Beebe recreational trail. Commission staff recommends California DWR be required to
indicate its plan for these roads within the aforementioned area-wide Restoration Plan,
and describe through what processes it would restore any temporary roads to the original
condition or retain or further improve more permanent roads.
6.14 Noise
6.14.1 Affected Environment
The project is located in a rural, undeveloped, natural setting, and noise from the
project during normal operation was limited to buzzing or humming from electrical
equipment and transmission lines, employee's vehicles, and noise from occasional spill
events. Recreational users within the area also produced various amounts of noise, from
boats, generators at campsites, visitor's vehicular traffic, and conversations. Wildlife
• calls were also audible in the vicinity. The immediate project area lacks permanent
residences, though the Kelly Ridge development, located about 1 mile southeast of the
main project area, houses approximately 2,700 persons.
To the west of the project, within the City of Oroville, the type and volume of
noise is typical of a small, suburban city. Generated noise is most frequently related to
vehicular traffic, light industry, and household equipment. In this environment, noise
production is greatest during the day, as the number of sources falls significantly at night.
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6.14.2 Environmental Effects
The response activities required the use of earth-moving equipment and tools to
remove vegetation. As a result, the response activities resulted in significantly more
noise than would otherwise be found in the project area, and such activities would have
become the primary source of noise. Additionally, California DWR conducted its
response activities throughout the day and night. Although those most impacted would
have been the personnel operating or directing the equipment themselves, the Kelly
Ridge residential development is close enough that some of the noise would have been
audible from the residences. Furthermore, during the response activities, California
DWR made use of helicopters over the main and emergency spillways. California DWR
used the upper parking lot, adjacent to.the Kelly Ridge development, as site for the
aircraft to retrieve erosion control materials and to stage other equipment. California
DWR conducted helicopter flights during daylight only, though other activities at the
upper parking lot would have taken place day and night. As the housing development is
at a moderate distance, and located approximately 400 to 500 feet higher in elevation
than the work area, much of the noise generated by the earth moving and vegetation
clearing activity would have been attenuated by the time it reached the residences.
However, the helicopter flights and activity at the parking lot would have had led to a
greater amount of noise within the Kelly Ridge residential area. Although the amount of
noise from the response activity decreased at night, it still would have been detectable to
the residents, though not necessarily intrusive.
As stated previously, California DWR requested that all available equipment in its
vicinity be transported to the project during the response activities. The emergency
nature of the work necessitated a schedule that required travel during day and night,
Many of the routes used to access the project were through residential areas which did
not typically include this type of traffic. As such, these residences and areas were
temporarily exposed to a type and magnitude of noise atypical for the locations.
During recovery operations, the amount of noise generated at the project site
would be similar to that produced during the response activities. The constant use of
heavy trucks, rock crushers, excavators, and other equipment would result in an amount
of noise and ground vibrations that far exceeds that which is typical to the area.
However, California DWR states it intends to reduce the impact by proposing that idling
vehicles have their engines turned off, equipment such as drills be used rather than
impact tools where possible, mufflers be installed on equipment, and preference be given
to hydraulic or electrically operated equipment over pneumatic equipment.
California DWR would use explosives to remove parts of the existing main
spillway and prepare the foundation for its replacement. Though blasting would be
intermittent, it would cause air pressures and vibrations much greater than other
construction activities. However, California DWR states it would place crushed stone
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over the explosives in the blast holes to reduce pressures and fly rock. California DWR
would also limit blasting events to daylight hours, when noise would be less disturbing to
the nearest residences.
During the recovery activities, California DWR proposes to reduce the number of
haul routes it would use, but would continue to transport material and equipment during
both day and nighttime hours. Additionally, several of the remaining haul routes are
located in residential areas. To reduce the amount of noise from vehicles passing through
these normally quiet areas, California DWR intends to install and/or maintain vehicle
mufflers, direct drivers to reduce speed, and avoid engine braking when feasible.
Generally, California DWR's actions have and would continue to significantly
increase the amount of noise at the construction site, and in adjacent areas used to
transport material and equipment to and from the spillway area. Though the duration of
the noise would be finite, cumulatively, California DWR's activities would result in a
noise impact for approximately two years. Noise at the construction site and upper
parking lot would be audible in the Kelly Ridge residential development, and would be
considerably greater than the amount of noise prior to February 2017. However, the
distance and topography of the area would reduce the intensity of noise heard in the
development. Furthermore, limiting particularly loud actions such as helicopter flights
and blasting to day time hours would reduce the amount of noise generated at night, when
it would be particularly detrimental.
Outside of the immediate construction area, noise generated from vehicles would
impact normally quiet residential areas, day and night, when it would have the greatest
effect. Although California DWR has proposed to implement a number of measures to
mitigate for this noise, it would still moderately adversely affect those residences along
• the active haul routes in the short term.
6.14.3 Staff Recommendations
Due to the limited noise effects and California DWR's proposed mitigative
measures, Commission staff does not recommend any further measures.
6.15 Cumulative Impacts
The Council on Environmental Quality's regulations for implementing the
National Environmental Policy Act indicate that an action may cause cumulative impacts
on the environment if its effects overlap in space or time with the effects of other past,
present, or reasonably foreseeable future actions, regardless of the agency, company, or
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person undertaking the action.62 Cumulative effects can result from individually minor,
but collectively significant, actions taking place over a period of time.
We conclude that the proposed action is likely to have a cumulative adverse effect
on geology and soil resources, water quality, fishery and aquatic resources, terrestrial
resources, and aesthetic resources. California DWR's response and recovery actions had
a significant, permanent, and adverse effect on geology and soil resources at the project
through material removal near Oroville Dam and potentially due to riverbank sloughing
and erosion. However, California DWR's measures to reduce erosion, along with staff's
recommended measures below, would help mitigate the adverse effects to geological and
soil resources.
The impaired water quality from repeated use of the damaged spillway and use of
the emergency spillway created adverse conditions for fishery resources in the Feather
River and by extension, in the Feather River Fish Hatchery. The impaired water quality,
combined with repeated flow reductions, caused significant mortality of fish in the
Feather River and in the Feather River Fish Hatchery. In addition, federally-listed
spring-run Chinook salmon and Central Valley steelhead were adversely impacted by the
impaired water quality and sharp flow fluctuations. These losses would be mitigated
below a significant cumulative impact by the additional measures described below.
Regarding terrestrial resources, we conclude that the response and recovery
actions would have a both short and long-term significant adverse effects, when
combined with earlier land disturbance associated with California DWR and PG&E
transmission line relocation activities. However, sufficient habitat exists in the areas
surrounding the project construction and disturbance area, such that the majority of
wildlife and avian species are expected to disperse to less disruptive locations. The
response and recovery actions may affect but are not likely to adversely affect the valley
elderberry longhorn beetle. Similarly, previously approved and the proposed
construction disturbances would have an adverse effect to aesthetic resources. The
effects to terrestrial and aesthetic resources would be offset to the extent possible,
through required mitigation activities, including the development and implementation of
the Oroville Emergency Response and Recovery Project Area Restoration Plan and an
Elderberry Relocation Plan.
Regarding recreation resources, the response and recovery actions are expected to
result in temporary closure of project recreation facilities. California DWR's effort to
mitigate recreation impacts by improving and expanding recreation facilities in other
locations on Lake Oroville indicates that the response and recovery actions will have a
minor temporary adverse impact to recreationalists. With the reopening of recreation
sites and implementation of its Recreation Plan, the response and recovery actions will
62 40 C.F.R. § 1508.7 (2018).
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not have a lasting cumulative impact to recreation resources. In addition, the
construction and expansion of boat ramps will provide a long-term beneficial effect to the
area by providing additional opportunities that were not available prior to the emergency
event.
Regarding cultural resources, the initial response activities and recovery efforts
have resulted in major and minor adverse effects to cultural and historic resources at the
project. However, implementation of the executed PA, ongoing consultation with the
California SHPO and tribes, implementation of avoidance and minimization measures
(such as the presence of archeological and tribal monitors during construction near
sensitive areas), and carrying out the agreed-upon mitigation and data recovery measures
at affected archeological sites would negate any cumulative impacts to cultural resources
from recovery activities.
•
Finally, water quantity, air quality, transportation, or noise resources, the response
and recovery actions should not have a significant cumulative effect either due to the
temporary and minor effects to these resources from the proposal or because there are no
other actions that may affect the resource.
7.0 CONCLUSIONS AND RECOMMENDATIONS
7.1 Comprehensive Development and Staff-Recommended Measures
We conclude that the no-action alternative (leaving the damaged spillways in
place) is not feasible. The no-action alternative would impair project operations and
would impede California DWR from passing a full range of project inflows downstream,
creating an unacceptable risk to public safety. California DWR also considered
numerous scenarios to urgently restore the full operational capacity of the main and
emergency spillways due to public safety concerns. In this consideration, California
DWR consulted with, and continues to consult with, the Commission's D2SI and the
California DSOD. The final design represents the preferred alternative for quickly
restoring full operational capability at Oroville Dam. The proposal would result in
adverse effects to aquatic, terrestrial, cultural, transportation, noise, and recreation
resources. These effects would be mitigated, to an extent, by California DWR's proposed
protective measures, by staff's recommended protective measures below, and by the
• process and measures prescribed in the PA with the California SHPO for protection of
cultural resources.
7.1.1 Staff-Recommended Measures
(1) California DWR should be required to file a post-construction Water
Quality Protection Plan. The plan should includemeasures to prevent erosion at any
areas impacted by construction efforts. At a minimum, the plan should contain measures
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for long-term water quality protection at disrupted soil surfaces, spoil piles, and any other
unstable sources of turbidity. The plan should also contain measures for the ultimate
disposition of the spoil piles and measures that California DWR will implement to
prevent contaminated water from the settling pools at the base of the main spillway from
being discharged to the Thermalito Diversion Pool after construction ends.
(2) California DWR should be required to take actions to mitigate for the
deficit of 300,000 spring-run Chinook from 2017 hatchery losses. Staff recommended
measures include an increase to hatchery production in a subsequent year, habitat
improvements, or capital investment in fishery projects. Any mitigation could be
combined with other important fishery mitigation or improvements required in this
proceeding.
(3) To mitigate for the effects to terrestrial, recreational, and aesthetic
resources, California DWR should develop a comprehensive Revegetation and Invasive
Species Mitigation Plan. At a minimum the plan should include measures to:
1) maintain and monitor replanted vegetation for a minimum of five years or until the
vegetation reaches a survival rate of 70 percent and invasive plants are not present in the
revegetated area; (2) with the exception of areas designated for recreational use parking,
revegetate the staging, laydown areas, and other applicable areas used for construction
support and/or disturbed by construction activities; as well as the areas disturbed by the
installation of the 13.8-kV Powerline and Fiber Optic Communication System along the
Dan Beebe Trail; (3) use native vegetation management planting methods (e.g., use of
certified weed-free straw and native plant species) to revegetate the disturbed areas; (4)
establish a schedule that specifies when monitoring will occur during the calendar year
and what monitoring methods will be used; (5) file annual progress reports by March 1 of
the subsequent year, for at least the first five years to describe both the progress of
revegetation efforts as compared to the specified benchmark survival rate of 70 percent
and, if benchmarks are not met, any needed modifications to management of planted
seedlings; (6)implement best management practices to prevent the introduction and
spread of invasive plant species; and (7) create a plan to address invasive and noxious
weeds should they be found during the course of the monitoring effort.
(4) To ensure continued protection of the Glen Pond nesting territory occupied by
a bald eagle pair, California DWR should continue to implement the following measures
to prohibit human activity as the response and recovery efforts take place:
(1) administrative closure of land and shoreline areas around the bald eagle nest
territories to human entry during the nesting season; (2) signage, patrol, and enforcement
of closure; (3) nest and population surveys; (4) habitat improvement measures; and (5)
limitations on current and future habitat disturbance. As detailed in the Commission's
FEIS for the relicensing, California DWR prepared and implemented bald eagle territory
management plans for four bald eagle nest territories which were active on or within 0.25
miles of project lands (FERC 2007).
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(5) To mitigate for the potential to affect the valley elderberry longhorn beetle,
California DWR proposed, and staff agrees, that it should develop an Elderberry
Relocation Plan for Commission approval. California DWR should consult with the
FWS, and the plan should include at a minimum comments and measures previously
discussed with the FWS and should incorporate measures, as applicable, from the FWS's
2017 Framework for Assessing Impacts to the Valley Elderberry Longhorn Beetle.
(6) California DWR should be required to implement any terms or conditions
resulting from the pending consultation with NMFS. Once the terms and conditions have
been issued (if any), California DWR should be required to file a schedule for
implementing these requirements.
(7) To keep the Commission and the public informed about the available
recreation at the project and the completion of approved recreation facilities, and to
ensure the recreation needs of the public are being met, staff recommends that California
DWR provide Recreation Monitoring Reports for 2019 and 2020, at a minimum. The
monitoring reports should include: 1) documentation of the effects that the closed sites
are having on the remaining project-required recreation, for example, whether the closed
sites are driving increased use of open sites at or above use capacity, if increased use is
requiring additional maintenance and how that is being handled, any increased public
safety issues, etc.; 2) a proposal, plan, and schedule for mitigation if recreation use at
open sites exceeds their use capacity; 3) an update on the use of Burma Road; and 4) an
updated timeline of when closed sites may begin to be restored and opened. Based on the
results of this monitoring and any new conditions of the project area (e.g., aesthetic
changes, recreation use patterns, changes to project recreation sites and trails as a result
of construction, etc.), staff recommends that California DWR update the project's
existing Recreation Plan by December 30, 2021, to incorporate the approved changes in
the 2017 and 2018 recreation plan amendment orders and to incorporate any changes
needed as a result of the previous two years of monitoring. Any ensuing revision to the
Recreation Plan should also be developed in consultation with the project's Recreation
Advisory Committee.
(8) To describe rehabilitation efforts of disturbed areas following construction, the
California DWR proposed, and staff recommends, a project-area-wide Restoration Plan.
The plan should: (1) identify which features developed exclusively for response and
recovery activities, including but not limited to roads, borrow area, and spoil piles, would
be restored to pre-construction conditions; (2) precisely describe the methods by which
the disturbed areas would be restored at the spillways, including methods to make the
restored areas aesthetically congruent with the surrounding, undisturbed landscape; (3)
identify those facilities that had been built or improved to aid construction which would
remain and identify the purposes of such facilities; (4) provide details as to how this plan
will work and be consistent with the project Recreation Plan and the proposed
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Revegetation and Invasive Species Mitigation Plan, (5) restore the pond located west of
Thermalito Diversion Pool railroad bridge to pre-project conditions, (6) develop a
protocol for monitoring and filing progress reports with the Commission, and (7) include
an implementation schedule.
(9) To identify how California DWR would mitigate the damage it caused to
public highways and to ensure such mitigation occurs, staff recommends that the
California DWR prepare and file a Road Mitigation Plan. The plan should: (1) include
the specifications of its road maintenance agreements with Butte County and the City of
Oroville, identifying the roads to which the agreements apply; (2) describe the
stipulations of its contracts through which a third party would repair roads damaged
through California DWR's actions; (3) include details on the disposition of Burma Road
and other construction roads; (4) include details on the repaving of damaged parking and
staging areas where blacktop damage was caused by construction equipment; (5) and
include an implementation schedule.
(10) To mitigate for effects to cultural resources arising from the spillway failure
and subsequent response and recovery efforts, staff recommends that California DWR
continue discussions with the parties to the PA to develop a mitigation plan. Once the
mitigation plan is developed and distributed to the PA parties for review and comment,
California DWR should file it with the Commission for review and approval. Also, to
avoid and minimize effects to cultural resources arising from ongoing recovery work,
staff recommends California DWR continue to implement measures such as avoiding
known resource locations, installing physical barriers, use of hand tools where necessary,
training contractors, designating sensitive areas, and conducting monitoring by both
archaeologists and tribal monitors when construction activities occur near sensitive sites.
In addition DWR should continue to implement the executed PA and consult with the
California SHPO, tribes, and other PA parties as necessary.
(11) To further analyze any adverse effects to soil resources through streambank
sloughing and to aquatic habitat in the lower Feather River from sedimentation, staff
recommends that California DWR prepare and file a Sedimentation and Erosion
Assessment and Mitigation Plan. The plan should conduct a broad assessment of effects
to soil resources, riparian habitat, and the streambed in the lower Feather River, by
comparing pre- and post-event conditions. If the analysis identifies any significantly
degraded areas of mass soil wasting from flow reductions or identifies any areas of
significant sediment deposition from the spillway failure, California DWR should also
include details in its plan for directly or indirectly mitigating those effects. California
DWR should develop the plan in consultation with the California DFW, NMFS, and
FWS and should file the plan for Commission review and approval prior to
implementation.
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7.2 Consistency with Comprehensive Plans
Section 10(a)(2) of the FPA (16 U.S.C. § 803(a)(2)(A)) requires the Commission
to consider the extent to which a project is consistent with federal or state comprehensive
plans for improving, developing, or conserving a waterway or waterways affected by the
project. We reviewed thirteen qualifying comprehensive plans that are applicable to the
proposed action at the-Feather River Project No. 2100. We determined that the proposed
action does not conflict with the following plans:
1. California Advisory Committee on Salmon and Steelhead Trout (1988). Restoring
the balance: 1988 Annual Report. Sausalito, CA.
2. California Department of Fish and Game (1990). Central Valley salmon and
steelhead restoration and enhancement plan. Sacramento, CA. April.
3. California Department of Fish and Game (1993). Restoring Central Valley
streams: a plan for action. Sacramento, CA. November.
4. California Department of Fish and Game (1996). Steelhead restoration and
management plan for California. February.
5. California-The Resources Agency (1989). Upper Sacramento River fisheries and
riparian habitat management plan. Sacramento, CA. January.
6. California Department of Parks and Recreation (2012). Public opinions and
attitudes on outdoor recreation in California. Sacramento, CA. January 2014.
7. California Department of Parks and Recreation (2009). California outdoor
recreation plan-2008.
8. California Department of Water Resources (2014). The California water plan:
Investing in Innovation and Infrastructure-2013. Bulletin 160-13.
9. State Water Resources Control Board (1999). Water quality control plans and
policies. Adopted as part of the State Comprehensive Plan.
10.Central Valley Joint Venture (2006). Central Valley habitat joint venture
implementation plan-Conserving Bird Habitat. U.S. Fish and Wildlife Service,
Sacramento, CA.
11.U.S. Department of the Interior, Environment Canada, Environment and Natural
Resources-Mexico (2012). North American waterfowl management plan; People
Conserving Waterfowl and Wetlands.
12.Fish and Wildlife Service (1989). Fisheries U.S.A: the recreational fisheries
policy of the U.S. Fish and Wildlife Service. Washington, DC.
13.National Park Service (1982). The nationwide rivers inventory. U.S. Department
of the Interior. Washington, DC.
128
8.0 FINDING OF NO SIGNIFICANT IMPACT
In review, the unanticipated failure of the Lake Oroville main spillway and
degradation of the area below the emergency spillway had unintended consequences to
public safety and environmental resources. The preceding analysis examined the effects
of the California DWR's efforts to respond to, and stabilize the emergency situation
created by the main spillway failure and degradation of the emergency spillway area. .
The analysis also examined California DWR's proposed recovery efforts to reconstruct
the main spillway, fortify the emergency spillway, and to re-route a project transmission
line. California DWR has taken measures, and proposes additional measures to mitigate
for the environmental effects from the response and recovery efforts. The Commission
has also recommended additional measures to mitigate for the effects to environmental
resources from California DWR's response and recovery actions. Based on information,
analysis, and evaluations contained in this EA, we find that approval of California
DWR's proposal to reconstruct the main and emergency spillways and to relocate a
project transmission line, along with implementation of the mitigative actions described
above for the response and recovery effort, would not constitute a major federal action
significantly affecting the quality of the human environment.
129
9.0 LITERATURE CITED
Adams, P.B., C.B. Grimes, J.E. Hightower, S.T. Lindley, and M.L. Moser (2002). Status
Review for North American Green Sturgeon, Acipenser medirostris. National Marine
Fisheries Service.
Bash, J., C. Berman, and S. Bolton (2001). Effects of turbidity and suspended solids on
salmonids. Center for Streamside Studies, University of Washington, Seattle, WA.
Bilski, R. and J. Kindopp (2009). Emigration of juvenile Chinook salmon
(Oncorhynchus tshawytscha) in the Feather River, 2005-2007, State of California
Department of Water Resources, Division of Environmental Services.
California Data Exchange Center (CDEC) - Feather River at Mile 61.6 (2018).
hup://cdec.water.ca.gov/dynamicapp/staMeta?station id—FRA (accessed March 15,
2018).
California Department of Fish and Game (CDFG) (1998). A status review of the spring-
run Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento River drainage.
Candidate Species Report 98-01.
California Department of Water Resources (2017). Letter to Federal Energy Regulatory
Commission regarding Oroville Wildlife Area Borrow Material Excavation. Filed
December 12, 2017.
California Department of Water Resources (2018a). Construction Quality and Inspection
Plan-Spillways Specification No. 17-09. Filed May 30, 2018.
California Department of Water Resources (2018b). Application for license amendment.
Filed January 29 and February 13, 2018.
California Department of Water Resources (2018c). 2018 Seasonal FCO Gate Closure
Plan for Lake Oroville. Filed April 17, 2018.
Cavallo, B., R. Kurth, J. Kindopp, A. Seesholts, and M. Perrone (2003). Distribution and
habitat use of steelhead and other fishes in the Lower Feather River, 1999-2000, interim
report for the Department of Water Resources Division of Environmental Services.
Colas, F., J. Baudoin, M. Danger, P. Usseglio-Polatera, P. Wagner, and S. Devin (2013).
Synergistic impacts of sediment contamination and dam presence on river functioning,
Freshwater Biology, 58, 320-336.
130
Federal Energy Regulatory Commission (2007). Final Environmental Impact Statement
(FEIS) for Hydropower License, issued May 18, 2007.
Federal Energy Regulatory Commission (2017). Environmental Analysis for Relocating
Primary Transmission line, issued August 23, 2017.
Federal Energy Regulatory Commission (2018). April 13, 2018 memorandum, providing
water quality monitoring data collected by the California Department of Water
Resources, and sent to state and federal resource agencies following an April 10, 2017
environmental coordination meeting.
Fisch, K.M, B. Mahardja, R.S. Burton, B. May (2014). Hybridization between delta
smelt and two other species within the family Osmeridae in the San Francisco Bay-Delta.
Conservation Genetics 15:489-494
Fox, W. 1951. Relationships among the garter snakes of the Thamnophis elegans
Rassenkreis. University of California Publications in Zoology 50:485-530.
France, J.W., A.A. Alvin, P.A. Dickinson, H.T. Falvey, S.J. Rigbey, J. Trojanowski.
(2018). Independent Forensic Team Report— Oroville Dam Spillway Incident., issued
January 5, 2018.
Gallagher, Assemblyman James; Senator Jim Nielsen; Oroville Chamber of Commerce;
Oroville Recreation Advisory Committee; Town of Paradise; American Whitewater;
Oroville Downtown Business Association; Citizens for Fair and Equitable Recreation;
Feather River Low Flow Alliance; Oroville Rotary Club; Lake Oroville Bicyclists
Organization; Butte County; Sutter County; City of Marysville; City of Gridley; City of
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Landowners' Association; Yuba Sutter Farm Bureau; Live Oak District Chamber of
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10.0 LIST OF PREPARERS
John Aedo— Team Lead, Water Quantity, Water Quality and Aquatic Resources (Fishery
Biologist; M.S. Integrative Biology; B.S. Integrative Biology)
Alicia Burtner— Threatened and Endangered Species (Fish Biologist; M.E.M. Ecosystem
Science and Conservation; B.S. Environmental Science)
Kurt Powers— Cultural and Historic Resources (Wildlife Biologist; M.S. Environmental
Science and Engineering; B.A. Environmental Science and Foreign Affairs)
Steven Sachs, P.E. — Geology and Soils, Air Quality, Transportation, Noise (Civil
Engineer; B.S. Environmental Systems Engineering)
Krista Sakallaris —Terrestrial Resources, Threatened and Endangered Species,
Recreation Resources, and Aesthetics (Environmental Protection Specialist; M.S.
Environmental Science and Policy)