HomeMy WebLinkAboutFERC - Request for Concurrence under the Endangered Species Act - Project No. 2100-185 BUTTE COUNTY
ADMINISTRATION
JUL 16 2018
OROVILLE.CALIFORNIA
FEDERAL ENERGY REGULATORY COMMISSION
Washington,D.C.20426
OFFICE OF ENERGY PROJECTS
Project No. 2100-185--California
Feather River Hydroelectric Project
California Department of Water
Resources
July 5, 2018
Ms. Maria Rea
Assistant Regional Administrator
California Central Valley Office
National Marine Fisheries Service
650 Capitol Mall, Suite 5-100
Sacramento, CA 95814-4700
Subject: Request for concurrence under the Endangered Species Act
Dear Ms. Rea:
The purpose of this letter is to request your concurrence about the impacts arising
from a series of actions related to failure of the Oroville Dam spillways and the
subsequent emergency response and recovery efforts. Oroville Dam is part of the Feather
River Hydroelectric Project No. 2100, located on the Feather River in Butte County,
California. A biological evaluation is enclosed for your review.
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 ogee spillway area at the Feather River Project's Oroville Dam. The licensee
for the facility, California Department of Water Resources (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. Due to high inflows into Lake Oroville (the project reservoir) and reduced
outflow capacity on the main spillway, Lake Oroville overtopped the adjacent emergency
spillway on February 11, 2017, causing back-cutting erosion below the emergency
spillway. The back-cutting erosion threatened the stability of the emergency spillway's
crest structure. As such, California DWR increased operation of the damaged main
spillway to relieve pressure on the emergency spillway, which led to the loss of the lower
portion of the main spillway chute and caused significant erosion under and adjacent to
the main spillway. Impacts were most severe in the Thermalito Diversion Pool
Project No. 2100-1$5 - 2 -
immediately
2 -immediately below the spillways but turbidity and fluctuating flows also impacted the
Feather River extensively downstream beyond the fish barrier dam and other project
works.
In anticipation of dredging and flow fluctuations during California DWR's initial
response, the National Marine Fisheries Service sent a letter to the Commission on
February 24, 2017, providing twelve recommendations to minimize the effects on
federally-listed fish species and their critical habitat below the fish barrier dam. These
fish species included the threatened California Central Valley steelhead, threatened
Central Valley spring-run Chinook salmon, and threatened 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. Rapid flow reductions occurred on four occasions: February 27, March 27,
May 1, and May 19, 2017. During the flow reductions, California DWR conducted fish
rescue and monitoring efforts to offset and assess the extent of the effects on fish species
in the lower Feather River. California DWR also conducted major dredging activities in
the Thermalito Diversion Pool following the initial February 7, 2017 spillway failure,
eventually removing 2 million cubic yards of material from the diversion pool, which
resulted in high levels of turbidity in the lower Feather River
On February 27, 2017, the Commission discussed the February 24, 2017
recommendations with NMFS and California DWR. These included ramping rate
recommendations, minimum flow maintenance, dredging guidance, water quality
maintenance at the Feather River Fish Hatchery, fish monitoring and rescue, 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 California DWR's conflicting efforts to maintain and
observe the structural integrity of the remaining portion of the main spillway. Section 3.3
of the attachment to this letter also provides an itemized response to each of NMFS'
recommendations.
By letter dated March 31, 2017, the Commission designated California DWR as its
non-federal representative to conduct informal consultation with NMFS 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.
California DWR has prepared a biological evaluation that analyzes the effects of
the response and recovery efforts following the February 7, 2017 main spillway failure.
Project No. 2100-185 - 3 -
Four
3 -Four actions had a potential effect on federally-listed species, critical habitat, and
essential fish habitat: 1) use of the emergency spillway and damaged main spillway; 2)
material removal (dredging) in the Thermalito Diversion Pool; 3) four periods of rapid
flow ramping from use of the main spillway; and 4) response activities at the Feather
River Fish Hatchery, located near the fish barrier dam. The action area for these
activities comprises the lower Feather River from the fish barrier dam to the downstream
confluence with the Sacramento River and also the Feather River Fish Hatchery.
The biological evaluation concludes that the above actions had the following
effects on federally listed species:
• California Central Valley steelhead were adversely affected through
stranding of all life stages during the four 2017 flow reductions and
through increased turbidity and its effect on juvenile rearing during use of
the emergency spillway and damaged main spillway.
• Central Valley spring-run Chinook salmon were adversely affected through
juvenile stranding during the four 2017 flow reductions and through
increased turbidity and its effect on juvenile rearing.
• Southern DPS North American green sturgeon were not likely to have been
adversely affected, given their absence from stranding surveys and given
their later spawning time after elevated turbidity conditions had subsided.
• Sacramento Valley Winter-run Chinook salmon were not likely to have
been adversely affected, primarily given their unlikely presence in the
lower Feather River during implementation of the above four actions and
given the-ample opportunity for any individuals present in the lower river
to emigrate from the area prior to excessively turbid conditions.
In addition to the effects above, the biological evaluation investigates the effects in
the lower Feather River to critical habitat for California Central Valley steelhead, Central
Valley spring-run Chinook salmon, and southern DPS North American green sturgeon
and also to essential fish habitat (under the Magnuson-Stevens Fisheries Conservation
and Management Act) for all runs of Chinook salmon. The biological evaluation
concludes that there is no evidence to indicate that critical habitat or essential fish habitat
for these species were adversely affected.'
' Under its National Environmental Policy Act review, the Commission is
investigating the extent to which sediment deposition and bank stability may have
changed in the lower reaches of the Feather River. However, there is no preliminary
indication that significant adverse effects occurred in the known spawning and rearing
areas in the reaches of the lower Feather River affected by recent events.
Project No. 2100-185 - 4 -
Commission
4 -Commission staff has reviewed the licensee's biological evaluation and adopts it
as our biological assessment and essential fish habitat assessment. We request your
concurrence on the above determinations under your agency's modified consultation
procedure for emergencies. 50 C.F.R. § 402.05.
Please file your concurrence with these determinations with the Commission. The
Commission strongly encourages electronic filing of your response using the
Commission's eFiling system at http://www.ferc.gov/doesfiling/efiling.asp. For
assistance, please contact FERC Online Support at FERCOnlineSupport@ferc.gov, (866)
2083676 (toll free), or (202) 502-8659 (TTY). In lieu of electronic filing, please send a
paper copy to:
Secretary
Federal Energy Regulatory Commission
888 First Street, NE
Washington, D.C. 20426
The first page of your filing should include docket number P-2100-185. Thank
you for your cooperation. If you have any questions concerning this matter, contact Mr.
John Aedo at (415) 369-3335 or by email at iohn.aedo0,)fcrc.goy.
Sincerely,
Thomas J. LoVullo
Chief, Aquatic Resources Branch
Division of Hydropower
Administration and Compliance
cc: Mr. Ted Craddock
Department of Water Resources
P.O. Box 942836
Sacramento, CA 94236-0001
ENCLOSURE
STATE OF CALIFORNIA-CALIFORNIA NATURAL RESOURCES AGENCY EDMUND G. BROWN JR.,Governor
DEPARTMENT OF WATER RESOURCES
1416 NINTH STREET, P.O.BOX 942836 M
SACRAMENTO,CA 94236-0001
(916) 653-5791 ,
June 29, 2018
Ms. Kimberly D. Bose, Secretary
Federal Energy Regulatory Commission
888 First Street, Northeast
Washington, DC 20426
FERC Project No. 2100 — Oroville Emergency
Biological Assessment for Federally Listed Anadromous Species
Dear Secretary Bose:
This letter transmits the Department of Water Resources' (DWR) Biological Assessment
(BA) which evaluates the effects of the Oroville Spillway Emergency response during
the winter and spring of 2017 on federally listed anadromous fish species and their
designated critical habitats, protected under the Federal Endangered Species Act (16
USC 156). The BA has been prepared to support Section 7 emergency consultation
between the Federal Energy Regulatory Commission (FERC) and the National Marine
Fisheries Service (NMFS).
By letter dated March 31, 2017, FERC designated DWR as the non-federal
representative to conduct informal consultation with NMFS, pursuant to 50 CFR
§402.08 Section 7 of the Endangered Species Act. Since that time, DWR has been
informally consulting with the NMFS and has kept FERC apprised of its actions. FERC
remains ultimately responsible for all findings and determinations regarding the effects
of the project on any federally-listed species or critical habitat.
If you have any questions or would like to discuss this further, please contact me at
(916) 502-2067 or your staff may contact Gail Kuenster, Chief of DWR's Office of
Regulatory Compliance in the Division of Environmental Services at (916) 376-9780.
Sincerely,
d 0�
Ted Craddock
Oroville Emergency Recovery
Executive Division
Enclosure
cc: (See attached distribution list)
Kimberly D. Bose, Secretary
June 29, 2018
Page 2
cc: Mr. John Aedo
Federal Energy Regulatory Commission
100 First Street, Suite 2300
San Francisco, California 94105-3084
Mr. Thomas J. LoVullo
Federal Energy Regulatory Commission
888 First Street, Northeast
Washington, DC 20426 .
Mr. Alessandro Amaglio
Federal Emergency Management Agency
500 C Street Southwest, Room 706
Washington, DC 20426
Ms. Teri Toye
Deputy Environmental and Historical Preservation Advisor
Federal Emergency Management Agency
10000 Goethe Road
Sacramento, California 95827
State of California.
California Natural Resources Agency
DEPARTMENT OF WATER RESOURCES
BIOLOGICAL ASSESSMENT
FOR FEDERALLY LISTED ANADROMOUS FISHES
for
EMERGENCY CONSULTATION ASSOCIATED
WITH THE OROVILLE SPILLWAY INCIDENT
�i
%V
June 28, 2018
as �»
EDMUND G. BROWN JR, JOHN LAIRD KARLA NEMETH
Governor Secretary Director
State of California Natural Resources Agency Department of Water Resources
State of California
California Natural Resources Agency
Department of Water Resources
BIOLOGICAL ASSESSMENT
FOR FEDERALLY LISTED ANADROMOUS FISHES
for
EMERGENCY CONSULTATION ASSOCIATED
WITH THE OROVILLE SPILLWAY INCIDENT
This report was prepared for the:
National Oceanic and Atmospheric Administration (NOAA) Fisheries West Coast
Region
and
Federal Energy Regulatory Commission
This report was prepared by:
Jason Kindopp, Senior Environmental Scientist (Supervisor)
Department of Water Resources
Alicia Seesholtz, Senior Environmental Scientist (Specialist)
Department of Water Resources
and
Cramer Fish Sciences
13300 New Airport Rd., Ste. 102
Auburn, CA 95602
This report was prepared under the direction of:
Christopher Wilkinson, Chief
Ecological Studies Branch
Gail Kuenster, Chief
Office of Regulatory Compliance
TABLE OF CONTENTS
ExecutiveSummary.........................................................................................................................vi
Listof Acronyms............................................................................................................................viii
1 Introduction............................................................................................................................. 1
1.1 Purpose and Objectives....................................................................................................... 1
1.2 Threatened and Endangered Species.................................................................................. 3
1.3 Critical Habitat and EFH in the Action Area......................................................................... 3
2 Environmental baseline .......................................................................................................... 5
2.1 Location of Facilities and General Description of the Watershed....................................... 5
2.2 Lower Feather River............................................................................................................. 7
2.3 Feather River Fish Hatchery............................................................................................... 10
2.4 Existing Measures to Protect Biological Resources........................................................... 12
2.4.1 Standard Operations for Biological Protection....................................................... 12
2.4.2 Flow......................................................................................................................... 12
2.4.3 Temperature........................................................................................................... 13
2.5 Modeled Water Operations............................................................................................... 13
2.5.1 Bedload Movement................................................................................................. 15
3 Description of the Action...................................................................................................... 19
3.1 Action Area.......................................................................................................................... 19
3.2 List of Actions..................................................................................................................... 19
3.3 National Marine Fisheries Service Recommendations...................................................... 21
i
3.4 Consultation History.......................................................................................................... 25
4 Special Status Species........................................................................................................... 29
4.1 California Central Valley Steelhead (Oncorhynchus mykiss) Distinct Population Segment
31
4.1.1 Listing Status........................................................................................................... 31
4.1.2 Distribution ........................•..................................................................................... 31
4.1.3 Habitat Requirements and Life Ecology.................................................................. 31
4.1.4 Current Status and Distribution.............................................................................. 34
4.1.5 Current Status of Critical Habitat............................................................................ 35
4.2 Central Valley Spring-run Chinook Salmon (Oncorhynchus tshawytscha)........................ 35
4.2.1 Listing Status........................................................................................................... 35
4.2.2 Distribution ............................................................................................................. 35
4.2.3 Habitat Requirement's and Ecology........................................................................ 35
4.2.4 Current Status of Population................................................................................... 35
4.2.5 Current Status of Critical Habitat............................................................................ 37
4.3 Sacramento Valley Winter-run Chinook Salmon (Oncorhynchus tshawytscha) ............... 37
4.3.1 Listing Status........................................................................................................... 37
4.3.2 Distribution ............................................................................................................. 37
4.3.3 Habitat Requirements and Life Ecology.................................................................. 38
4.3.4 Current Status of Population.............. 38
.....................................................................
4.3.5 Current Status of Critical Habitat............................................................................. 39
4.4 North American Green Sturgeon (Acipenser medirostris) southern Distinct Population
Segment........................................................................................................................................ 39
ii
4.4.1 Listing Status........................................................................................................... 39
4.4.2 Distribution ............................................................................................................. 39
4.4.3 Habitat Requirements and Life Ecology.................................................................. 40
4.4.4 Current Status of Population................................................................................... 40
4.4.5 Current Status of Critical Habitat............................................................................ 40
5 Critical Habitat and Essential Fish Habitat............................................................................42
5.1 Critical Habitat and EFH within the Action Area................................................................42
5.1.1 Salmonid Critical Habitat in the Action Area.......................................................... 42
5.1.2 Pacific Coast Salmon Essential Fish Habitat in the Action Area.............................. 43
5.1.3 North American Green Sturgeon Critical Habitat in the Action Area..................... 44
6 Efects of the action ............................................................................................................... 45
6.1 Significance Criteria ........................................................................................................... 45
6.2 Suspended sediment.......................................................................................................... 46
6.2.1 Adult Migration, Holding, and Spawning ............................................................... 48
6.2.2 Eggs and Larvae...................................................................................................... 50
6.2.3 Juvenile Rearing...................................................................................................... 51
6.3 Flow reductions.................................................................................................................. 54
6.3.1 Straying................................................................................................................... 54
6.3.2 Stranding................................................................................................................. 55
6.4 Feather River Fish Hatchery............................................................................................... 58
7 Conclusion............................................................................................................................. 61
7.1 Suspended Sediment ......................................................................................................... 61
iii
7.2 Flow Reductions................................................................................................................. 63
7.3 Feather River Fish Hatchery............................................................................................... 64
7.4 Critical Habitat and Essential Fish Habitat......................................................................... 64
8 Conservation Measures Taken byCDWR ............................................................................. 67
8.1 Additional Proposed Conservation Measure..................................................................... 68
9 Literature Cited ..................................................................................................................... 69
iv
List of Figures
Figure 1. Location of the Action Area............................................................................................. 2
Figure 2. The Feather River watershed, Sacramento-San Joaquin Delta, and San Francisco Say. 6
Figure 3. Releases from Oroville Dam between February 1 and May 31, 2017 and modeled flows
assuming the Oroville Spillway Incident has not occurred ........................................................... 14
Figure 4. Cross section (station 65.93 in the HEC-RAS model) used in the sediment transport
analysis.......................................................................................................................................... 15
Figure 5. Location of 2014 gravel augmentation area in the Feather River................................ 16
Figure 6. Curimulative excess shear stress for the Dso for both flow scenarios............................. 17
Figure 7. Cumulative bedload transport for both flow scenarios................................................ 18
Figure 8. Discharge in the tow Flow Channel and High Flow Channel of the Feather river
between January 1, 2017 and September 30, 2017..................................................................... 21
Figure 9. Turbidity(NTU) measured in the Feather River in 2017............................................... 47
Figure 10. Streamflow(cfs) and available turbidity(NTU) data for the High Flow Channel in
2006 and 2017..............................................................................................................................48
List of Tables
Table 1. Release requirements under all releases (especially high releases) are subject to
consultationwith the USACE......................................................................................................... 14
Table 2. Special status anadromous species that may occur within the Action Area ................. 29
Table 3. Critical periods for federally listed species present with the Action Area...................... 30
Table 4. Potential adverse effects from the Oroville Spillway Incident Response on Protected
Species........................................................................................................................................... 45
Table 5. Observed and extrapolated numbers of special status species stranded in wet pools
during the Oroville Spillway Incident and resulting response actions.......................................... 56
Table 6. 2017 FRFH releases of Spring-and Fall-run Chinook Salmon......................................... 60
V
EXECU7 1VE SUMMARY
This Biological, Critical Habitat, and Essential Fish Habitat Assessment (BA) has been prepared
by the California Department of Water Resources (CDWR), designated as the non-federal
representative for the Federal Energy Regulatory Commission (FERC), to support emergency
Section 7 consultation between the Federal Energy Regulatory Commission (FERC) and the
National Marine Fisheries Service (NMFS) on the effects of the Oroville Spillway incident
response during winter 2017 on Endangered Species Act (ESA) listed anadromous fish. It
documents the effects the response to the Oroville Spillway Incident may have had on
threatened or endangered species and Critical Habitat (CH) regulated by NMFS as well as
Essential Fish Habitat (EFH) that may occur in the Action Area.
The BA consultation has been prepared with the following objectives; 1) determine whether
any federally endangered or threatened species managed by NMFS, and known to exist within
the Action Area, were adversely affected by the response to the Oroville Spillway Incident, 2)
determine if any designated Critical Habitat was adversely modified by the response to the
incident, and 3) determine if designated Chinook Salmon EFH was adversely affected by the
response to the incident. Endangered or Threatened Species considered in this BA include
California Central Valley(CCV) Steelhead (Oncorhynchus mykiss), Central Valley Spring-run
Chinook Salmon (Oncorhynchus tshawytscha), Sacramento Winter-run Chinook Salmon, and
North American Green Sturgeon southern Distinct Population Segment (Acipensermedirostris).
The Action Area extends from the upstream limit of anadromy at the Fish Barrier Dam in
Oroville, California to the confluence of the Feather and Sacramento rivers near Verona. The
Feather River Fish Hatchery was included in the Action Area because Spring-run Chinook
Salmon and CCV Steelhead reared at this facility are included in the Evolutionary Significant
Units for their respective species. Four potential actions taken in response to the Oroville
Spillway Incident that may have adversely affected protected species, Critical Habitat, and
Essential Fish Habitat include 1) use of the Emergency spillway and damaged FCO spillway, 2)
material removal in the Thermalito Diversion Pool, 3) four periods of rapid-flow ramping
resulting from Flood Control Outlet operations, and 4) activities undertaken at the Feather
River Fish Hatchery.
Fine suspended sediment introduced into the Lower Feather River as a result of the operation
of the Emergency Spillway and removal of material from the Thermalito Diversion Pool was
likely to adversely affect Spring-run Chinook Salmon and CCV Steelhead juveniles. Rotary screw
trap data from prior years indicate that a large proportion of Spring-run Chinook Salmon
juveniles had likely migrated out of the Action Area prior to the Oroville Spillway Incident.
However, any juvenile Spring-run Chinook Salmon and CCV Steelhead that remained in the
Lower Feather River to rear during the elevated turbidity may have experienced reduced
growth as a result of impaired reactive distance to prey, potential effects to respiratory
function, and reduced tolerance to disease. Any Winter-run Chinook that may have been
rearing in the lower Feather River would have been so far downstream from the primary impact
vi
area they would have easily been able to leave the river if conditions were unsuitable.
Therefore, fine suspended sediment (increased turbidity) was not likely to adversely affect
Winter-run Chinook salmon.
Fine suspended sediment at the levels observed during Green Sturgeon spawning, egg
incubation, and rearing was not likely to adversely affect adults, eggs, larvae, or juveniles.
Furthermore, sustained flow pulses>40,000 cubic feet per second (cfs) following the incident
may have transported fine suspended sediment mobilized during the incident and alleviated
potential impacts to Green Sturgeon spawning and rearing habitat. Green Sturgeon Critical
Habitat may have been affected, but was not likely adversely effected or modified by the
response to the Oroville Spillway Incident.
Rapid flow ramping was likely to adversely affect CV Spring-run Chinook Salmon and CCV
Steelhead. Previous juvenile monitoring from Feather River screw traps suggests that most
Spring-run juveniles had already migrated out of the Action Area when the four ramping
periods occurred. Stranding surveys also revealed low mortality of juvenile and adult salmonids
in wet pools and most of these pools were reconnected to the main channel with subsequent
high flows. Fish residing in pools that did not dry out may have actually obtained a growth
benefit from access to these flooded habitats. The great majority of salmonids encountered
during stranding surveys were found in wet pools and likely suffered no adverse effect from the
rapid flow ramping events and likely emigrated safely when flows later increased and
reconnected isolated pools with the river. However, based on the timing of the Oroville
Spillway Incident,the four rapid flow ramping events were likely to adversely affect Spring-run
Chinook Salmon and CCV Steelhead due to observed lethal stranding and unobserved mortality
expected from avian predation and desiccation in fast drying pools.
No Green Sturgeon were detected using eDNA sampling in isolated pools and no Green
Sturgeon were observed in stranding surveys. Thus, rapid flow ramping was not likely to
adversely affect Green Sturgeon of any life-stage.
Adverse effects of the Oroville Spillway Incident response on juvenile CCV Steelhead and CV
Spring-run Chinook Salmon at the Feather River Fish Hatchery (FRFH) were limited due to
management actions taken to ensure survival of eggs and juveniles while they were reared in
the FRFH and after they were moved to the Thermalito Annex (Annex). Efforts to mitigate
potential water quality concerns were so successful that significantly more CCV Steelhead
yearlings and Fall-run Chinook Salmon smolts were released in 2018. Some CCV eggs and
juvenile CV Spring-run may have been affected, but were not likely adversely affected from
increased turbidity and additional handling experienced at the hatchery.
There was no destruction, adverse modification, or adverse effect to Critical Habitat or Essential
Fish Habitat of CCV Steelhead, CV Spring-run Chinook Salmon, CV Winter-run Chinook Salmon
or sDPS Green Sturgeon from the response to the Oroville Spillway Incident.
Vii
LIST OF ACRONYMS
Annex Thermalito Annex
BA Biological and Essential Fish Habitat Assessment
CalOES California Office of Emergency Services
°C Degrees Celsius
CCV California Central Valley
CDFW California Department of Fish and Wildlife
CDWR California Department Water Resources
CESA California Endangered Species Act
CFR Code of Federal Regulations
cfs Cubic Feet Per Second
cy Cubic Yards
CV Central Valley
CVRWQCB Central Valley Regional Water Quality Control Board
Delta Sacramento-San Joaquin River Delta
DO . Dissolved Oxygen
DSOD California Division of Safety of Dams
DPS Distinct Population Segment
EFH Essential Fish Habitat
ESA Endangered Species Act
ESU Evolutionary Significant Unit
OF Degrees Fahrenheit
viii
FCO Flood Control Outlet
FEMA Federal Emergency Management Agency
FERC Federal Energy Regulatory Commission
FL Fork Length
FMP Pacific Coast Salmon Fishery Management Plan
FR Federal Register
FRFH Feather River Fish Hatchery
ft Feet
WFC High Flow Channel
WPP Hyatt Powerplant
LFC Low Flow Channel
LSNFH Livingston Stone National Fish Hatchery
LWD Large Woody Debris
M Meters
MAF Million Acre-Feet
Mg/I Milligrams per Liter
Mg/d Million gallons per day
Mi Miles
MSA Magnuson-Stevens Fishery Conservation and Management Act
NHPA National Historic Preservation Act
NMFS National Marine Fisheries Service
NOAA National Oceanic and Atmospheric Administration
NTUs Nephelometric Turbidity Units
ix
PG&E Pacific Gas and Electric
RM River Mile
RST Rotary Screw Trap
sDPS Southern Distinct Population Segment
SHPO State Historic Preservation Officer
SR HGMP Spring-run Hatchery and Genetic Management Plan
SWP State Water Project
SWRCB State Water Resources Control Board
TAO Thermalito Afterhay Outlet
TDP Thermalito Diversion Pool
USACE U.S. Army Corps of Engineers
USFWS U.S. Fish and Wildlife Service
USGS U.S. Geological Survey
x
1 INTRODUCTION
1.1 Purpose and Objectives
This Biological, Critical Habitat, and Essential Fish Habitat Assessment (BA) has been prepared
by the California Department of Water Resources (CDWR),to support emergency Section 7
consultation between the Federal Energy Regulatory Commission (FERC) and the National
Marine Fisheries Service (NMFS) on the effects of the Oroville Spillway Incident response during
winter 2017 on Endangered Species Act (ESA) listed anadromous fish. It documents the effects
the response to the Oroville Spillway Incident may have had on threatened or endangered
species and Critical Habitat regulated by NMFS as well as Essential Fish Habitat (EFH) that may
occur in the Action Area. This BA has been prepared in compliance with legal requirements set
forth under Section 7 of the ESA of 1973 (U.S. Government Code ([USC] Title 16, Section 1536
[16 USC 1536]) and the (Magnuson-Stevens Fishery Conservation and Management Act (MSA).
The emergency consultation addresses potential impacts of the Oroville Spillway Incident
response on anadromous fishes listed under the ESA within the Action Area. The Feather River
lies within United States Geological Survey(USES) hydrologic unit 18020106. The Action Area
encompasses the Lower Feather River from the Fish Barrier Dam, which is the current upstream
limit of anadromous fishes, to the confluence of the Feather and Sacramento rivers near
Verona, CA (Figure 1),
y
r
RI' r
jp
f,
y
" 11:
M �
r
Low Flaw Channel Emergency Spillway N
High Flow Channel Main Spillway
4 3.75 7,5 15 22.5 30
K'al4meters
Figure 1. Location of the Action,area. Only the Feather River downstream to the confluence with the
Sutter Bypass is shown on the map. The Feather River confluence with the Sacramento River is
approximately eight miles downstream from where it meets the Sutter Bypass.
The BA consultation has been prepared with the following objectives:
• To determine whether federally protected species managed by NMFS, and known to
exist within the Action Area, were adversely affected by CDWR's response to the
Oroville Spillway Incident.
• To determine if designated Critical Habitat was adversely affected or modified by the
CDWR's response to the Oroville Spillway Incident.
• To determine if designated Chinook Salmon EFH was adversely affected or modified by
CDWR's response to the Oroville Spillway Incident.
1.2 Threatened and Endangered Species
Endangered and Threatened Species considered in this BA:
• California Central Valley(CCV) Steelhead Distinct Population Segment (DPS)
(Oncorhynchus mykiss) (Federal Threatened; 79 Federal Register [FR] 20802)
• Central Valley(CV) Spring-run Chinook Salmon Evolutionary Significant Unit (ESU)
(Oncorhynchus tshawytsha) (Federal Threatened; 79 FR 20802)
• North American Green Sturgeon southern DPS (sDPS) (Acipensermedirostris) (Federal
Threatened; 79 FR 20802)
• Sacramento River Winter-run Chinook Salmon ESU (Oncorhynchus tshawytsha) (Federal
Endangered; 58 FR 33212-33219)
1.3 Critical Habitat and EFH in the Action Area
Critical Habitat is defined as specific locations within the geographical area occupied by the
species that contain physical and biological features essential to the conservation of the species
and which may require special management considerations or protections(ESA Section
3(5)(A)(1)). The primary physical and biological features of Critical Habitat include freshwater
rearing habitat, freshwater migration corridors, and spawning habitat. The action area serves
as spawning, rearing, and migration habitat for CCV Steelhead, CV Spring-run Chinook Salmon,
and sDPS Green Sturgeon and non-natal rearing habitat for Sacramento River Winter-rein
Chinook Salmon.
Chinook Salmon are subject to the MSA and regulated by the Pacific Coast Salmon Fishery
Management Plan (FMP). The FMP includes designation of EFH and requires consultation with
NMFS if a project or action would potentially affect EFH. EFH applies to Pacific salmon and
other commercial fish species and is defined as the aquatic habitat necessary for spawning,
3
breeding, feeding, or growth to maturity. Important components of Pacific salmon EFH are
substrate; water quality; water quantity, depth, and velocity; channel gradient and stability;
food; cover and habitat complexity; space; access and passage; and habitat connectivity. The
Action Area is within the EFH for Fall-run Chinook Salmon, Spring-run Chinook Salmon, late Fall-
run Chinook Salmon, and Winter-run Chinook Salmon. Critical Habitat and EFH within the
Action Area are described in greater detail in Chapter 5.
4
2 ENVIRONMENTAL BASELINE
The Feather River below Oroville Dam supports populations of multiple anadromous fishes that
are federally listed as threatened or of special concern, including CCV S,teelhead, CV Spring-run
Chinook Salmon, CV Fall/Late fall'-run Chinook Salmon, and sDP,S Green Sturgeon,. These species
are entirely dependent on flow releases to the Lower Feather River from, Oroville Dam, Non-
natal juvenile Winter-run Chinook Salmon are also expected to seasonally rear in the lower-
most reaches of the Feather River. Additionally, the Feather River Fish Hatchery (FRFH) was
constructed in 1967 to mitigate for CV Spring-run, CV Fall-run, and CCV Steelh;ead production
lost due to the construction of Oroville Dam, Currently,the FRFH produces Spring- and Falll-run
Chinook Salmon as well as CCV Steelhead.
2.1 Location of Facilities and General Description of the
Watershed
The Feather River is the largest tributary of the Sacramento River located in California's CV
(Figure 2). The —9,324 km2 watershed above Oroville Dam primarily drains the western slope of
the Sierra Nevada north of the Yuba River watershed and is bounded by Mount Lassen to the
north and the Diamond Mountains to the north east, with 59%of the watershed below
snowline (Koczot et al. 2005). Elevations in the watershed range from 10,463 ft (2774 m) atop
Mount Lassen, 150 ft at Oroville, and 25 ft (15 m) at the confluence with the Sacramento River.
The four forks of the Feather River (West Branch, North, Middle, and South) all flow into an arm
of Lake Oroville and are captured by Oroville Dam, resulting in 8%of total reservoir capacity in
California. Below Oroville Dam,the Feather River is joined by Honcut Creek, the Yuba River,
and the Bear River before joining the Sacramento River near Verona.
5
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Figure 2. The Feather liver watershed,Sacramento-San Joaquin delta, and San Francisco Bay.
The lower Feather River flows for approximately 67 Rhos below the Fish Barrier Dam to the
confluence with the Sacramento River and is the section of river accessible to anadromous
fishes. The Feather River and its floodplain historically supported dense riparian woodland.
While much of the CV upland and foothills were historically covered by sparsely wooded
grassland's, pre-settlement riparian zones supported dense, multistoried stands of broadleaf
trees, including valley oak (Quercus lobata), Fremont cottonwood (Populus fremontil), western
sycamore (Platanus racernosa), willow (Salix spp.), Oregon ash (Froxinus latifolia), box elder
(Acer negundo), California black walnut (Juglans californica), and other species (Thompson
1961, 1980; Conard et al. 1980; Holland and Keil 1995). The amount of riparian habitat along
the Lower Feather River has been substantially reduced as a result of gravel dredging and
mining, bank protection, riparian vegetation removal, flood control levees, agricultural and
residential development, and flow regulation (Buer et al. 2004)..
6
The Orovi Ile Facilities and the Pacific Gas and Electric (PG&E) facilities have made inaccessible a
substantial amount of historical habitat for anadromous fishes (NMFS 2016). Historically, CV
Spring-run Chinook Salmon and CCV Steelhead ascended all four branches of the Feather River
(NMFS 2016). CV Spring-run Chinook Salmon were able to ascend the longest distance in the
North Fork of the Feather River; they ascended several miles upstream from what is now Lake
Almanor(Yoshiyama et al. 2001). For sDPS Green Sturgeon, Mora et al. (2009) estimated that
Oroville Dam blocks access to 10 ± 2.5 RM of relatively high value habitat.
The upper watershed is comprised primarily of coniferous forest, including portions of three
national forests (Plumas, Lassen, and Tahoe). Land uses include logging and recreation. In
lowland reaches, land use is dominated by agriculture with areas of urban development. The
lower watershed has been extensively levied for flood protection, navigation, and to facilitate
the movement of mining sediments out of the main channel.
Oroville Dam was completed in 1968 as the centerpiece of the State Water Project (SWP).
Oroville Reservoir has the second largest storage capacity of California reservoirs at^3.5 million
acre-feet. In addition to water storage and conveyance for use in the SWP, the dam and
associated facilities generate power and provide flood protection for downstream
communities. Additionally, the reservoir provides a variety of recreational opportunities for the
public. In general, winter and spring runoff is stored in Oroville Reservoir and water is released
in late spring and summer for diversion at the South Sacramento-San Joaquin River Delta
(Delta) pumps and to maintain water quality conditions in the Delta.
Water discharged into the Lower Feather River begins in Oroville Reservoir(Figure 1). From
there, water is released into the TDP directly below Oroville Dam. Water is most often released
from Lake Oroville via HPP during normal flow conditions. When reservoir inflows require
greater discharge, water is released from the FCO Spillway into the TDP. A small volume of
water can also be released from the river valve, but this action is almost exclusively undertaken
to meet downstream temperature criteria. Water can also enter the TDP from the Emergency
Spillway; however, this has only happened once since Oroville Dam was constructed and that
was duringthe incident described in this document. From the TDP, the majority of water is
diverted into the Thermalito Complex which includes the Thermalito Forebay, Thermalito
Afterbay, and associated power plants, where some of the water is diverted for local use before
reentering the lower Feather River at the TAO. The remaining flow is released into the main
channel of the lower Feather River,the LFC.
2.2 Lower Feather River
The fish habitat in the Lower Feather River below the Fish Barrier Dam is generally divided into
the LFC and HFC based on differences in flow and habitat conditions. The LFC is an 8.1 river
mile (RM) section between the Fish Barrier Dam and the TAO where discharge is mostly stable
at 600-800 cfs, except under flood conditions or when flow increases are needed for river
temperature management. The HFC is a 59 RM section between the TAO and the confluence
7
with the Sacramento River. The flows and temperatures in the HFC are greater and fluctuate
more, relative to the LFC. (Seesholtz et al. 2004). The LFC in comparison to the HFC has a higher
gradient, cooler summer and fall water temperatures, and a lower, more stable flow level.
Native fishes, particularly anadromous salmonids, are observed more frequently in the LFC
while non-native fishes including piscivorous Striped Bass (Morone saxatilis) and black bass
(Micropterus spp.) tend to be observed more frequently in the HFC (Seesholtz et al. 2004). Both
reaches have degraded native fish habitat conditions as a result of anthropogenic activities
including bank protection, gravel mining and dredging, loss of bed material recruitment,
riparian vegetation removal, diversions,flow regulation, and flood control (Buer et al. 2004;
NMFS 2016).
The LFC and HFC are confined by levees that limit connectivity between the Lower Feather
River and its floodplain and simplify and narrow channel morphology. The width between the
confining levees varies, ranging from approximately the same as the active river channel in
some locations to several miles in others (Buer et al. 2004). The Feather Rivers historical
floodplains have been developed for agricultural and residential uses. The lack of bed material
recruitment to the Lower Feather River due to capture by Lake Oroville has resulted in a
sediment starved and armored riverbed (NMFS 2016). The substrate in the Lower Feather River
has become armored by cobbles and boulders, which has negatively impacted anadromous
salmonid spawning habitat (NMFS 2016). To address the lack of natural gravel recruitment in
the Lower Feather River, CDWR added 8,300 cyof salmonid spawning gravel to-the upper LFC in
2014 and an additional 5,000 cy of salmonid spawning gravel to the same section of river in
2017.
The massive amount of hydraulic mining debris that was deposited on the valley floor along the
Feather River has had negative impacts on channel morphology, resulting in reduced habitat
quantity and quality for native fishes, particularly anadromous salmonids. The Lower Feather
River has become entrenched in the mining debris, with reduced bank erosion and meander
rates (Buer et al. 2004). Sank erosion has been reduced due to coarse dredge tailings in the
upper reach and incision in hydraulic mining slickens in the lower reach (Buer et al. 2004).
Decreased hank erosion has impacts on meander rates, riparian succession, and sediment
recruitment, particularly gravel recruitment for salmonid spawning riffles (Buer et al. 2004).
Reduced meander rates have also had direct impacts on stream mesohabitat diversity, as
natural meandering is the primary action creating multiple channels, side channels, islands,
point bars, alternating riffles and pools, and driving recruitment of large woody debris (LWD)
(Buer et al. 2004). Meandering directly contributes to the creation of high quality anadromous
salmonid habitat; therefore, reduced meander rates result in a reduction in anadromous
salmonid habitat quality(Buer et al. 2004).
The Oroville Facilities operations have substantially altered the flow regime in the LFC and HFC
compared to pre-dam conditions. The primary function of Oroville Dam is to store winter and
spring runoff for later release into the lower Feather River for SWP water uses. This flow
regulation has resulted in changes to the yearly, monthly, and daily stream flow distributions,
8
bankfull discharge, flow exceedance, peak flow, and other hydraulic characteristics (Suer et al.
2004). Mean monthly flows in the LFC are 5 to 38% of pre-dam levels, partially as a result of
diversion into the Thermalito Complex (Sommer et al. 2001). Mean total flow below the TAO is
lower than historical levels during February through June but higher from July through January,
flattening the annual hydrograph (Sommer et al. 2001.). Minimum instream flows in the LFC
and HFC are substantially reduced compared to average monthly pre-dam flows (NMFS 2016).
The pre-dam bankfull discharge (two-year recurrence interval flow event) was approximately
65,000 cfs for the Feather River at Oroville; in contrast, the bankfull discharge post-dam is
approximately 2,000 cfs for the LFC and 26,000 cfs for the HFC (NMFS 2016). Other flow
frequencies and durations have changed pre- and post-dam as well; for example,the 10-year
recurrence event has decreased from 160,000 to 75,000 cfs and the 50-year event from
240,000 to 180,000 cfs (NMFS 2016).
The majority of Chinook Salmon and CCV Steelhead spawning occurs in the LFC (NMFS 2016).
CV Spring-run Chinook Salmon spawning occurs in the LFC, with the majority of spawning
occurring in the three miles below the FRFH (NMFS 2016). The majority of CCV Steelhead
spawning has been observed to occur in the LFC with most spawning occurring in the upper
mile of the LFC (Hartwigsen and Reid 2009). However, some CCV Steelhead redds were also
observed in the HFC in 2003 and other years. Similar to spawning habitat, the majority of
rearing Chinook Salmon and CCV Steelhead are observed in the LFC (Mercer 2012). Most
rearing Chinook Salmon and CCV Steelhead were observed in riffle and glide habitats; however,
these habitats are rare in the lower Feather River and are interspersed within extensive low
velocity pool habitat (Cavallo et al. 2003).
Southern DPS Green Sturgeon have been observed in the Lower Feather River up to the Fish
Barrier Dam (FBD), including the first documented spawning of the species within the LFC area
during 2017, approximately% mile below the FBD. Before 2017, sDPS Green Sturgeon
spawning had only been known to occur in the HFC nearthe TAO (Seesholtz et al. 2015). This
documented spawning was in 2011, designated a wet year like 2017, suggesting that sDPS
Green Sturgeon spawning in the Lower Feather River may be more common in wet years.
DIDSON surveys estimated 21-28 sturgeon (green and white) in the Lower Feather River in 2011
and at least 3 to 4 sturgeon in 2012, which was a drier year that did not have high flow events,
supporting this hypothesis (Seesholtz et al 2015). Investigations have determined that there
are 12 deep pools from the Fish Barrier Dam (RM 67) to RM 54 with depth, velocity, and
substrate that are attractive to sDPS Green Sturgeon (NMFS 2016). The alteration of the Lower
Feather River flow regime by the Oroville Facilities is one of the most problematic issues for
sDPS Green Sturgeon because sDPS Green Sturgeon appear to use winter and spring flow pulses
as environmental cues for migration and spawning (NMFS 2016). The capture of winter and
spring storms as well as spring snow melt by Lake Oroville in many years inhibits the
environmental cues that these flows would provide to initiate sDPS Green Sturgeon migration
into the Lower Feather River (NMFS 2016). More significantly, there is a boulder weir migration
barrier for sDPS Green Sturgeon at Sunset Pumps (NMFS 2016). There are also many
9
unscreened water diversions in the Lower Feather River that potentially provide a large
entrainment risk and thus mortality for [arvaland juvenile sDPS Green Sturgeon (NMFS 2016).
The lower Feather River downstream of the Fish Barrier Dam provides habitat for a wide variety
of freshwater and anadromous fish species. In addition to CCV Steelhead and Chinook Salmon,
native fish species observed in the lower Feather River include Pacific Lamprey (Entosphenus
tridentatus), River Lamprey (Lampetra ayresi), Sacramento Pikeminnow(Ptychocheilus grandis),
Sacramento Sucker (Catostomus occidentalis), Tule Perch (Hysterocarpus traskii), Hardhead
(Mylophardon conocephalus), Sacramento Splittail (Pogonichthys macrolepidotus), Green
Sturgeon (Acipenser medirostris), White Sturgeon (Acipenser transmontanus), Speckled Dace
(Rhinichthys ocsculus), Hitch (Lavinia exilicauda), Prickly Sculpin (Cottus asper), and Riffle
Sculpin (Cottus gulosus)(Seesholtz et al. 2004, Bilski and Kindopp 2009, Moyle 2002). Non-
native species observed in the Lower Feather River include American Shad (Aloso sapidissima),
Striped Bass (Moronesaxatilis), Black Crappie (Pomoxis nigromaculatus), White Crappie
(Pomoxis annularis), Bluegill (Lepomis macrochirus), Redear Sunfish (Lepomis microlophus),
Warmouth (Lepomis gulosus), Green Sunfish (Lepomis cyanellus), Pumpkinseed (Lepomis
gibbosus), Mosquito Fish (Gambusia affinis), Fathead Minnow (Pimephales promelas), Golden
Shiner(Notemigonus crysoleucas), Largemouth Bass (Micropterus salmoides), Smallmouth Bass
(Micropterus dolomieu), Brown Bullhead (Ameiurus nebulosus), Channel Catfish (Ictalurus
punctatus), White Catfish (Ameiurus catus), Wakasagi (Hypomesus nipponensis), and Common
Carp (Cyprinus carpio), (Seesholtz et al. 2004, Bilski and Kindopp 2009, Moyle 2002).
2.3 Feather River Fish Hatchery
The FRFH was constructed to mitigate for the loss of salmonid spawning habitat above Oroville
Dam. The FRFH is located along the north embankment of the Lower Feather River,
approximately four RMs downstream from the Oroville Dam on property owned by CDWR in
Oroville, CA, Butte County(near latitude N 39°31'5.20" and longitude W 121°33'11.62"; Figure
1). Freshwater is diverted to the FRFH from the Lower Feather River at the Thermalito
Diversion Dam at a maximum flow rate of about 110 cfs or 71 million gallons per day (mg/d).
Freshwater is gravity fed to an aeration tower and subsequently delivered throughout the
facility. Typically, more freshwater is withdrawn from the lower Feather River than can be used
at the FRFH due to design pressure requirements. The minimum necessary flow rate to
maintain standard operating conditions is estimated to be 40 cfs, during which time,
approximately 70 cfs of aerated water is discharged back into the Lower Feather River; flow-
through water not used in operations is only aerated water and contains no chemicals or
wastes. FRFH operations are continuous and only halted for maintenance approximately once
every five years.
Flow rates vary depending on the number of fish present at the FRFH. During the spawning
season, when the fish [adder is in use, freshwater from the fish ladder is sent into a gathering
tank and four holding tanks before discharge into the lower Feather River. Direct discharges
10
from the gathering and holding tanks only contain fish feces because the broodstock fish are
not fed or treated with chemicals.
Wastewater from the main FRFH building, rearing channel, and rearing raceways is mixed
together and sent to one of three locations:
(1) the Lower Feather River(this valve is always locked and only opened for emergency
situations),
(2) a sump basin, and/or
(3) two settling basins (approximately 300-ft long by 30-ft wide by 15-ft deep).
The two settling basins are located near the banks of the lower Feather River and contain
square concrete overflow boxes in each basin to allow for a direct discharge into the lower
Feather River. The settling basins are constructed in permeable gravels that have large
hydraulic conductivities and percolation rates, allowing FRFH wastewater to enter the lower
Feather River via seepage. In normal operating conditions, water from the FRFH building
wastewater is sent into a sump basin, subsequently discharged into the settling basins, and,
when the settling basins are at their design volume capacity, overflows directly into the lower
Feather River. If the pump in the sump basin fails, FRFH wastewater from the sump basin
overflows into the lower Feather River. FRFH wastewater from two raceways located near the
western section of the FRFH is discharged directly to the facility's southwest settling basin and
does not enter the sump basin.
The Annex is located adjacent to the western shoreline of the Thermalito Afterbay on property
owned by CDWR and operated by CDFW, in Oroville, California, Butte County (near latitude
N39028'43.94"and longitude W 12104'17.26").
The Annex is supplied with groundwater from five groundwater extraction wells owned by
CDWR. Thus, the Annex is not influenced by water quality in the lower Feather River.
Groundwater can be pumped from any of the groundwater wells, which changes based on
CDWR operations. Freshwater flows through a passive aeration tower before entering the
Annex's four parallel-operated raceways; each raceway is 10-ft wide, 4-ft deep, and 600-ft long.
Subsequently, the Annex wastewater enters two sump basins before being pumped to the
Thermalito Afterbay using a pump float system; each sump basin has two pumps that operate
according to required hydraulic removal rates. The estimated maximum discharge flow rate
into the Thermalito Afterbay is about 25 cfs or about 16 mg/d. Other ancillary Annex
components include a permanent residential mobile home, a domestic wastewater holding
tank, an office building, and a maintenance building.
Fish in the fry stage of the salmonid life cycle are occasionally reared at the Annex, typically
from late December through lune of the following year. Transport of salmonids to and from
the FRFH and the Annex occurs as the need arises, but the majority of juvenile rearing occurs at
the FRFH. The Annex is mainly utilized as back-up support for the mitigation and enhancement
functions of the FRFH.
11
2.4 Existing Measures to Protect Biological Resources
2.4.1 Standard Operations for Biological Protection
In 1983, an agreement between CDWR and CDFW entitled, "Agreement Concerning the
Operation of the Oroville Division of the State Water Project for Management of Fish and
Wildlife," outlining criteria and objectives for flow and temperature in the LFC and between
TAO and Verona was signed and is described in the next two sections.
2.4.2 Flow
The minimum flow into the LFC does not change based on water year type and is set at 600 cfs
(1983 Agreement). This is the combined flow from the Thermalito Diversion Dam, the
Thermalito Diversion Dam Power plant, and the Feather River Fish Hatchery pipeline. Any
change to this minimum flow must be agreed to by CDWR and CDFW.
The 2004 NMFS Operation, Criteria and Plan (OCAP) Biological Opinion also established ramping
criteria for the LFC. The rate of decrease cannot exceed 300 cfs per 24 hours when flows are
between 2500 and 600 cfs. Additional ramp-down rates include 500 cfs/24 hours when flows
are between 3500 and 2501 cfs and 1000 cfs/24 hours when flows are between 5000 and 3501
cfs. Note that these ramp-down rates are for periods outside of flood management operations
and to the extent controllable within flood management operations.
Flow criteria below the TAO are as follows:
Minimum
1,700 cfs October-March..
1,000 cfs April-September.
*If runoff from previous April-July¢1,942,000 AF, flows can be reduced to 1,200 cfs October-
February and 1,000 cfs for March. Additionally, if the April 1 forecast indicates Oroville
Reservoir will drop below elevation 733, flows to the river can be cut up to an additional 25%,
commensurate with reductions in flow for agricultural uses.
Spawnin.g Flows
Spawning flows are typically 1200-2,500 cfs October 15- November 30. If 2,500 cfs is exceeded
during this time; then flow cannot go 500 cfs below the average highest 1-hour flow (to prevent
spawning in locations that can potentially become dewatered).
In addition, flow reductions should not be greater than 200 cfs during any 24-hour period,
except for flood management, failures, or other emergency conditions and flows should remain
stable during the peak of spawning season for Fall-run Chinook Salmon. CDWR operates to both
the 1983 Agreement and the 2004 NMFS Biological Opinion forthe Long-Term Operational
Criteria and Plan flow standards under normal operating conditions. Flows are increased at a
12
rate of 5000 cfs/hour regardless of flow during the previous hour. This ramping criterion is
suspended when Lake Oroville storage is above 2.78 million acre-feet (MAF; i.e. flood
conditions).
2.4.3 Temperature
Temperatures in the FRFH and Robinson Riffle are managed by monitoring the water
temperature coming into the Diversion pool. Temperature criteria at FRFH is as follows:
48-56°F September
47-55°F October-November
557 December-March
47-557 April-May(557 for last half of May)
52-607 June 1-15
58-647 June16-August 15
54-627 August 16-31
NMFS also has their own criteria established for CCV Steelhead and Spring-run Chinook Salmon
which is documented in a biological opinion on the effects of the Central Valley Project and
SWP on CV Spring-run Chinook and CCV Steelhead as a reasonable and prudent measure.
CDWR is required to regulate water temperatures at Robinson's Riffle in the LFC from June 1-
September 30. Temperatures must be less than or equal to 657 on average each day.
2.5 Modeled Nater Operations
Expected operations without the Oroville Spillway Incident were modeled for the period from
February 7- May 31, 2017 with a release schedule in accordance with the 1970 USACE's Report
on Reservoir Regulation for Flood Control -Oroville Dam and Reservoir. The maximum release
under this no-incident scenario was 150,000 cfs with a total of 5,885,942 acre-feet of water
released (Figure 3). The change in release rates is as follows in any two-hour period:
• Increase no more than 10,000 cfs
• Decrease no more than 5,000 cfs
13
160000 -
Actual
140000 I1 — — 150K Scenario
II
I1
120000 I�
II
II
II
100000 r
r
I
I
80000
I
1
60000 I
1 I
40000
I R
20000
I I
7
i
0
n n n n n n n n n n n n n n n n n n
.moi CO i N H opo Ln N rn Ln N rn LD m a n
N N m m Ln
N N m m M Ln Ln N Ill
Date
Figure 3. Releases from Oroville Dom between February 1 and May 31, 2017(solid line)and modeled
flows assuming the Oroville Spillway Incident has not occurred(150k scenario-dashed line).
Criteria for simulating no-incident flow releases are shown in Table 1.
Table 1. Release requirements under all releases(especially high releases)are subject to consultation
with the USACE and would depend on real-time conditions.
Actual or Forecast Inflow Flood Control Space Used,AF Required Releases, cfs
(whichever is greater), cfs
0- 15,000 0-5,000 Power Demand
0- 15,000 Greater than 5,000 Inflow
15,000-30,000 0-30,000 Lesser of 15,000 or max inflow
0-30,000 Greater than 20000 Maximum inflow for flood
30,000- 120,000 - Lesser of max inflow or 60,000
120,000- 175,000 - Lesser of max inflow or 100,000
Greater than 175,000 - Lesser of max inflow or 150,000
14
2.5.1 ed ad Movement
In wet years, bedload movement resulting from high flow releases from Oroville Dam is a
common occurrence. The following describes a sediment transport analysis related to the
Oroville Spillway Incident to demonstrate bed load movement under the modeled outflow
scenario and as a result of emergency operations. The overall approach was to use existing
available information and compare two hydirograph scenarios on their effect on bedload
transport in a gravel augmentation area. The first scenario was the actual flow released from
the spillway, while the second scenario was a modeled hypothetical release of 150,000 cfs
followed by three smaller peaks (Figure 3).
A cross section based assessment of bedload transport was conducted using data from a 2003
HEC-RAS model developed for the Feather River (Figure 4). In addition to the assumptions
inherent in that model it was assumed that as-built conditions for gravel augmentation were
similar to the available cross section geometry in the model. The closest cross section at RM
65.93 was chosen, since it is approximately 1885 ft downstream of the Table Mountain
Boulevard Bridge, and approximately midway through the spawning area of interest (Figure 5).
30,0
250
F 200
0
150
uJ 100
50
0
0 1000 2000 3000 4000 5000 6000 7000
Distance (ft)
Figure 4. Cross section(station 65.93 in the HEC-RAS model)used in the sediment transport analysis,
Source: MWH 2003,
15
M
I,
�i
6
Figure 5. Location of 2014 gravel augmentation area(blue polygons)in the Feather River. The redline is
the approximate location of the crass section. The Fish Barrier Dana and Thermalito Diversion Dam are
also visible in the image.
Two different analyses were performed using this data. First, shear stress at the selected cross
section was exported from the model and a rating curve of shear stress versus flow developed.
A trend was fitted to the rating curve, and then used along with the two hydr®graphs to
develop a series of shear stress versus flow. Next, the cumulative excess shear stress was
calculatedfor the series, using the critical shear stress for the median grain size (1350) as
reference shear stress value. The D50 is 32 mm, and the corresponding critical shear stress is
0.43 Ib/ft2 (20.5 Pa) (Fischenich 2001).
The second analysis utilized the BAGS model for bedload transport (Pitlick et al. 2009). The
cross-section geometry, an estimate of the bed/energy slope, and estimates of friction were all
derived from the HEC-RAS model (MWH 2003). The sediment distribution was assumed to
follow the Anadromous Fisheries Restoration Programs gradation for spawning gravels, which
should be a good representation of the gravel at the cross-section since the area was
augmented with quality spawning gravel in 2014. Once a bedload rating curve was developed a
trend was fit and then used along with both flow scenarios to estimate bedload transport for
each time step in the hydrograph. The cumulative bedload transport was calculated for both
scenarios.
16
The cumulative excess shear stress is initially lower for the actual flow scenario compared to
the 150,000 cfs scenario (Figure 6). By late March, the cumulative excess shear stress becomes
higher by about 29 IbS/ft2 for the actual flow scenario, and by June the actual flow scenario had'i
an excess of—90 lbS/ft2 (-4,300 Pa).
400
350
300
_0001
'n 250
M
200
—Actual
150
150K Scenario
100
50
E 0
N W
NJ
0) n o Ln
o 0
Nj
1- 2
Ij I-j
Figure6. Cumulative excess shear stress for the Dso for both flow scenarios.
Since most bedload rating curves are founded on excess shear stress, the cumulative change in
bedload transport exhibited a similar pattern. The 150,000 cfs flow scenario would have moved
more bedload than the actual flows up to approximately late March (Figure 7). However, from
late April through June the actual scenario has higher cumulative bedload transport.
17
4.50E+08
4.00E+0£3
3.50E+08
3,00E+08
_ 2.50E+08
Actual
6 2.00E+08
15010 Scenario
ca 1.503+08
1.00E+08
5.00E+07
0.00E+00
w Uj 41. Ln
N LD
Cn LM Ln
ry n ra 4
c o c7 1 10 �
Figure 7. Cumulative bedload transport far bath flaw scenarios.
First hand observations by CRWR nate that most of the restoration gravel placed in 2014 at the
crass section used in this analysis was mobilized during the high flaws of 2017. Other riffle
locations were also changed from either additions or depletions of gravel. However, because
the flow scenarios are so similar,there would have been similar bedload movement without
the spillway failure; therefore,this information is provided as background and is not considered
relevant for the effects analysis.
18
3 DESCRIPTION OF THE ACTION
3.1 Action Area
The USFWS defines the Action Area as "all areas to be affected directly or indirectly by the
federal action and not merely the immediate area involved in the action" (50 Code of Federal
Regulations [CFR] §402.02.). The Action Area for this project includes the Lower Feather River
from the limit of anadromous fish distribution at the Fish Barrier Dam to the confluence of the
Feather and Sacramento rivers at Verona. (Figure 1). Additionally,the FRFH located near the
Fish Barrier Dam is included in the Action Area.
3.2 List of Actions
Four potential actions taken in response to the Oroville Spillway Incident that may have
adversely affected protected species, Critical Habitat, and Essential Fish Habitat include 1) use
of the Emergency Spillway and damaged FCO Spillway, 2) material removal in the Thermalito
Diversion Pool, 3)four periods of rapid-flow ramping resulting from FCO Spillway operations,
and 4) activities undertaken at the Feather River Fish Hatchery.
On February 7, 2017, discharge at the FCO Spillway had been ramped up to 52,250 cubic feet
per second (cfs) in anticipation of high inflows to the reservoir from predicted precipitation, and
unusual flow patterns were observed on the FCO Spillway by CDWR employees. The FCO
Spillway discharge was stopped for inspection and a large area of erosion of the concrete
structure was observed. After determining the damage was too extensive to repair quickly,
CDWR began consulting with FERC and the California Division of Safety of Dams (DSOD).
The following day(February S, 2017), short duration test flows of 20,000 cfs were initiated and
erosion patterns were monitored. Although further erosion was observed from these test
flows, on February 9 the erosion began to stabilize and FCO Spillway flows were increased to
35,000 cfs and again to 45,000 cfs. Flow from the Hyatt Powerplant (HPP) was halted during
this time as the debris entering the Thermalito Diversion Pool (TDP) had raised water levels
enough that the HAP could not be operated safely. Concurrently, preparations were made for
use of the Emergency Spillway by clearing trees and debris from the hillside below the
Emergency Spillway.
Following peak inflow to the reservoir of> 190,000 cfs on February 9, the FCO Spillway
discharge was increased to 55,000 and then 65,000 on February 10.
On the morning of February 11, water began flowing over the Emergency Spillway for the first
time since its construction. The following day (February 12), erosion at the base of the
Emergency Spillway was observed to be progressing faster than expected. The FCO Spillway
discharge was increased to 100,000 cfs to lower the elevation of the reservoir more rapidly and
19
disengage the Emergency Spillway. Flow over the Emergency Spillway ceased on the evening of
February 12, 2017.
Beginning on February 13, helicopters and heavy construction equipment began to move
material into areas of erosion on the FCO Spillway and as reinforcement to the Emergency
Spillway. Significant amounts of debris entered the TDP as flows from the FCO Spillway were
sustained at 100,000 cfs. Equipment was staged to begin removing debris from the TDP at the
base of the damaged FCO Spillway. Flows from the FCO Spillway were reduced to 80,000 cfs on
February 16 to allow debris removal in the TDP but these efforts had limited effectiveness at
the high flow levels.
Erosion control and repair continued as flows decreased to 70,000 cfs on February 17 and
55,000 cfs on February 18. Flows were then increased to 60,000 cfs due to storm predictions
and were held at that level through February 23 as erosion control efforts continued. On
February 23, flows were reduced to 50,000 cfs. On February 27,flows from the FCO Spillway
were decreased from 50,000 to 0 cfs to minimize potential erosion of the FCO Spillway and
facilitate debris removal in the TDP. The FCO Spillway discharge remained at 0 cfs through
March 17 while debris removal efforts cleared the material that had been transported into the
TDP. Flow into the TDP resumed through the HPP at a rate of 2,650 cfs when it was restarted
on March 3. The HPP was temporarily shut down again on March 4 and restarted again on
March 5 at 1,720 cfs. As more turbines came online, additional flow was released from the
HPP. Flows through the plant increased to 3,550 cfs on March 6; 5,330 cfs on March 7; 8,800
cfs on March 9; and 12,900 cfs on March 10. Although the incident necessitated reducing
releases from the FCO to 0 cfs in the TDP, discharge in the Low Flow Channel (LFC) and High
Flow Channel (HFC) remained at or above minimum flows required for protection of fisheries
resources. Flows were released from the TDP into the LFC to maintain a minimum flow of 600
cfs and water was discharged from the Thermalito Afterbay Outlet (TAO) into the HFC so that
flow never dropped below the minimum requirement of 1700 cfs (Figure 8).
20
140000
-- _ Low Flow Channel
120000
—High Flow Channel
100000
80000
u
3
0
M 60000 y
40000
4 rl
.. r
I
20000
1
I t ti
0 I - L ..
oti1 oy'1 O,� +J,y'1 D,y'1 '1 O,^ O,� D,yA
SV 4V
Date
Figure S. Discharge in the Low Flow Channel and High Flow Channel of the Feather river between
January 1, 2017 and September 30, 2017.
Between February and June 2017, four periods of rapid flow reduction from the FCO Spillway
occurred. In addition to the February 27 flow reduction described above, three additional flow
reductions occurred on March 27, 2017; May 1, 2017; and May 19, 2017 (Figure 8).
Approximately 1.4 million cubic yards (cy) of debris was removed from the TDP from February
27 to June 1. By November 1, 2017, a total of 2.0 million cy of debris had been removed from
the TDP.
3.3 National Marine Fisheries Service Recommendations
A letter was sent from NMFS to FERC on February 24, 2017 expressing concern regarding the
potential effects to CCV Steelhead, sDPS Green Sturgeon, and Spring-run Chinook Salmon
caused by rapid reduction in flows from the FCO Spillway of 60,000 cfs to zero. These rapid
reductions were being proposed to minimize damage to the FCO Spillway and complete the
dredging of the Thermalito Diversion Pool. Adverse impacts due to a rapid reduction in flow
such as decrease in available habitat and stranding of fish in off-channel pools were listed
among the concerns. Dredging can affect the species listed above as well as fish at the FRFH
due to changes in water quality such as increasing turbidity and changing oxygen and pH levels.
21
Included in the letter was a list of recommendations to reduce the impacts on anadromous
species, Critical Habitat, and EFH in the Feather River downstream of the Fish Barrier Dam
during and after dredging operations which took place from February 27-October 20, 2017. A
summary of the recommendations and associated actions taken are listed below:
1. Reductions in flows should occur during hours of darkness on the Feather River to
protect juvenile salmonids, especially Chinook Salmon.
Action taken: During initial dredging activities, from February 27- March 17, decreases in
release rates from Oroville Dam occurred mainly during daylight hours to provide for
critical day-time monitoring of the FCO Spillway, which was being visually monitored for
damage on a continuous basis. Day-time monitoring was required for the safety of
CDWR personnel and contractors and to allow the most effective monitoring conditions.
2. Reductions in flows (down ramping rate) should occur as slowly as possible, to allow fish
to follow the receding water elevation.
Action taken: On February 27, 2017, release rates from Oroville Dam FCO Spillway were
rapidly decreased to accommodate the required (emergency) assessments and
continued to decrease until 0 cfs was released over the FCO Spillway. Also, there was
concern that damage to this structure,may be exacerbated during flow reductions below
about 40,000 cfs due to the possibility'of increased head cut erosion. Flows remained
low for about one week in the LFC and HFC, but never went below minimums for each
channel. Flow levels were increased slightly on March 7 and release rates began to rise
again until they peaked around 43,000 cfs on March 17 (Figure S). In addition to the
February 27 flow reduction described above, three additional flow reductions occurred
on March 27, May 1, and May 19, 2017.
3. Minimum flows should be maintained at all times. Flows should not drop below the
minimum instream flows. If flows are expected to drop below the minimum instream
flows, CDWR should release water from the spillway to ensure minimum instream flows
are met.
Action taken: Water was released from the Thermalito Diversion Dam into the LFC to
maintain a minimum flow of 600 cfs. Water was discharged from the TAO so that flow
entering the HFC never dropped below the minimum flow of 1,700 cfs.
4. Consider initially dredging a channel through the debris that will allow water to flow to
maintain minimum flows or more. Provide flow through the river valves and/or the
powerhouse. Repairs at the powerhouse and river valves should be prioritized to
provide water to the Feather River immediately.
Action taken: Water was released from the Thermalito Diversion Dam into the LFC to
maintain minimum flow of 600 cfs. Water was discharged from the TAO so that flow
22
entering the HFC never dropped below the minimum flow of 1,700 cfs during dredging
operations. Dredging operations were accelerated to remove material deposited in the
Thermalito Diversion Pool. Removing this material allowed Hyatt power plant to come
on-line quickly so water could continue to be released from Lake Oroville and continue
down the Feather River when lake levels dropped below the FCO Spillway.
5. Address water supply issues (quantity and quality) at the FRFH and the Thermalito
Annex. Ensure adequate water is available to these facilities and that the turbidity,
oxygen, and pH stay below levels that will stress fish.
Action taken: CDWR and CDFW closely monitored water parameters and supply issues.
To ensure adequate water quality for fish, approximately 2 million Spring-run Chinook
Salmon and about 4.2 million Fall-run Chinook Salmon were moved to the Annex facility.
A sedimentation channel and filtration system was set up for the fish and CCV Steelhead
eggs that remained at the FRFH. More details can be found in section 6.4.
6. Monitor/survey for stranding in the Feather River and implement fish rescues as
possible.
L Take pictures and video of locations and fish sampled. Check the date stamp
on the cameras. With the video frequently verbally record the time, date,
and location.
ii. In the case of survey, the numbers and species of fish should be estimated
and recorded.
iii. In the case of fish rescues, the numbers and species of fish should be
identified, and pictures taken. Where possible and it will not significantly
impact the implementation of fish rescue, tissue samples and scales should
be collected. The date, time, location, presence or absence of adipose fins,
and who collected the sample recorded on the bag. Number the bags and
locations. Freeze large fish as soon as possible.
Action taken:Aerial surveys were performed to determine the extent of stranding ponds
and focus field staff efforts on areas of concern. An aerial survey was completed on
February 26 prior to the decrease in release rate and another on February 27 when flow
in the LFC dropped to 600 cfs to determine the stranding pools in the LFC and HFC
created by the decrease in flow. Another two flights were completed on February 28;
one to inform on-ground surveys and another to gather high-resolution aerial
orthorectified photographs (orthophotographs) of the stranding areas on the entire
Lower Feather River, consisting of 67 RMs. The upper 53 RMs of the high-resolution
aerial orthophotographs were used to map and measure ponded areas using ArcView
GIS v.10.4.
23
On-the ground stranding pool surveys and rescues began on February 27 starting at
RM14 through RM66. Significant floodplain that developed below the confluence with
Sutter Bypass (below RM 14) made surveys in this area impossible. Larger ponds in the
remaining 14 mi were sampled using eDNA techniques to detect the presence of
salmonids and sturgeon. Primary, on-the-ground surveys ended on March 15 when .
flows had increased to 40,000 cfs and most of the pools had reconnected with the
Lower Feather River. Additional sampling occurred during subsequent ramp-down
events.
Tissues samples and otoliths (adult CCV Steelhead) were collected from many of the
observed salmonid mortalities. Information on location, date, and basic species
information was recorded. Samples were preserved by freezing or alcohol. Photographs
were taken of some locations to further document observations.
7. Monitor water quality, turbidity, DO, pH, and adjust dredging operations if these
parameters reach levels that may adversely affect fish at the Fish Barrier Dam or in the
hatchery.
Action taken: See Recommendation #5 for monitoring at FRFH.
When the Thermalito Diversion Pool was being dredged, average turbidity in the
Diversion Pool 300 ft downstream from the dredging peaked at 639 Nephelometric
Turbidity Units (NTU) on March 2, 2017. Turbidity and total suspended solids gradually
declined over several days following the spillway incident after peaking on March 2 and
then remained at values approximately between 30 and 70 NTUs and 10 and 30 mg/L,
respectively, for a month.
8. Water should be released from the Thermalito Afterbay to augment flows in the Feather
River, while maintaining water deliveries to the Thermalito Annex.
Action taken:Water was released from the TAO into the Lower Feather River to meet flow
requirements.
9. If possible, install turbidity curtains or booms to reduce potential turbidity levels,to the
maximum extent possible.
Action taken:This was not possible due to the large area being dredged with multiple
vessels, and high flows in the short timeframe that was available.
10. Coordinate with the Corps, Yuba County Water Agency, PG&E and the Nevada County
Irrigation District to augment flows from storage in the Yuba watershed. Also
coordinate with South Sutter Water District regarding the availability of water from the
Bear River for flow augmentation.
24
Action taken: Minimum flows were maintained in the LFC and the HFC during dredging,
therefore no flow augmentation was necessary. Flows to the lower Feather River were
quite high throughout the winter and spring except when flows were reduced for
spillway inspections (Figure 8).
11. Deploy as many people as possible to survey and respond to fish stranding, and
coordinate with CDFW.
Action taken: An exceptionally large workforce consisting of staff from CDWR, CDFW,
NMFS, and the Pacific State Marine Fisheries Commission (PSMFC) was deployed to
sample stranding pools and perform fish rescues during the first week of sampling
following flow reductions for dredging. During the second week, a reduced team from
the same agencies sampled larger pools that were previously inaccessible. CDWR
continued to sample and rescue fish (as possible) immediately after each subsequent
flow reduction (White et al. 2017).
12. Submit a report of the activities and results to NMFS within 30 days.
Action taken: Due to the extensive nature of the rescue and sampling effort and the long
duration of the work (well past 30 days), CDWR was not able to submit a full report of
the results of the stranding effort until November. However, CDWR did submit email
updates to NMFS as data was available during the stranding surveys and weekly
meetings were held to discuss all aspects of the spillway response including water
quality and stranding efforts.
3.4 Consultation History
The following timelihe describes key communications during the consultation process:
February8, 2017: Eric See (CDWR) called Gary Sprague (NMFS)to notify and discuss the
emergency situation.
February8, 2017: Julie Brown and Jason Kindopp (CDWR) participated in a conference call with
the Hatchery Operations Team to discuss hatchery actions needed during the emergency.
NMFS and CDFW were on the call as well.
February 8, 2017: Jason Kindopp (CDWR) coordinated fish survey and rescue schedule with
Colin Purdy(CDFW)and notified Gary Sprague and Howard Brown (NMFS). Due to changing
flow conditions (and the fact that flows were scheduled to be brought back up soon), this
discussion specifically regarding rescue efforts for the river was postponed until conditions
changed. Planning efforts resumed on 2/24.
25
February 10, 2017: Jason Kindopp (CDWR) emailed a general update to Gary Sprague and
Howard Brown (NMFS), including an update of the Oroville Spillway situation, and an update on
the status of the FRFH. The email included turbidity readings at Auditorium Riffle (near the
FRFH,just below the TAO, Gridley, and Yuba City. CDWR will continue to take turbidity
readings in the TDP and the LFC of the Feather River.
February 13, 2017: Gary Sprague (NMFS) inquired to Jason Kindopp (CDWR) of the status of
the fish at the FRFH. CDWR's response was that on February 11 everything was in place to keep
CCV Steelhead eggs in good condition and overall turbidity was increasing due to the use of the
Emergency Spillway. On February 12, river turbidity was significantly down so conditions in the
FRFH were improving.
February 24, 2017: Jason Kindopp (CDWR) requested a meeting with CDFW, NMFS, and SWRCB
staff to discuss plans for monitoring stranding when flows are expected to reduce from 50,000
cfs to 600 cfs in the Low Flow Channel on Monday, 2/27.
February 24, 2017: NMFS letter to FERC regarding "Technical Assistance and
Recommendations regarding the Oroville Dam Spillway Activities under the Endangered Species
Act, Magnuson-Stevens Fishery Conservation and Management Act, and Fish and Wildlife
Coordination Act for Oroville Facilities Hydroelectric Project, Butte County California (FERC
Project No. 2100)". NMFS provided 12 recommendations to minimize the effects on
anadromous fish species, Critical Habitat, and Essential Fish Habitat in the Feather River. NMFS
also stated that formal consultation should be initiated as soon as practicable after the
emergency is under control.
February 27, 2017: Conference call with NMFS, CDFW, Central Valley Regional Water Quality
Control Board (CVRWQCB), and CDWR to discuss CDWR's plans to monitor for stranding in the
Lower Feather River when flows reduce from 50,000 cfs to 600 cfs in the LFC (and
approximately 1,800 cfs in the HFC) on February 27. Key discussion items included background
and need for flow reduction, scheduled reduction (ramping rates and times), current CDWR
plan, input/suggestions, and participation from Agency staff.
February 27, 2017: Conference call with NMFS, FERC, and CDWR to discuss recommendations
in the February 24, 2017 from NMFS to FERC.
February 28, 2017: NMFS issued follow-up correspondence acknowledging the emergency
nature of the actions and that public safety and the protection of life and property are of
utmost importance during operations and emergency repairs at Oroville Dam.
February 23-25, 2017: Conference calls with NMFS, CDFW, and CDWR. A plan for fish
survey/rescue was developed.
February 2017: Continued coordination with Howard Brown and Gary Sprague (NMFS); Colin
Purdy, Anna Kastner, and Tracy McReynolds (CDFW); and CDWR regarding Feather River fish
26
issues including fish stranding, hatchery, water quality, water filtration, and relocation of fish in
the hatchery.
March 23, 2017: Conference call between Eric See (CDWR) and Howard Brown (NMFS). At this
time, NMFS is unsure what is expected of them, as much of the proposed work occurs outside
of NMFS'jurisdictional area. CDWR is unsure that additional coordination can be done with
NMFS right now.
March 24, 2017: CDWR letter to FERC requesting to be designated non-federal representative
status for consultation for the Endangered Species Act (ESA) Sec. 7 and National Historic
Preservation Act (NHPA) Sec. 1.06
March 31, 2017: FERC letter to the California State Historic Preservation Officer (SHPO), U.S.
Fish and Wildlife Service (USFWS), and NMFS designating CDWR as non-federal representative
for ESA and NHPA.
March 2017—June 2017: Twice weekly calls regarding environmental coordination and
updates: Participants include NMFS,USFWS, FERC, Federal Emergency Management Agency
(FEMA), U. S. Army Corps of Engineers (USACE), CDFW, California Office of Emergency Services
(CaIOES), CVRWQCB, State Water Resources Control Board (SWRCB), and CDWR.
April 20, 2017: FERC letter to FEMA and USACE confirming FERC will be acting as lead agency.
April 20,2017: FEMA letter to FERC confirming that FERC is assuming the Lead Agency role.
May 18, 2017: FERC letter to FEMA and USACE formally designating CDWR as non-federal
representative for consultation under the ESA and NHPA for Recovery.
July 2017—September 2017: Once weekly environmental coordination and updates calls
regarding environmental coordination and updates: Participants include NMFS, USFWS, FERC,
FEMA, USAGE, CDFW, CalOES, CVRWQCB, SWRCB, and CDWR.
September 2017 to present: Calls changed to every two weeks.
July 19, 2017: Meeting at NMFS office regarding Feather River fish habitat restoration. In
attendance were representatives of NMFS, USFWS, FERC, USACE, CDFW, and CDWR.
September 7, 2017: Meeting at NMFS office to discuss consultation for Oroville Spillway
Emergency and steps forward. In attendance were representatives of NMFS, FERC, and CDWR.
October 5, 2017: Meeting at NMFS office to discuss consultation for Oroville Spillway
Emergency and steps forward. In attendance were representatives of NMFS, FERC, and CDWR.
November 16, 2017; December 14, 2017; January 11, 2018; February 15, 2018, March 13,
2018,April 19, 2018, and May 14, 2018: Additional meetings to discuss emergency
27
consultation for the Oroville Spillway Emergency. In attendance were representatives of NMFS,
FERC, and CDWR. USFWS representative in attendance on February 15, 2018.
28
4 SPECIAL STATUS SPECIES
For the purposes of this BA, adverse impacts from the response to the Oroville Spillway Incident
were assessed for three special status species (two runs of Chinook Salmon) and their habitats
known to occur in the action area; sDPS Green Sturgeon, CV Spring-run Chinook Salmon,
Winter-run Chinook Salmon, and CCV Steelhead (Table 2). Each of these species meets the
following criteria. A. Species under NMFS purview that are listed as threatened or endangered
under the ESA (50 CFR 17.11 for listed animals).
Additionally, EFH for Chinook Salmon may have also been affected by the response to the
Oroville Spillway Incident and is also shown in Table 2 below.
Table 2. Special status anadromous species that may occur within the Action Area.
Critical Habitat or
Common Federal Potential for
Scientific Name Essential Fish Habitat Association
Name Status Occurrence
.Habitat
Acipenser North Threatened Designated Critical Mainstream Sacramento River Certain;the Action Area
medirosfris American Habitat in the downstream of Keswick Dam overlaps the range and
Green Action Area(74 FR (including the Yolo and Sutter habitat of species
Sturgeon 52300-52351, bypasses),the Lower Feather
October 9,2009). River below Fish Barrier Dam,
the Yuba River below Daguerre
Point Dam,and the
Sacramento-San Joaquin Delta.
NMFS 2009a
Oncorhynchus California Threatened Designated Critical Drainages of Sacramento and Certain;the Action Area
mykiss Central Habitat in the San Joaquin rivers San overlaps the range and
Valley Action Area(70 FR Francisco,San Pablo,and habitat of species
Steelhead 52488-52536, Suisun bays eastward to
September 2, Chipps Island.
2005
Oncorhynchus Spring-run Threatened Designated Critical Drainages of Sacramento and Certain;the Action Area
tshawyfscha Chinook Habitat in the San Joaquin rivers San overlaps the range and
Salmon Action Area(70 Francisco,San Pablo,and habitat of species
CFR 52488- Suisun bays eastward to
52536,September Chipps Island.
2,2005).
Oncorhynchus Chinook FMP,MSA Essential f=ish Drainages of Sacramento and Certain,the Action Area
tshawytscha Salmon managed Habitat San Joaquin rivers.San overlaps the range and
species Francisco,San Pablo,and habitat of species
Suisun bays eastward to
Chip s Island.
Oncorhynchus Winter-run Endangered No designated Drainages of Sacramento river. Likely;a recent study has
tshawyfscha Chinook Critical Habitat in San Francisco,San Pablo,and indicated some non-natal
Salmon the Action Area(58 Suisun bays eastward to rearing occurs in the
FR 33212-33219, Chipps Island Action Area.
June 16,1993).
29
Critical periods of federally listed species present•within the Action Area are shown in Table 3
below.
Table 3. Critical periods for federally listed species present with the Action Area. The dark gray squares
represent the primary period of occurrence for that life stage and light gray the secondary period. No
color represents absence or very low presence of the life stage.
Feather River Month.Present
Species/Life Stage I Distribution Jan Feb Mar 1.Apr May Jun Jul Aug Sep Oct I Nov I Dec
Central Valley Spring-run Chinook Salmon
Adult migration Low Flow Channel,
and holding High Flow Channel
Adult spawning Low Flow Channel
Egg incubation Low Flow Channel = '
Juvenile Low Flow Channel,
%E q 3 i5 y z5 # ami y3s
emergence and High Flow Channel 12
rearing
Juvenile/smolt Low Flow Channel,
� uFL
emigration High Flow Channel
Sacramento River Winter-runt.Chinook Salmon
Adult holding and None
spawning
Egg incubation None
Non-natal juvenile High Flow Channel i r
rearing ;tE
California Central Valley Steelhead
Adult migration Low Flow Channel,
High Flow Channel
Adult spawning Primarily Low Flaw
rK.
Channel V e
Egg incubation Primarily Low Flow ` f` 2
Channel
Juvenile Primarily Low Flow
emergence and Channel a
-
rearing .-,,:f
Juvenile/smolt Low Flow Channel, acv
emigration High Flow Channel �' '�
30
Feather River
Species/Life Stage Distribution Month Present
Jan Feb Mar /Apr May. Jun Jul Aug Sep Oct Nov Dec
.Green Sturgeon
Adult migration Low Flow Channel, rr
High Flow Channel I
Adult spawning High Flow Channel ,_s ff
except in wet years
Egg incubation Low Flow Channel,
High Flow Channel ``
Larval emergence Low Flow Channel,
High Flow Channel
Larval and juvenile Low Flow Channel, `
s
rearing High Flow Channel
Juvenile Low Flow Channel,
f
emigration High Flow Channel1 Mal
¢ r s L
4.1 California Central Valley Steelhead (Oncorhynchus mykiss)
Distinct Population Segment
4.1.1 Listing Status
The CCV Steelhead DPS is listed as threatened by federal ESA(71 FR 834, 79 FR 20802) and the
lower Feather River below Oroville Dam is included in the designated Critical Habitat (70 FR
52488). Critical Habitat is defined by ESA as specific areas within a geographic region where the
habitat values are essential for conserving the species. This designation includes river and
adjacent riparian areas (NMFS 2005), and restoring rearing areas may be important for
conservation (NMFS 2014).
4.1.2 Distribution
The CCV Steelhead DPS includes all naturally spawned Steelhead populations in the Sacramento
and San Joaquin rivers and tributaries. Propagated stocks from Coleman National Fish Hatchery
on Battle Creek and the FRFH are also included in the CV DPS (NMFS 2014). CCV Steelhead are
distributed in CV rivers and streams from the Sacramento River in the north to the Merced
River in the south (NMFS 2014).
4.1.3 Habitat Requirements and Life Ecology
CV Steelhead have the greatest diversity of life history patterns of any Pacific salmonid species,
including varying degrees of anadromy, differences in reproductive biology, and plasticity of life
history between generations (Sogard et al. 2012). Adult migration from the ocean to CV
spawning grounds occurs during much of the year, with peak migration occurring in the fall or
31
early winter (Table 3). Migration through the Sacramento River main stem begins in July, peaks
at the end of September, and continues through February or March (Bailey 1954; Hallock et al.
1961; both as cited in McEwan et al. 1996, Table 3). CCV Steelhead are mostly `winter
Steelhead';that is,they mature in the ocean and arrive on the spawning grounds nearly ready
to spawn. In contrast, 'summer Steelhead', or stream-maturing Steelhead, enter freshwater
with immature gonads and typically spend several months in freshwater maturing before
spawning. Winter Steelhead prefer cold water between 13°C—21°C that is saturated with
dissolved oxygen (DO). In the Feather River,two forms of O. mykrss exist: rainbow trout, the
resident form that remains in the river its entire life; and Steelhead, the anadromous form that
migrates to the ocean as a juvenile and returns to the river to spawn one or more times
(Mitchell 2010). The relationship between resident and anadromous forms is not well
understood, but some evidence suggests the two forms interbreed and produce juveniles of the
alternate form (Shapovalov and Taft 1954; Zimmerman et al. 2009; Courter et al. 2013; Kendall
et al. 2014). No genetic differentiation has been found between forms, supporting this
hypothesis (Busby et al. 1993; Nielsen 1994; Docker and Heath 2003; Van Doornik and
Berejikian 2015). Additionally, the FRFH propagates CCV Steelhead as mitigation for production
lost after construction of Oroville Dam.
Historically, CCV Steelhead spawned primarily in upper stream reaches and smaller tributaries.
As a result of CV water development projects, most spawning is now confined to lower stream
reaches below dams. In a few streams, such as Mill and Deer creeks, CCV Steelhead still have
access to historic spawning areas. CCV Steelhead migrate up the Sacramento River nearly every
month of the year, with the bulk of migration occurring from August through November, with
the peak in late September (Bailey 1954; Hallock et al. 1961; McEwan 2001). While little
information has been collected on migration patterns for the San Joaquin River tributaries,
migration has been observed as early as August and as late as May with peaks in January and
February on the lower Mokelumne River (Workman 2005). Spawning in the upper Sacramento
Diver generally occurs between November and late April, with a peak between early January
and late March (NMFS 2014). Similar observations have been made on the Mokelumne River
(Mulchaey and Setka 2007). CCV Steelhead typically return from the ocean at ages two or
three, weighing 2—12 lbs (0.9—5.4 kg) (Reynolds et al. 1993). Adult CCV Steelhead migration
and holding in the lower Feather River occurs from August through March, with spawning
occurring from January through March (Hartwigsen and Reid 2009, Table 3). CCV Steelhead are
generally iteroparous; they may return to the ocean after spawning and repeat the spawning
cycle (Varum et al. 2008). The percentage of Feather River CCV Steelhead adults repeat
spawning has been documented between — 1- and 5% (Mercer and Kurth 2012).
CCV Steelhead in the Lower Feather River primarily use riffle habitats with substrates composed
of small and large gravel (Hartwigsen and Reid 2009). The survival of embryos is reduced when
fine substrates with a diameter smaller than 0.5 inches (1.3 cm) comprises more than 20-25
percent of the total substrate by volume. Studies have shown higher embryo survival when
intragravel velocities exceed eight in/hr (0.2 m/hr) (Coble 1961; Phillips and Campbell 1961).
The number of days required for CCV Steelhead eggs to hatch is inversely proportional to water
32
temperature and varies from about 19 days at 15.6'C (60.1 °F) to about 80 days at 5.6°C (42.1
°F). Embryo incubation occurs mostly in the upstream end of the LFC from January through
May (Cavallo et. al 2003). Fry typically emerge from the gravel two to three weeks after
hatching (Barnhart 1986). Upon emerging from the gravel, fry rear in stream margin habitats
and move gradually into pools and riffles as they grow larger (Merz et at. 2015). Older fry
establish territories, which they defend. Cover is an important habitat component for juvenile
CCV Steelhead both.as velocity refuge and as a means of avoiding predation (Shirvell 1990;
Meehan and Bjornn 1991). CCV Steelhead, however, tend to use riffles and other habitats not
strongly associated with cover during summer rearing more than other salmonids. Suitable
habitat in the Lower Feather River can be found in main channel of the LFC and the HFC, but the
bulk of rearing occurs in Hatchery Side Channel and other smaller side channels where there is
abundant instream and overhead cover(Mercer 2012). Young CCV Steelhead feed on a wide
variety of aquatic and terrestrial insects, and gradually become more piscivorous as they grow,
emerging fry are sometimes preyed upon by older juveniles (Merz and Vanicek 1996; Merz
2002). In winter, they may become less active and hide in any available cover, including gravel
or woody debris.
Rearing juvenile CCV Steelhead may reside in freshwater all year(Merz 2002; Sogard et al.
2012; Merz et al. 2015; Table 3). Water temperature and food availability influence the growth
rate, population density, swimming ability, ability to capture and metabolize food, and ability to
withstand disease (Barnhart 1986; Bjornn and Reiser 1991; Sogard et al. 2012). Optimal
temperatures for Feather River CCV Steelhead growth range between 62.6 and 68.0 OF (17 and
20°C), and juvenile CCV Steelhead have an upper lethal limit of 85.8°F (29.9°C) (Myrick and Cech
2000).
Adequate flow and water temperature conditions are important factors for juvenile survival
and growth (CDFG 1997). During rearing, suspended and deposited fine sediments can directly
affect salmonids by abrading and clogging gills, and indirectly cause reduced feeding, avoidance
reactions, destruction of food supplies, reduced egg and alevin survival, and changed rearing
habitat (Suttle et al. 2004; Reiser and Bjornn 1979). Bell (1973)found that silt loads of less than
25 milligrams per liter(mg/1) permit good rearing conditions for juvenile salmonids. Increasing
concentrations of deposited fine sediment in gravel bedded streams has been observed to
decrease growth and survival of juvenile salmonids (Suttle et al. 2004; Harvey et al. 2009).
Generally, CCV Steelhead that are successful in surviving to adulthood spend at least two years
in freshwater before emigrating downstream (Sogard et al. 2012). However, CV populations
below non-passable barriers contain some component of the population that does not
demonstrate anadromy(Sogard et al. 2012). Emigration appears to be more closely associated
with size than age but environmental conditions appear to influence the proportion of the
population demonstrating anadromy (Sogard et al. 2012). While juvenile CCV Steelhead rearing
and downstream migration occurs year-round, the peak emigration period for naturally-
spawned CCV Steelhead juveniles migrating past Knights Landing on the lower Sacramento
River has ranged from late December through May (McEwan 2001). Feather River rotary screw
33
trap (RST) data from multiple locations collected CCV Steelhead from February through June,
with peaks in March and April at both locations (Bilski and Kindopp 2009). In streams south of
the American River, CCV Steelhead emigration has been observed from November through July
(Bilski and Rible 2011; Cramer Fish Sciences 2015).
4.1.4 Current Status and Distribution
Analyses of CCV Steelhead abundance.across the DPS indicate that naturally reproducing stocks
are suffering severe and long-term declines, range-wide, within the Sacramento River, and
within the Action Area (NMFS 2014). There are small, remnant populations of CCV Steelhead
present in the upper Sacramento River and its tributaries below impassable barriers (NMFS
2014). Recent counts of CCV Steelhead in several of these streams indicate that they generally
have CCV Steelhead returns of less than 1.,000 adults (NMFS 2016). In the San Joaquin River
tributaries, the CCV Steelhead populations are very small with most fish apparently
demonstrating the resident phenotype (Zimmerman et al. 2009; Sogard et al. 2012). Trawl data
at Chipps Island suggests that natural production of CCV Steelhead is very low (NMFS 2016).
There is very little monitoring focused on CCV Steelhead; as a result, population trend and
status is largely unknown. These apparent population declines have been attributed to
longstanding human induced factors that exacerbate the adverse effects of natural
environmental variability (NMFS 1996). Important factors in this decline include destruction
and degradation of habitat, overutilization, and natural and human made factors (62 FR 43937).
Within the CCV Steelhead DPS region, significant destruction and degradation of freshwater
spawning and rearing habitat has occurred. Impassable dams block access to 80 percent of
historically available habitat and block access to all historical spawning habitat for about 38
percent of historical populations (Lindley et al. 2006). RST data on the Lower Feather River
show fry begin to emigrate downstream shortly after emergence and numbers decrease as the
season progresses with few CCV Steelhead older than age-0 collected (Bilski and Kindopp 2009).
Snorkel surveys documented juvenile CCV Steelhead presence through August with most fish
observed in the upper mile of the LFC (Mercer 201.2).
CCV Steelhead are currently propagated at the FRFH with an informal goal of collecting 1.5
million eggs each year (CHRP 2012). CCV Steelhead begin ascending the hatchery ladder in
September and FRFH staff attempt to distinguish anadromous and resident individuals based on
physical characteristics. Sexually immature fish, and fish smaller than 16 inches are returned to
the river. FRFH spawning typically starts in late December and ends in late February. Between
2000 and 2009, the FRFH trapped an annual average of 1,310 adult CCV Steelhead. In 2017,the
FRFH trapped over 1000 adult CCV Steelhead.
Eggs are incubated in the FRFH and juveniles are reared to a size of 4 fish/Ib. Yearling fish are
currently released at three locations: Boyd's Pump Launch Ramp, Live Oak Boat Ramp, and
Verona Marina. Releases generally occur in January or February and the yearling fish are never
held past March 15. Between 1998 and 2007,the hatchery released an average of 402,902
yearling CCV Steelhead/year(CHRP 2012).
34
4..1.5 Current Status of Critical Habitat
The condition of CCV Steelhead Critical Habitat throughout their range, and specifically its
ability to provide for their conservation, has been degraded from conditions known to support
viable salmonid populations. The depressed population conditions are in part due to
anthropogenic activities that have affected Critical Habitat. These activities include agricultural
and mining activities, dams, stream channel modification, wetland loss, and water withdrawals,
including unscreened irrigation diversions. Impacts of concern include alteration of stream
bank and channel morphology, alteration of water temperatures, loss of spawning and rearing
habitat, fragmentation of habitat, loss of downstream recruitment of spawning gravels and
LWD, degradation of water quality, removal of riparian vegetation resulting in increased stream
bank erosion, increases in erosion entry to streams from upland areas, loss of shade, and loss of
nutrient inputs. Depletion and storage of natural river flows have drastically altered natural
hydrologic cycles in most rivers in the DPS. Alteration of flows results in migration delays, loss
of suitable habitat due to dewatering and blockage; stranding of fish from rapid flow
fluctuations; entrainment of juveniles into poorly screened or unscreened diversions; and water
temperature alteration that adversely affects the species.
4.2 Central Valley Spring-run Chinook Salmon (Oncorhynchus
tshawytscha)
4.2.1 Listing Status
The CV Spring-run Chinook Salmon ESU is listed as threatened underthe ESA(64 FR 50394, 79
FR 20802) and the California Endangered Species Act (CESA) and Critical Habitat was designated
in 2005 (70 FR 52488), which includes the Lower Feather River below the Fish Barrier Dam.
4.2.2 Distribution
Historically, Spring-run Chinook Salmon occurred in the headwaters of all major river systems in
the CV that lacked barriers to migration (Yoshiyama et al. 2001). In the Feather River Spring-run
Chinook Salmon were found up to elevations of—5,000 ft (Yoshiyama et al. 2001). Fry 1961 (as
cited in Yoshiyama et al. 2001) reported runs of 1,000-4,000 Spring-run Chinook Salmon in the
Feather River, mostly spawning in the Middle Fork with smaller numbers spawning in the North
Fork, South Fork, and the West Branch. Since the construction of Oroville Dam (1967), the
majority of spawning habitat is inaccessible; however, spawning still occurs below the dam.
Returns to FRFH in the spring have averaged 7000 fish (adults and grilse) since CDWR and
CDFW began marking early returning adults in 2005 (CDWR, unpublished data).
4.2.3 Habitat Requirements and Ecology
In general, Spring-run Chinook Salmon enter the Lower Feather River in March through June as
immature adults and hold until mature in the late summer-fall. Spawning takes place from
35
September through October (NMFS 2009b; White et al. 2017; Table 3). The majority of Spring-
run Chinook Salmon spawning occurs from 1/2 mile below the Fish Barrier Dam to the Hwy 70
Bridge. Carcass surveys between 2010 and 2012 revealed that between 78 and 90%of fish
spawning in the Feather River were hatchery-origin fish (Kormos et al. 2012; Falmer-Zwahlen
and Kormos 2015). In the American River, egg survival of Fall-run Chinook Salmon varied with
temperature,the highest survival occurring when temperatures ranged between 53-54 "F; and
in the Sacramento River, eggs became more likely to die or suffered reduced viability above 57
'F and 100% mortality occurred when temperatures rose above 65 °F (Boles 1988; Hinze 1959,
as cited in Boles 1988). In the Feather River, temperature is strictly controlled at the FRFH and
in the LFC in September to target 52 °F but not exceed 56 `F. This creates appropriate
temperature in the river for spawning in September and October. In the Lower Feather River,
Spring-run Chinook fry begin emerging in early November and continue through January. Most
juveniles appear to emigrate from the upper river quickly and a smaller proportion hold and
rear through spring (Bilski and Kindopp 2009; Mercer 2012). Rearing habitat and conditions
require cover, space, and food, and in the lower reaches fry have been observed using channel
irregularities, instream and overhead cover, and low velocity channels to provide refuge
(Cavallo et al. 2003, Mercer 2012) as well as an increasing reliance on turbidity as cover
(Gregory and Levings 1998). Although emigration patterns can vary, RST data from the Lower
Feather River has shown two pulses of outmigration is typical, with a peak in December and
another small pulse of young-of-the-year outmigrating in April (Seesholtz et al. 2004; Bilski and
Kindopp 2009).
4.2.4 Current Status of Population
Historically, Spring-run Chinook Salmon were likely the most abundant salmonid in the CV, but
have suffered the most severe declines of any of the four CV Chinook Salmon runs (NMFS 2014;
Yoshiyama et al. 1998). CV Spring-run Chinook Salmon runs may have been as large as
1,000,000, but recent returns have averaged around 10,000 (NMFS 2014; Yoshiyama et al.
1998). Analyses of Spring-run Chinook Salmon abundance across the ESU indicate that
naturally reproducing stocks are suffering severe and long-term declines, range-wide, including
within the Action Area (NMFS 2014). Currently,there are only three CV streams (Mill, Deer,
and Butte creeks) that support self-sustaining and non-hybridized populations, and each of
these populations are small and isolated. The only hatchery that produces Spring-run Chinook
Salmon, FRFH, has experienced considerable hybridization between Spring-run and Fall-run
Chinook Salmon, imperiling the genetic integrity of the run (NMFS 2014).
The Fish Barrier Dam is the current limit of anadromy and natural production for Spring-run
Chinook Salmon in the Feather River. Spring-run Chinook Salmon are currently propagated at
the FRFH. Adults are allowed to enter the FRFH ladder from April 1 through June 30. Fish are
externally tagged and then released back into the river. Fish entering the hatchery during this
time are all considered Spring-run. The ladder is opened again around September 15 to begin
spawning operations. Approximately 650 male and 650 female adult Spring-run Chinook
Salmon are needed to meet the production goal of 2 million smolts. Eggs are incubated in the
36
hatchery and juveniles are normally reared to a size of 60 fish/Ib prior to release. This size is
usually achieved by April, depending upon temperature and spawn date. Fish are generally
released at two locations in the Lower Feather River(Gridley Boat Ramp and Boyd's Pump
Launch Ramp). Historically, smolts were also released near San Pablo Bay and the Lower
Feather Riverto assess stray rates and return rates of different release strategies. Since 2014,
all Spring-run Chinook Salmon have been released into the Lower Feather River to reduce
straying.
4.2.5 Current Status of Critical Habitat
CV Spring-run Chinook Salmon Critical Habitat has been degraded by a host of anthropogenic
impacts, and reaches with conditions known to support viable salmonid populations are
severely limited. This hinders the ability of current designated Critical Habitat to provide for
the conservation of Spring-run Chinook Salmon. Factors that have adversely affected Critical
Habitat include agricultural and mining activities, dams, stream channel modification, wetland
loss, and water withdrawals, including unscreened irrigation diversions. Impacts of concern
include alteration of stream bank and channel morphology, alteration of water temperatures,
loss of spawning and rearing habitat, fragmentation of habitat, loss of downstream recruitment
of spawning gravels and LWD, degradation of water quality, removal of riparian vegetation
resulting in increased stream bank erosion, increases in erosion entry to streams from upland
areas, loss of shade, and loss of nutrient inputs. Impassable dams prevent CV Spring-run
Chinook Salmon from accessing virtually all historic spawning habitat in the CV (Lindley et al.
2007). Depletion and storage of natural river flows have drastically altered natural hydrologic
cycles in most rivers designated as Critical Habitat. Alteration of flows can result in migration
delays, loss of suitable habitat due to dewatering and blockage, stranding of fish from rapid
flow fluctuations, entrainment of juveniles into poorly screened or unscreened diversions, and
stressful water quality conditions.
4.3 Sacramento Valley Winter-run Chinook Salmon
(Oncorhynchus tshawytscha)
4.3.1 Listing Status
The Sacramento River Winter-run Chinook Salmon was listed as threatened in 1989 under the
Federal ESA(54 FR 32085) and upgraded to endangered on January 4, 1994 (58 FR 33212-
33219). The Lower Feather River is not currently included in the designated Critical Habitat
locations (FR Notice (Vol. 58, No. 114, Page 33212, June 16, 1993; 50 CFR Part 226)); however,
1-2 Sacramento River Winter-run Chinook Salmon have potentially been collected in RSTs
within the Action Area in select years that fit the length criteria for Winter-run Chinook Salmon,
but no genetic analysis has been done to confirm race.
4.3.2 Distribution
37
Historically, Sacramento River Winter-run Chinook Salmon spawned in the upper reaches of the
Sacramento River as well as the McCloud and Pit rivers (Moyle et al. 1995). Currently, they are
restricted in their distribution by impassible dams with 58% of their original (pre-dam
construction) habitat accessible. All spawning occurs immediately downstream of Keswick Dam
on the Sacramento River(Moyle et al. 1995; USBR 2008). In the Feather River, Sacramento
River Winter-run Chinook Salmon likely rear in the lower reaches of the Feather River close to
the confluence with the Sacramento River. No observations have been made in the Feather
River in documented literature with the exception of 1-2 fish caught in the RST on the Lower
Feather River, however those fish were classified as Winter-run Chinook Salmon according to
length-date criteria, but were not confirmed as such with genetic analysis. However, a recent
study concluded that juvenile Winter-run Chinook Salmon use the Lower Feather River as non-
natal rearing habitat (Phillis et al. 2017).
4.3.3 Habitat Requirements and Life Ecology
After spending 1-3 years in the ocean, Sacramento River Winter-run Chinook Salmon begin
migrating inland through the Delta and Sacramento River beginning December, peaking in
March and ending in July, spawning from April through August (Moyle 2002). Winter-run
Chinook Salmon enter the river reproductively immature, holding in the colder water below
Keswick Dam (Moyle et. al 1989). Fry begin to emerge and move downstream with peak
emigration occurring in September and October(Vogel and Marine 1991). Some factors that
may trigger migration include high flows and high turbidity which are often the result of storm
events (USER 2008).
4.3.4 Current Status of Population
The historical abundance pre-Shasta dam construction is unknown and thoughts on population
size are variable ranging from several thousand to 200,000 fish (NMFS 1993; Slater 1963). CV
Winter-run Chinook Salmon runs may have been as large as 1,000,000, but recent returns have
averaged around 10,000 (NMFS 2014; Yoshiyama et al. 1998). In the 1960's, the population
was beyond 20,000 fish, but has since experienced continued declines, dropping dramatically in
the late 1980's and early 1990's when the run was listed as endangered under the CESA and
federal ESA. From 1990-1997, the population averaged 600 adults but experienced increases
from 1998-2016 when escapement gradually rose, averaging 4,770 fish. This escapement
includes fish collected at Livingston Stone National Fish Hatchery (LSNFH) (Moyle 2002;
GrandTab 2017).
Winter-run Chinook Salmon have been propagated at LSNFH since the mid- 1990's and are
considered to be part of the Sacramento River Winter-run Chinook Salmon ESU and have a goal
of managing the hatchery population to be less than 20% of the in-river escapement which they
have maintained successfully (NOAA 2011). As of 2010, only wild fish (non-clipped) are being
spawned at the hatchery in order to decrease the effects of domestication, however in 2015 a
38
Captive Broodstock Program was initiated using broodstock from the Conservation Hatchery
Program in response to drought conditions that threaten the status of the run (NOAA 2016).
4.3.5 Current Status of Critical Habitat
Sacramento Winter-run Chinook Salmon Critical Habitat has been degraded and conditions
known to,support viable salmonid populations are severely limited thus hampering the ability
of current designated Critical Habitat to provide for the conservation of Winter-run Chinook
Salmon. Factors that have adversely affected Critical Habitat include agricultural and mining
activities, dams, stream channel modification, wetland loss, and water withdrawals, including
unscreened irrigation diversions. Impacts of concern include alteration of stream bank and
channel morphology, alteration of water temperatures, loss of spawning and rearing habitat,
fragmentation of habitat, loss of downstream recruitment of spawning gravels and LWD,
degradation of water quality, removal of riparian vegetation resulting in,increased stream bank
erosion, increases in erosion entry to streams from upland areas, loss of shade, and loss of
nutrient inputs. Depletion and storage of natural riverflows have drastically altered natural
hydrologic cycles in most rivers in the DPS. Alteration of flows results in migration delays, loss
of suitable habitat due to dewatering and blockage, stranding of fish from rapid flow
fluctuations, entrainment of juveniles into poorly screened or unscreened diversions, and water
temperature alteration that adversely affects the species.
4.4 North American Green Sturgeon (Acipenser medirostris)
southern Distinct Population Segment
4.4.1 Listing Status
The North American Green Sturgeon sDPS is listed as threatened under the FSA (71 FR 17757).
Designated Critical Habitat for North American Green Sturgeon sDPS includes the Lower
Feather River below the Fish Barrier Dam (74 FR 52300).
4.4.2 Distribution
The North American Green Sturgeon sDPS includes the population spawning in the Sacramento
River watershed and using the Delta and San Francisco Bay. Adults range from Graves Harbor,
Alaska to Monterey Bay, California, most frequently occurring off the coast of Washington,
Oregon, Vancouver Island, and both San Francisco and Monterey bays (Moser and Lindley 2007;
Lindley et al. 2008, 2011; Huff et al. 2012). Adult and subadult Green Sturgeon sDPS can be
found in the warmer months moving into coastal bays and estuaries where they are likely
foraging or seeking thermal refugia (Moser and Lindley 2007). Telemetry studies have shown
that spawning adults quickly move through San Francisco Bay and into freshwater and that
subadults and non-spawning adults reside longer in the Bay, most likely to feed (Heublein et al.
2009; Lindley et al. 2011).
39
4.4.3 Habitat Requirements and Life Ecology
The Green Sturgeon is a large (up to 350 lbs), long-lived fish (up to 70 years) that reaches
maturity at around 15 years of age (NMFS 2015a). Green Sturgeon typically spawn every three
to four years (Poytress et al. 2015). Green Sturgeon adults on their spawning run enter San
:=rancisco Bay during late winter to early spring, migrate to their spawning area and spawn from
;April through early July (Heublein et al. 2009; Table 3). After spawning, Green Sturgeon sDPS
most commonly hold for several months in the river and then migrate downstream in the fall or
winter, although some adults migrate downstream during the spring and summer(Heublein et
al. 2009), Spawning takes place in deep pools with medium sized gravel, cobble, or boulder
substrate and at water temperatures from 10°C- 17°C (Poytress et al. 2015). Spawning in the
Sacramento River has been documented to occur at several sites (Poytress et al. 2015) and
spawning was recently documented in the Lower Feather River in the HFC near Thermalito
Afterbay and in the LFC near the Fish Barrier Dam (Seesholtz et al. 2015; A. Seesholtz (CDWR),
personal communication). Juvenile Green Sturgeon sDPS begin to migrate downstream
between 6 months and 2 years of age (NMFS 2015b). Subadult and adult Green Sturgeon sDPS
spend most of their life in the marine environment and are commonly found in coastal bays and
estuaries during the summer and fall (NMFS 2015a).
4.4.4 Current Status of Population
The number of adult sDPS Green Sturgeon estimated from surveys of the-spawning aggregating
sites in the upper Sacramento River from 20102014 ranged from 164±47 to 526 ±64 (Mora et.
al 2015 as cited by NMFS 2015b). Extrapolating from this survey and mean spawning
periodicity, Klimley et al. (2015) estimate the Green Sturgeon sDPS population to be 1,348
524 adults. However, this survey did not account for sDPS Green Sturgeon in the Lower Feather
River, where spawning was recently documented (Seesholtz et al. 2015).
In the Lower Feather River, Green Sturgeon sDPS have been documented at multiple locations
in the HFC, and spawning was documented below the TAO in 2011 (Seesholtz et al. 2015).
During 2017, Green Sturgeon were detected, and spawning surveys collected eggs and larvae
near the Fish Barrier Dam in the LFC (CDWR unpublished data).
4.4.5 Current .Status of Critical Habitat
The condition of sDPS Green Sturgeon Critical Habitat, specifically its ability to provide for their
conservation, has been degraded from conditions known to support viable sturgeon
populations. Impassable dams prevent sDPS Green Sturgeon from accessing historical
spawning habitat in the Sacramento, Feather, and Yuba rivers. The depressed population
conditions are in part due to anthropogenic activities that have affected Critical Habitat
including: agricultural and mining activities, dams, stream channel modification, wetland loss,
and water withdrawals, including unscreened irrigation diversions. Impacts of concern include
alteration of stream bank and channel morphology, alteration of water temperatures, loss of
40
spawning and rearing habitat, fragmentation of habitat, degradation of water quality, and flood
bypass systems that impede migration and cause stranding.
41
5 CRITICAL HABITAT AND ESSENTIAL FISH HABITAT
5.1 Critical Habitat and EFH within the Action Area
Critical Habitat is defined as specific locations within the geographical area occupied by federal
ESA listed species in which are found those physical and biological features essential to the
conservation of the species and which may require special management considerations or
protections (ESA section 3(5)(A)(1)). EFH applies to Pacific salmon and other commercial fish
species and is defined as the aquatic habitat necessary for spawning, breeding, feeding, or
growth to maturity. See Section 1.3 for additional details regarding these designations.
Critical Habitat is designated within the Action Area for CCV Steelhead, CV Spring-run Chinook
Salmon, Winter-run Chinook Salmon, and sDPS North American Green Sturgeon, The Action
Area is also considered EFH for all runs of Chinook Salmon. Habitat requirements are similar for
CCV Steelhead and all runs of CV Chinook Salmon; therefore,these habitat features are
discussed together below.
5,1.1 Salmonid Critical Habitat in the Action Area
The physical and biological features of Critical Habitat for CCV Steelhead and CV Spring-run
Chinook Salmon present in the Action Area are freshwater rearing habitat, freshwater
migration corridors, and spawning habitat. As described above (Chapter4), the Lower Feather
River is dominated by urban and agricultural land use, with extensive levees in the lower
watershed, while the upper reaches still contain side channels, riffles, runs and pools that
function well as salmonid habitat. Features such as functional floodplains and other off-
channel salmonid rearing habitat are rare except under high flows. Floodplain habitats within
the Lower Feather River corridor have been modified or converted for uses such as agriculture,
gravel and gold mining, water impoundments, increased water diversions, and levees. These
major actions and other events have led to the deterioration of riparian and aquatic habitat
conditions. The Lower Feather River is largely disconnected from historic floodplains, providing
little opportunityfor seasonally inundated terrestrial vegetation and off-channel areas that are
important forjuvenile salmonids; as a result, rearing habitat is potentially a limiting factor in
the Lower Feather River and in the Action Area (Cavallo et. al 2003). Instream cover is patchy in
the main channel, but along the river margins there is instream woody material and in several
side channels overhead cover is provided by low-growing riparian vegetation within narrow
riparian corridors. Despite the anthropogenic impacts that have reduced the quality and
quantity of juvenile salmonid rearing habitat in the Lower Feather River, Chinook Salmon and O.
mykiss successfully spawn and rear within the Action Area (Mercer 2012).
The Lower Feather River within the Action Area is used as a migration corridor for adult and
juvenile CV Spring-run Chinook Salmon and CCV Steelhead. The majority of juvenile Spring-run
Chinook Salmon emigrate as fry from the Lower Feather River (Bilski and Kindopp 2009; Mercer
2012). However,juvenile Spring-run Chinook Salmon have also been documented to hold and
42
rear for an extended period of time in the Lower Feather River before emigrating (Bilski and
Kindopp 2009; Mercer 2012).
5.1.2 Pacific Coast Salmon Essential Fish Habitat in the Action Area
Chinook Salmon EFH is present within the Action Area (PFMC 2014). All four major components
of Chinook Salmon EFH are found in the Action Area: 1) spawning and incubation, 2)juvenile
rearing, 3)juvenile migration corridors, and 4) adult migration corridors and holding habitat. As
mentioned above, Chinook Salmon spawn and rear in the entirety of the Action Area (Sommer
et. al 2001 and Cavallo et. al 2003). The Lower Feather River within the Action Area also serves
as a migration corridor for juvenile and adult salmon and provides holding habitat for adult
salmon (Cavallo et. al 2003).
There are three EFH Habitat Areas of Particular Concern present in the Action Area: 1) complex
channels and floodplain habitats, 2)thermal refugia, and 3) spawning habitat. Although there is
LWD in the Lower Feather River which adds to habitat complexity,the lowest density of LWD
was found in habitat most likely to be used by Chinook Salmon, from the TAO to the Fish Barrier
Dara (Sommer et. al 2001). Chinook Salmon,habitat in the Lower Feather River from the Fish
Barrier Dam to the bottom of the LFC is dominated by coarse dredge tailings in the bed and
banks. There are some complex channels with riffles, point bars, raid-channel islands, and
multiple channels believed to be left over from pre-Oroville Dam hydraulic conditions; however,
these features are generally armored by cobbles and boulders (CDWR 2004). Further
downstream, levees constrict the channel, only allowing access to floodplain areas such as the
Oroville Wildlife Area and Sutter Bypass in high flow events when water overtops a weir,
limiting the availability of these areas to rearing juvenile Chinook Salmon. A mesohabitat study
was completed by CDWR from Oroville downstream to Honcut Creek above Yuba City, located
in the HFC. The CDWR study found that there is 61,333,019 ft'of available habitat composed
mostly of pool and glides, with few backwaters and runs. Juvenile Chinook Salmon have been
observed rearing in this area, occupying different reaches as they mature and progress through
different parts of their life-history.
Water temperature in the Lower Feather River within the Action Area very rarely reaches levels
that are stressful for Chinook Salmon due to NMFS temperature criteria, managed by CDWR to
maintain suitable temperatures for Spring-run Chinook and CCV Steelhead from June 1-
September 30, at Robinson's Riffle (RM 61,6) (CDWR 2004)..As summer temperatures warm in
the High Flow Channel most juvenile salmonids are thought to have already emigrated from the
lower Feather River or are rearing in the Low Flow Channel. Therefore, salmonids are unlikely
to seek out thermal refugia in the main channel of the Lower Feather River within the Action
Area.
As mentioned above, Chinook Salmon spawning habitat is present within the Action Area and
Chinook Salmon have been documented to spawn at various locations within the Action Area,
both in the LFC and HFC (Sommer et. al 2001).
43
5.1.3 North American Green Sturgeon Critical Habitat in the Action Area
The primary biological features of Critical Habitat for Green Sturgeon sDPS within the Action
Area include food resources, migratory corridor, water quality, depth, substrate type or size,
sediment quality, and water flow. The Fish Barrier Dam is impassible to Green Sturgeon and
blocks access to historical sDPS Green Sturgeon spawning habitat (Mora et al. 2009). Green
Sturgeon sDPS eggs have been observed and collected below TAO, and successful spawning
below the Fish Barrier Dam was confirmed in 2017 (CDWR unpublished data). A study by
Bergman (2011) inventoried the potential holding and spawning habitat in the Lower Feather
River, and 13 sites were identified below Oroville'Dam. The rest of the Action Area has been
highly modified by anthropogenic activities and likely functions as juvenile rearing habitat and a
migratory corridor.
44
6 EFECTS OF THE ACTION
6.1 Significance Criteria
The significance criteria used to evaluate the response to the Oroville Spillway Incident's effect
on protected species is based on the potential of the Actions to adversely affect the species or
to reach levels where they cause take or destroy/adversely modify Critical Habitat. The criteria
have been applied to all determinations of effect for each impact mechanism discussed below.
The effects of the CDWR response to the Oroville Spillway Incident include direct and indirect
effects. Direct effects are those that occur as a direct result of the response. Indirect effects
are defined as "those effects that are caused by or will result from the response and are later in
time, but are still reasonably certain to occur" [50 CFR §402.02].
Potentially adverse effects from the Oroville Spillway Incident response to CV Spring-run
Chinook Salmon, CCV Steelhead, Winter-run Chinook Salmon, and North American Green
Sturgeon sDPS and their designated Critical Habitat are primarily related to (1) suspended
sediment mobilization from dredging the Thermalito Diversion Pool and operating the FCO and
Emergency spillways, and (2) rapid flow ramping. Potentially adverse effects to CV Spring-run
Chinook Salmon and CCV Steelhead also include effects related to emergency operations at the
FRFH. Table 4 summarizes all potential impacts from management actions associated with the
Oroville Spillway Incident that are addressed in this document. All direct, indirect, and
cumulative effects are discussed below in detail.
Table 4. Potential adverse effects from the Oroville Spillway Incident Response on Protected Species.
z
x .e
Dredging;and Spillway Flow ramping ;
:.Hatch 2 f f
North American
Green Sturgeon X X None
(Acipenser
mediros0s
California Central
Valley Steelhead X X X
(Oncorhynchus
m kiss
Spring-run Chinook
Salmon X X X
(Oncorhynchus
fshaw scha
Winter-run Chinook
Salmon X X Bane
(Oncorhynchus
fshaw scha
45
6.2 Suspended sediment
The Oroville Spillway Incident resulted in approximately 1.7 million cubic yards of sediment
being eroded from the hillside containing the FCO and Emergency spillways. The majority of
eroded sediment was deposited in the Thermalito Diversion Pool at the base of the spillways.
The sediment was subsequently removed from the Thermalito Diversion Pool using heavy
equipment, primarily excavators, over several months. Some suspended sediment would have
also eroded and immediately mobilized into the lower Feather River during FCO spillway failure
and operation of the Emergency Spillway. The removal of debris in the Thermalito Diversion
Pool would have prolonged the period of elevated turbidity by re-suspending sediment in the
water column. Fish and other organisms in the Lower Feather River would have been exposed
to high levels of turbidity for a short duration as a direct result of the spillway failure and use of
the emergency spillway, and lower levels of increased turbidity for a long duration caused by
re-suspending sediment during removal of deposited sediment from the Diversion Pool.
Turbidity measurements as high as 974 NTUs and total suspended solids as high as 753 mg/L
were recorded at Auditorium Riffle in the Feather River LFC in the days following the incident
(CDWR unpublished data; Figure 9). Turbidity and total suspended solids gradually declined
over several days following the incident and then remained at values approximately between
30 and 70 NTUs and 10 and 30 mg/L, respectively,for a month thereafter(CDWR unpublished
data; Figure 9). Turbidity in the HFC peaked at 620 NTU on February 10, 2017 before
decreasing over the next week. When the Thermalito Diversion Pool was being dredged,
average turbidity 300 feet downstream from the dredging operation peaked at 639 NTU on
March 2, 2017. The turbidity data from within the Thermalito Diversion Pool and the limited
turbidity data from the Feather River downstream of the Fish Barrier Dam suggests that the
turbidity observed in the Thermalito Diversion Pool declines some before reaching the Fish
Barrier Dam, but elevated turbidity did continue into the Feather River below the Fish Barrier
Dam. Comparing turbidity and flow data in the HFC between 2017 and a similar wet year, 2006
(when flows reached 80,000 cfs), suggests that the Oroville Spillway Incident and dredging
resulted in higher turbidity in the HFC than is typically observed in a wet year (Figure 10). In
2006, the highest turbidity observed in the HFC was 23.1 NTU, while in 2017 the highest
turbidity observed in the HFC was 620 NTU. Note also that flows in 2006 never exceeded
65,000 cfs in the low flow channel,while flows in 2017 were nearly double that observed in
2006 (Figure 8). Unfortunately, there is not more turbidity data available after the Oroville
Spillway Incident for the HFC and LFC, but turbidity was dropping very rapidly as flows reduced
after the emergency spillway was over-topped. Turbidity dropped from 620 NTU on February
10, to 32 NTU on February 18, 2017. Turbidity in the Thermalito Diversion Pool generally
remained above 20 NTU until early April, suggesting that turbidity in the Feather River
downstream was also elevated until early April. Turbidity in the Thermalito Diversion Pool
continued to decline after early April until early June when it leveled off and generally remained
at values between 3 and 7 NTU.
46
1000.0 ..
X 4o HFC
LFC
AX A DP
100.01
<DP 300'ds.
Dredging
X X All
10.0 X, XX
rK
�N
1.0 _.... _.- ... _..._
20-Jan 9-Feb 1-Mar 21-Mar 10-Apr 30-Apr 20-May 9-Jura 29-Jun 19-Jul 8-Aug 28-Aug
Date
Figure 9. Turbidity(NTU)measured in the Feather Enver in the High Floe Channel(HFC), Low Flow
Channel(LFC), Diversion Pool(DP), and UP 300 ft downstream of the dredging in 2017. Note log scale on
y-oxis for turbidity.
47
140,000 1000.0
Spillway i� Emergency 2006 flaw
120,000 incident spillway used 2017 flow
2006 turbidity
2017 turbidity w 100,0
100,000
80,000 � � z
10.0
M 60,000
k AAL
A i
i
40,000
A - 1.01
A
20,000
21-Nov 11-Dec 31-Dec 20-Jan 9-Feb 1-Mar 21-Mar 10-Apr 30-Apr 20-May
Date
Figure 10. Streamflow(cfs)and available turbidity(NTU)data for the High Flow Channel in 2006 and
2017. Nate log scale on secondary y-axis for turbidity.
High concentrations of suspended sediment can have both direct and indirect adverse effects
on salmonids. The severity of these adverse effects depends on the sediment concentration,
duration of exposure, life history timing, and sensitivity of the affected life stage. Increases in
suspended sediment above the background level related to the Oroville Spillway Incident could
have potentially affected special-status fish and their habitat by(1) impeding adult holding and
spawning, and (2) impairing juvenile survival and rearing behavior. The increased turbidity in
the lower Feather River downstream of the Fish Barrier Dam had potentially adverse effects on
CV Spring-and Winter-run Chinook.Salmon, CCV Steelhead, and sDPS Green Sturgeon. The
timing of increased turbidity from the Oroville Spillway Incident overlaps with the presence of
rearing and migrating juvenile CV Spring-and Winter-run Chinook Salmon and CCV Steelhead,
upstream migrating adult CV Spring-run Chinook Salmon, and spawning CCV Steelhead. In
addition, the Oroville Spillway Incident suspended sediment impacts overlap with upstream
migration, spawning, and rearing of sDPS Green Sturgeon. Specific potential affects to each life
stage are discussed in greater detail below.
6.2.1 Adult Migration, Holding, and Spawning
Spring-run Chinook Salmon typically arrive at FRFH between mid-May and June (NMFS 2016;
Table 3). CV Spring-run Chinook Salmon hold in large pools, mainly in the LFC upon arrival and
through the summer before spawning in the fall (NMFS 2016). Adult CCV Steelhead typically
enter the Feather River from September to November and then hold until spawning (NMFS
48
2016). Adult CCV Steelhead begin spawning in the Lower Feather River in late December, peak
in late January and spawning is complete by the end of March (Cavallo et al. 2003; Hartwigsen
and Reid 2009). Adult sDPS Green Sturgeon typically start entering the Feather River in
February, hold before spawning, with spawning occurring from April through June (NMFS
2016). Therefore, some upstream migrating and holding adult CV Spring-run Chinook Salmon,
holding and spawning adult CCV Steelhead, and upstream migrating and holding sDPS Green
Sturgeon were exposed to elevated turbidity resulting from the Oroville Spillway Incident
response.
CV Spring-Run Chinook: Previous studies suggest that adult salmonids may be the life stage
least impacted by elevated suspended sediment levels (Bash et al. 2001). Elevated turbidity
does not appear to directly interfere with homing, although in extreme cases adult salmonids
may stray from natal streams which have very high suspended sediment concentrations (Quinn
and Fresh 1984). Elevated turbidity can, however, delay adult upstream migration and adult
salmonids may seek out turbidity refugia (Bash et al. 2001). Several studies have documented
active avoidance of turbid areas by adult salmonids (Sisson and Bilby 1982; Lloyd 1987; Servizi
and Martens 1992; Sigler et al. 1984). Adult CV Spring-run Chinook Salmon may have
attempted to behaviorally avoid the elevated turbidity by seeking out less turbid locations.
However, turbidity experienced in 2017 during adult migration of CV Spring-run Chinook
Salmon were approximately 10 NTU or less (April-June), similar to those experienced in 2006
and not a level expected to cause significant delay or adult avoidance. Tributaries and areas of
emerging subsurface flow may be used as turbidity refugia (Maslin et al. 1996; CFS unpublished
data). However, there are few tributaries to the Lower Feather River. The main tributaries, the
Yuba and Bear rivers, were turbid during this time as well, but were likely less turbid than the
Lower Feather River during peak turbidity immediately following the Oroville Spillway Incident.
Given the low probability of adult Spring-run Chinook Salmon presence during the peak of the
incident when turbidity was elevated, any adverse effect would be insignificant and therefore
not likely to adversely affect CV Spring-run Chinook.
CCV Steelhead: CCV Steelhead would have largely arrived on the spawning grounds prior to the
Oroville Spillway Incident because peak spawning occurs in January. However, some portion of
the spawning population likely experienced high levels of suspended sediment during the
Oroville Spillway Incident and the incident response and elevated turbidity may have had an
adverse effect on CCV Steelhead egg fertilization. A laboratory study determined that there is a
negative relationship between suspended sediment concentration and egg fertilization in
Sockeye (O. nerka) and.Coho Salmon (O. kisutch, Galbraith et al. 2006) and this relationship
likely is similar for other salmonids.Therefore, CCV Steelhead spawning during elevated
suspended sediment concentrations in the Lower Feather River may have had reduced egg
fertilization. Suspended sediment levels were high during the assumed second half of CCV
Steelhead spawning and therefore may have reduced fertilization rates. However, Steelhead
evolved to spawn during winter storm events where turbidities could remain high for some
time. Young-of-the-year Steelhead were also observed in the summer of 2017 during snorkel
surveys (CDWR unpublished) so some successful spawning did occur. Given the evolved life-
49
history of Steelhead and information currently available, increased turbidity may have affected
spawning, but was not likely to adversely affect spawning success.
Southern DPS Green Sturgeon: Adult Green Sturgeon were detected in the system as early as
January 24 near Shanghai Bend. However, based on several years of unpublished telemetry
data, the peak of sturgeon migration into the Feather River generally occurs after March 15, so
it is likely that only a small fraction of the sturgeon population was present during the Oroville
Spillway Incident and therefore any adverse effects would likely arise from dredging in the
Diversion Pool. Sturgeon evolved under high turbidity conditions and actively avoid areas of
low turbidity (Cech and Doroshov 2004). They have adaptations such as barbels and
electroreceptors that allow them to feed irrespective of water turbidity (LeBreton et al. 2006).
Thus, it is unlikely that adult sDPS Green Sturgeon were adversely affected by elevated turbidity
during the Oroville Spillway Incident or the response to the incident during their migration to
and holding on the spawning grounds.
6.2.2 Eggs and Larvae
Southern DPS Green Sturgeon: Southern DPS Green Sturgeon spawning in the Feather River
occurs from April through June, with larvae hatching from eggs within 6 to 8 days after
fertilization (NMFS 2016). Approximately 10 days post hatch, larval Green Sturgeon start
exogenous feeding and begin to disperse downstream (NMFS 2016).
Fine sediment produced by the Oroville Spillway Incident that deposited in sDPS Green
Sturgeon spawning habitat in the Lower Feather River may have negatively impacted embryo
and larval survival; however, little is known about the impact of suspended sediment and
deposited fine sediment on Green Sturgeon eggs and larvae. Studies of fine sediment impacts
to closely related and co-occurring White Sturgeon have documented adverse effects. For
example, White Sturgeon recruitment failure in the upper Columbia River(McAdam 2015) and
the Nechako River (McAdam et al. 2005) is believed to be a result of egg and embryo mortality
due to increased fine substrates at spawning sites. In a laboratory experiment, fine sediment
cover significantly reduced White Sturgeon embryo survival and embryo survival was negatively
correlated with duration of fine sediment cover (Kock et al, 2006). Larval White Sturgeon
appear to prefer the small interstitial spaces provided by small gravel, as this refuge habitat
decreases predation by sculpins (McAdam 2015). Spawning substrate surveys at several sDPS
Green Sturgeon spawning locations in the Sacramento River found that eggs generally collected
in pockets of small to medium gravel within larger substrate (Poytress et al. 2011). Another
study of Sacramento River sDPS Green Sturgeon spawning habitat suitability study found that
preferred spawning substrate was gravel and sand (Wyman et al. 2017). Green Sturgeon
spawning habitat studies in the Sacramento River and studies on the effect of fine sediment on
white sturgeon embryo and larval survival suggest that Green Sturgeon embryos, larva, and
their habitat may have been negatively impacted if the Oroville Spillway Incident produced fine
sediment that accreted on their spawning habitat.
50
The majority of spawning likely occurred while flows were higher in April and May when
detection of eggs and larvae were harder to document due to the dilution effect from the large
volume of water that was being sampled. It is very likely that conditions in the LFC were close to
optimal for Green Sturgeon spawning at this time. The spawn timing is supported by two
milting male Green Sturgeon CDWR tagged in early May which indicates adults were already in
spawning condition.
There was likely little impact on sturgeon embryo and larval survival or on Critical Habitat
during April and May, The high flows in the LFC in April and May likely kept fine sediment from
settling out in the spawning area and instead may have provided a positive effect. The tail end
of the spawning season may have been adversely affected by suspended sediment settling after
a flow decrease in late May. It was noted during egg and larval sampling during June that
sediments were not swept out of the area as rapidly and there was a larger concentration of
particulates in samples. However, the eggs appeared in good condition since they were well
developed and did not have any fungal growth on them; although this is based on a very small
sample size obtained on a single day. Larval sturgeon collected in June were fairly small (22-27
mm) and may have been impacted if particulates accumulated in the interstitial spaces used for
cover or in the open spaces in which they feed. Suspended sediment may have affected, but
was not likely to adversely affect sDPS Green Sturgeon spawning and egg to fry/larvae survival
because turbidity and suspended sediment concentrations had fallen by April when spawning
likely began (CDWR unpublished data).
CCV Steelhead: CCV Steelhead spawning in the Lower Feather River primarily occurs from late
December through March, with egg incubation from approximately December through April,
and alevin emergence from approximately March through May (NMFS 2016). And although
turbidity was quite high during primary egg incubation, flows were also very high and fairly
sustained throughout the spring. It is probable that any suspended sediment would have
carried far below the primary Steelhead spawning areas in the LFC before settling out. CDWR
observations of spawning gravel areas known for CCV Steelhead spawning saw no signs of
sedimentation, but rather normal signs of gravel movement after a relatively high flow event.
Some areas, however, did fill in from gravel movement while other areas scoured, again typical
of an alluvial system after a high flow event. The movement of alluvial gravel is not considered
an effect of the spillway response because this would have occurred without the Oroville
Spillway Incident and is considered background information. Eggs that did not scour or become
dewatered may have been affected, but were not likely adversely affected by suspended
sediment from the Oroville Spillway Incident or response to the incident.
6.2.3 Juvenile Rearing
Southern DPS Green Sturgeon: Little is known about Green Sturgeon early life history in the
Feather River but data from 2011 through 2018 provides insight. Based on larval catch in the
LFC in 2017 and the HFC during 2018 (A. Seesholtz, pers. comm.),juveniles could likely be found
throughout the river. Larvae likely metamorphose into juveniles beginning as early as late April.
51
Assuming they would exhibit the same behavior as the juveniles in the Sacramento River (B.
Poytress, pers. comm.), the majority would outmigrate in the late fall/early winter. Juvenile
sturgeon evolved in turbid settings so periods of increased turbidity during the high spring flows
did not hamper their ability to find food. By early June,turbidity levels had dropped
significantly (i.e., 4- 10 NTU). High spring flows swept away the suspended sediments which
might fill in the interstitial spaces used for cover from predators. There were no effects on
Green Sturgeon juveniles from increased suspended sediment.
CV Spring-run Chinook, Winter-run Chinook, and CCV Steelhead: Feather River CV Spring-run
Chinook Salmon alevins emerge from the gravel in November and December (NMFS 2016). The
majority of juvenile CV Spring-run Chinook Salmon in the Lower Feather River emigrate as fry,
with fry emigration peaking in December and then slowly declining from January to March
(Bilski and Kindopp 2009). A small number of CV Spring-run Chinook Salmon remain in the
Lower Feather River before emigrating in the spring and an even smaller number appear to
emigrate in the winter as yearlings (Bilski and Kindopp 2009; CDWR unpublished data).
Recent research provides evidence that juvenile Winter-run Chinook Salmon use the Lower
Feather River as non-natal rearing habitat although the spatial extent of this use is unknown
(Phillis et al. 2017). However, it is unlikely that non-natal rearing Winter-run would ascend
more than a few miles into the lower Feather River, significantly minimizing their potential
exposure to the higher levels of turbidity experienced in the upper river.
The capture of juvenile CCV Steelhead in Lower Feather River RSTs primarily occurs in March
and April, with considerably lower catch in May and June (Bilski and Kindopp 2009). The
majority of captured juvenile CCV Steelhead were less than 150 mm FL, with very few larger
smolt sized fish captured (Bilski and Kindopp 2009). Rearing juvenile CCV Steelhead are present
in the Lower Feather River year-round (Seesholtz et al. 2004).
Short-term increases in suspended sediment may disrupt feeding activities or result in
avoidance or displacement of fish from preferred habitat. Juvenile salmonids have been
observed to avoid streams that are chronically turbid (Lloyd 1987) or move laterally or
downstream to avoid turbidity plumes (Sigler et al. 1984). Bisson and Bilby (1982) reported
that juvenile Coho Salmon avoid areas with turbidity exceeding 70 NTU. During periods of
elevated turbidity in mainstem rivers,juvenile salmonids may find refuge in less turbid non-
natal tributaries including intermittent streams (Mallin et al. 1996). Sigler et al. (1984) found
that prolonged exposure to turbidities between 25 and 50 NTUs resulted in reduced growth
and increased emigration rates of juvenile Coho Salmon and CCV Steelhead compared to
controls. These findings are generally attributed to reductions in reactive distance, the ability
of salmon to see and capture prey, in turbid water (Waters 1995). In laboratory studies,
juvenile salmonids have been observed to transition from drift feeding to benthic feeding
during periods of elevated turbidity (Gregory and Northcote 1993; Rowe et al. 2003). However,
some field studies suggest that juvenile salmonids will continue to drift feed during turbid
conditions despite the reduced reactive distance (Arndt et al. 2002; White and Harvey 2007).
52
Chronic exposure to high turbidity and suspended sediment may also affect growth and survival
by impairing respiratory function, reducing tolerance to disease and contaminants, and causing
physiological stress (Waters 1995). Berg and Northcote (1985) observed changes in social and
foraging behavior and increased gill flaring (an indicator of stress) in juvenile Coho Salmon at
moderate turbidity (30-60 NTUs). In that study, behavior returned to normal quickly after
turbidity was reduced to lower levels (0-20 NTUs). Turbidity in the Lower Feather River appears
to have remained at elevated levels for over two weeks (Figure 10), which may have reduced
foraging success and growth for juvenile salmonids that remained in the Action Area, as has
been observed in previous studies (Sigler et al. 1984).
Juvenile CV Spring-run Chinook Salmon and CCV Steelhead may have attempted to behaviorally
avoid the elevated turbidity by seeking out less turbid locations; several studies have
documented active avoidance of turbid areas by juvenile salmonids (Bisson and Bilby 1982;
Lloyd 1987; Servizi and Martens 1992; Sigler et al. 1984). Tributaries and areas of emerging
subsurface flow may be used as turbidity refugia (Maslin et al. 1996; CFS unpublished data).
However, there are few tributaries to the Lower Feather River and the main tributaries, the
Yuba and Bear rivers, were likely turbid during this time as well, but may have been less turbid
than in the Lower Feather River. In alluvial rivers, water can move subsurface through gravel
bars and then emerge on the downstream side as relatively clear water. Fish may actively seek
out these locations to avoid elevated turbidity (CFS unpublished data). Alternatively,juvenile
CV Spring-run Chinook Salmon, CCV Steelhead, and non-natal rearing juvenile Winter-run
Chinook Salmon may have migrated downstream in response to elevated flows and turbidity.
Juvenile CV Spring-and Winter-run Chinook Salmon that emigrated in response to elevated
turbidity may have located high quality rearing areas on downstream floodplains inundated by
high flows (Sommer et al. 2001; Katz et al. 2017). Juvenile CCV Steelhead may also benefit from
floodplain rearing opportunities, but this has not been well studied. Juvenile salmonids forced
to leave protective habitat due to elevated turbidity may have increased their exposure to
predators. However, the increased predator exposure may have been offset by greater cover
provided by elevated turbidity and access to shallower floodplain habitats (Gregory and Levings
1998). Juvenile salmonids may also use turbidity as a cue for downstream migration, likely due.
to the cover from predators that it provides (Jensen et al. 2012). However, turbidity and flow
are highly correlated in most river systems, so it is uncertain which factor provides the
migration cue, but in 2017 both factors were likely operating.
Deposited fine sediment can decrease production of the macroinvertebrate prey of juvenile
salmonids (Wu 2000; Chapman 1988; Phillips et al. 1975; Suttle et al. 2004; Colas et al. 2013).
Rivers with high fine sediment content tend to have low densities of macroinvertebrates and be
taxon poor (Larsen et al. 2011; Buendia et al. 2013; Descloux et al. 2013). Low
macroinvertebrate density from high fine sediment concentration leads to less available food
for juvenile salmonids with potential impact on growth and survival (Suttle et al. 2004).
53
Suspended sediment introduced into the Lower Feather River as a result of the Oroville Spillway
Incident responses and Thermalito Diversion Pool dredging were likely to adversely affect CV
Spring-run Chinook Salmon and CCV Steelhead. Juvenile CV Spring-run Chinook Salmon and
CCV Steelhead juveniles or yearlings that remained in the Lower Feather River to rear during
the elevated suspended sediment may have experienced reduced growth as a result of
impaired reactive distance to prey, impaired respiratory function, reduced tolerance to disease,
and physiological stress. Juvenile Winter-run Chinook Salmon may have been affected, but
were not likely adversely affected by elevated suspended sediment. Winter-run probably only
use the lowermost portions of the Lower Feather River(mostly likely the lowermost 5 miles)
and were therefore able to leave the system quickly if conditions became unsuitable.
6.3 Flow reductions
Between February and June 2017, four periods of rapid flow reduction from the FCO Spillway
occurred. Although these rapid flow reductions were authorized by the USACE, there was
concern about the possibility of stranding special status species in off-channel habitats. These
flow reductions occurred on February 27, March 27, May 1, and May 19, 2017 (White et al.
2017). Potential effects of these four periods of rapid flow reduction are described below.
6.3.1 Straying
CV Spring-run Chinook Salmon: Spring-run Chinook Salmon enter the Feather River and hold
from March through October with a peak immigration in May and June. Thus, three of the four
ramping periods overlapped with the adult migration period. Strongly pulsed flows during
ramping may have attracted spring run from other basins into the Feather River. However,
flows were also high in the Sacramento River and Yuba River during this period suggesting
olfactory cues from these systems would remain strong during pulsed Feather River flows. The
lower Feather River experienced high flows throughout the spring and during the final
significant flow drop on May 19 flows still remained significantly high enough (well over 10,000
cfs)to provide attraction flows. It is likely that flow ramping had no effect on straying of CV
Spring-run.
CCV Steelhead: Adult CCV Steelhead enterthe Feather River between August and December
and spawning occurs between December and March with a peak in January(Hartwigsen and
Reid 2009; Kindopp et al. 2003).
All CCV Steelhead produced at CV hatcheries are marked with an adipose fin clip but are not
tagged to identify hatchery of origin. Thus, it is unknown if the incident caused straying of out-
of-basin hatchery CCV Steelhead into the Feather River or caused Feather River fish to stray to
other basins. However, as described above, the timing of the resulting flow pulses makes it
unlikely that straying of CCV Steelhead occurred since nearly all CCV Steelhead were already on
the spawning grounds when the incident began, and the FRFH had completed their 2017 CCV
Steelhead spawning at least a week before the incident occurred. Although the end of the
54
spawning period overlapped with the first ramping event, most fish should have already arrived
on the spawning grounds, therefore flow reductions were not likely to adversely affect CCV
Steelhead straying.
Southern DPS Green Sturgeon: Sturgeon were detected in the system as early as January 24
near Shanghai Bend. However, based on several years of unpublished telemetry data, the peak
of sturgeon migration into the Feather River generally occurs after March 15, so it is likely that
only a small fraction of the sturgeon population was present during the operation of the
Emergency spillway and FCO spillways. Any adverse straying effects would thereby arise from
the four down ramping events.
The exact drivers that stimulate Green Sturgeon to find and ascend the Feather River are
unknown. Data is also limited on how Green Sturgeon decide which river they will ascend and
at exactly what time. However, in years of higher flows there appears to be increased
aggregations of adults and spawning has been observed at two locations in the lower Feather
River. Given the high flows experienced during the majority of 2017 (spring), even with the 4
ramp down events, it is likely that conditions were ideal in the lower Feather River for Green
Sturgeon to ascend due to significant attraction flows. Additionally,the flow "split" between
the Feather and Yuba Rivers would have been, at most times, favorable to the Feather River,
likely attracting more fish into its upper reaches. The boulder weir at Sunset Pumps would have
also been inundated for the majority of the migration season, making passage very easy. And a
large aggregation of sturgeon (believed to mostly be Green Sturgeon based on the two
individuals captured) was observed near the Fish Barrier Dam, with spawning documented
shortly thereafter. For these reasons, flow reductions associated with the spillway response did
not have an adverse effect on Green Sturgeon.
6.3.2 Stranding
Stranding that occurred after the Oroville Spillway Incident was extensively surveyed,
documented, and evaluated by the CDWR Division of Environmental Services and Pacific States
Marine Fisheries Commission (White et al. 2017). Estimated total stranding is described for
each target species below, and summarized in Table 5. The range of values reported for each
target species originates from identifying the lowest and highest estimates reported of
stranded individuals across the total sampled area (Tables 6 and 16 of White et al. 2017). The
overall conclusion of the stranding report was that while the spatial and temporal extent of
stranding was considerable, overall mortality from stranding was probably very low for species
of concern. Additionally,the benefits conveyed to juvenile salmonid species via access to
floodplain resources in the sustained high-flow conditions were likely substantial. However, we
do not know the extent or impact of stranding in unobserved, rapidly-desiccated pools. It was
also not possible to effectively document potential stranding in the lowermost reaches of the
Feather River (RM 14 to RM 0) due to significant connectivity of very large ponds during much
of the stranding survey. However, eDNA sampling was conducted to identify Green Sturgeon
and salmonids stranded in larger ponds (White et al. 2017). Stranding overall was higher in the
55
high-flow channel than in the low-flow channel, although individual species' stranding
distributions differed.
Table.5. Observed and extrapolated numbers of special status species stranded in wet pools during the
Oroville Spillway Incident and resulting response actions. Subsequent high flows reconnected most wet
pools with the main channel.
Life Stage Target Species Observed stranded Extrapolated range stranded
Juvenile Spring-run Chinook Salmon 71 4817 -5380
Juvenile Winter-run Chinook Salmon 2 NA -0
Yearling Hatchery CCV Steelhead 19 1289 - 1631
Adult Hatchery CCV Steelhead 4 58 -268
Fry Natural Origin CCV Steelhead 1 70-87
Yearling Natural Origin CCV Steelhead 20 575 - 1355
Adult Natural Origin CCV Steelhead 10 145-676
Juvenile Green Sturgeon 0 NA
Adult Green Sturgeon 0 NA
All evaluated stranding was classified as having occurred in "wet pools" (i.e. ponds that retained
water for the duration of the sampling) or in "dry pools" (depressions which desiccated soon
after the high flow event occurred and were dry at the time of physical sampling). All
extrapolated numbers of stranded fish are estimated from taxa-specific sampling densities in
wet pools only, as the total area (ml) of dry pools in the affected area was not possible to
calculate. Mortality in dry pools was 100%, while mortality in wet pools ranged from 2.2 to
5.6%for salmonid species.
Southern DRS Green Sturgeon: No Green Sturgeon were detected when sampling for eDNA nor
were any detected using traditional gear in any pools sampled, wet or dry. Given, however,
that Green Sturgeon adults, eggs, larvae, and juveniles were likely present during the Oroville
Spillway Incident, there may have been insignificant affects, but no Green Sturgeon were likely
adversely affected from stranding associated with rapid flow ramping.
California Central Valley Steelhead:The timing of the first significant ramp-down coincided
with the end of the CCV Steelhead spawning window (late February). Fifty-four total CV
Steelhead, comprising both hatchery and natural origin and of all life stages, were found
stranded. Adult CCV Steelhead were concentrated in the LFC, while the majority of the 39
yearlings were found in the HFC, many of hatchery origin. A single fry-size CCV Steelhead was
sampled in the HFC during stranding surveys. It is unknown if adult CCV Steelhead found in
isolated pools were post-spawn kelts beginning to migrate downstream or if they were holding,
waiting for conditions to improve. Given they were captured after several high flow events it is
likely that they were in fact holding and not post-spawn emigrants. Regardless,juvenile,
yearling, and adult CCV Steelhead were adversely affected from stranding due to rapid flow
reductions in response to the Oroville Spillway Incident.
56
CCV Steelhead spawning in the Feather River generally begins in December, peaks in January
and trails off in late winter (Kindopp et al. 2003). It is likely that a large proportion of the 2017
CCV Steelhead redds had been constructed and embryos were incubating during the time of the
first flow ramping period. The majority of CCV Steelhead spawning occurs in the LFC and flows
in this reach averaged —32,000 cfs on the day prior to the incident and were also relatively high
during the peak month of January before the incident (up to 7,000 cfs). At these high flows,
CCV Steelhead were likely confined to spawning in Hatchery Side Channel and river margins as
depths and velocities moved away from spawning suitability criteria in more open, somewhat
unprotected areas (Kindopp et al. 2003). When flows from the spillway were stopped and flows
in the LFC returned to— 600 cfs, it is possible that redds constructed on the river margins were
stranded. However, Hatchery Side Channel would have remained relatively stable due to its
relative protection from high flows (up against the levee) and redds did remain viable in this
area. Snorkel surveys conducted in 2017 by CDWR identified over 50 young-of-the-year CCV
Steelhead in Hatchery Side Channel, indicating successful spawning and incubation did occur.
Embryos incubating in dewatered redds can continue to develop and survival of those embryos
depends on the length of time dewatered, developmental stage, and the environmental
conditions in the intragravel environment (Neitzel and Becker 1985). No surveys were
performed to evaluate redd stranding and flows did eventually increase above pre-incident
levels. However, flow fluctuations combined with the long period of minimum flows in the LFC
(> 7 days), resulted in possible stranding of CCV Steelhead redds that reduced embryo survival
or caused total loss of some redds. it is also unlikely that many CCV Steelhead were spawning
on the river margins at flows of approximately 7000 cfs due to the lack of suitable spawning
habitat at these flows. The low flow channel is heavily leveed and as flows increase much
above 3000 cfs, river margins simply become deeper and swifter. Furthermore, because CCV
Steelhead are iteroparous, they can postpone spawning and return to the ocean. Later
spawners (late February or later) may have elected to migrate back to the ocean to return in
later years when conditions may be more suitable. Given available information, CCV Steelhead
may have spawned in areas that later became dewatered and therefore some steelhead eggs
were likely adversely affected from stranding due to flow reductions in response to the Oroville
Spillway Incident.
Juvenile CV Spring-run and Winter-run Chinook Salmon: The Oroville Spillway Incident
occurred during a period of time when most juvenile Spring-run Chinook Salmon are expected
to be downstream of the Action area (CVPIA Comprehensive Assessment and Monitoring
Program data 2000-2015). The stranding that did occur for Spring-run Chinook Salmon was
largely concentrated in the high-flow channel, indicating that most fish had either emigrated
downstream prior to the event, or were transported downstream by high flows. Spring-run
juvenile Chinook Salmon were the second-most abundant run sampled during the event,
accounting for 1.6% of the total Chinook Salmon catch. Spring-run Chinook Salmon are typically
nearly 70 mm by late February, making them less vulnerable to stranding during this time of
year than Fall-run Chinook Salmon, on average. Most of the Spring-run Chinook Salmon
encountered were recovered alive (96%) from wet pools. Although the great majority of
57
Spring-run Chinook Salmon were found alive in wet pools and were likely reconnected to the
river when flows increased, some were found in dry pools and some would be expected to die
from predation or desiccation in quickly-drying wet pools. For these reasons Spring-run
Chinook salmon juveniles were adversely affected from stranding due to flow reductions in
response to the Oroville Spillway Incident.
While Winter-run Chinook Salmon are not known to spawn in the Feather River, two Winter-
run sized fish were collected from wet pools in the high-flow channel. These individuals were
more likely either the progeny of early-spawning Spring-run Chinook Salmon, or were Feather
River Fish Hatchery Fall-run Chinook Salmon that had been released into Lake Oroville during
prior years (White et al. 2017). Extrapolated stranding estimates were not available for Winter-
run juvenile Chinook Salmon. However, given that "true" Winter-run Chinook Salmon do not
spawn in the lower Feather River and are only known and suspected to rear in the lower-most
reaches, the individuals identified as Winter-run during the stranding surveys were not likely
Winter-run at all. Additionally, adipose fin clip status cannot distinguish Lake Oroville Fall-run
from other runs because Lake Oroville Fall-run are not currently adipose fin clipped or coded-
wire-tagged. Furthermore, the individuals collected were well upstream of expected Winter-
run non-natal rearing habitat,further evidence they were likely Fall-run displaced from Lake
Oroville during a spill event. For these reasons, Winter-run Chinook Salmon juveniles may have
been affected, but were not likely to be adversely affected from stranding due to flow
reductions in response to the Oroville Spillway Incident.
The extrapolated stranding estimate for adult Chinook Salmon was 29 individuals. This
estimate only applies to the LFC, where three individuals were recovered;two individuals were
sampled from the HFC, but area measurements were unavailable. The result is that total
stranding of adult Chinook Salmon, while likely not substantial, is probably slightly
underestimated forthe Oroville Spillway Incident response. Although "adult" Chinook Salmon
are included here because their run designation is unknown; it is likely that given their relatively
small size for Chinook salmon (White et al. 2017),these very small "adults"were 2-3-year-old
Fall-run Chinook Salmon planted in Lake Oroville in previous years that washed over one of the
spillways. Additionally, the timing of the stranding does not fit well with known life-histories of
anadromous Chinook Salmon in the Feather River. It is possible that some of these fish were
Late-fall run Chinook from Coleman National Fish Hatchery but given their small size that also
seems improbable. It is also extremely unlikely they would be CV Spring-run since there is no
data to suggest Feather River Spring-run arrive to holding areas in late February and early
March. For these reasons, adult Chinook Salmon were not affected from stranding due to flow
reductions in response to the Oroville Spillway Incident.
6.4 Feather River Fish Hatchery
CV Spring-run Chinook Salmon: In anticipation of adverse effects on juvenile Chinook Salmon at
the FRFH due to high turbidity following the Oroville Spillway Incident, approximately 2 million
Spring-run Chinook Salmon and 4.2 million Fall-run Chinook Salmon were moved to the Annex
58
facility, where water is sourced from a well and not affected by the sediment movement in the
Lower Feather River. In addition, a sedimentation channel was set up at the FRFH for the 2.5
million fish that remained at the main facility. During the evacuation period, FRFH staff
continued to mitigate for silt in the inland ponds. Medicated and probiotic feed and salt baths
were also employed to improve fish health at the FRFH during the Oroville Spillway Incident. A
blockage in the screens at the aeration tower at the FRFH prevented the use of the settling
ponds to decrease turbidity but, by the time the blockage occurred, turbidity had dropped to
less stressful levels.
In the early morning on May 10, 2017,the primary pump supplying well water to the Annex
facility failed, drastically reducing the water supply to the Annex facility raceways, killing
approximately 70,000 Fall-run Chinook Salmon juveniles, but no Spring-run. CDFW staff first
observed stressed Fall-run Chinook Salmon at 6:30 a.m. along with mortalities in the raceways
due to low dissolved oxygen levels. Hatchery staff immediately started supplying supplemental
oxygen to the raceways to keep fish alive. CDFW notified CDWR, which manages the wells, and
CDWR electricians made immediate repairs to restart the pump motor and resume the flow of
water. The rapid response of CDFW and CDWR employees likely saved thousands if not millions
more Fall-run Chinook Salmon at the Annex. In response to this event, CDFW and CDWR staff
developed additional redundancy measures to prevent future pump failures.
After fish were moved in response to the Oroville Spillway Incident,fish fed well and remained
in good condition at the FRFH and at the Annex. However, due to overcrowding at the Annex,
juvenile growth was slowed yet they were still larger than in-river cohorts (CDWR unpublished
2017). Spring- and Fall-run Chinook Salmon were implanted with coded wire tags (100%Spring-
run, 25% Fall-run) as part of normal monitoring associated with the FRFH. In July, all fish
remaining at the FRFH were moved to the Annex while repairs at the FRFH took place.
Spring- and Fall-run Chinook Salmon production goals are to release 2 and 6 million smolts
annually, respectively (CDWR unpublished 2017; HSRG 2012a; HSRG 2012b). In 2017,
approximately 5 million Fall-run Chinook Salmon and approximately 1.7 million Spring-run
Chinook Salmon were released (Table 6), representing 83% and 85% of the annual production
goal, respectively (CDWR unpublished 2017). In addition to the standard 6 million Fall-run
Chinook Salmon normally produced for mitigation, an additional 2 million fish were reared,
tagged, and released from the FRFH in the spring of 2018 (CDWR unpublished 2017).
59
Table 6. 2017 FRFH releases of Spring-and Fall-run Chinook Salmon.
Release Date Number Released Feather River Bay
Fall-Run Spring-Run
3/20/2017 1,054,757 x
4/4/2017 645,134 x
4/24/2017 521,106 x
4/26/2017 1,017,308 x
5/8/2017 509,119 x
5/11/2017 862,500 x
5/18/2017 725,162
5/19/2017 295,255 x
5/25/2017 528,912 x
5/26/2017 530,780 x
Total 4,990,142 1,699,891
CCV Steelhead: A filtration system was set up for 750,000 CCV Steelhead eggs that were not
moved from the FRFH due to space constraints and fragility of the eggs. The filtration system
for the eggs failed during the incident, so an alternate plan was put into place using a fire
hydrant as the source for egg water, which was then filtered for chlorine and combined with
raw water to decrease temperature and increase oxygen to the eggs. Even during the
evacuation period, FRFH staff continued to mitigate for silt in the incubation stacks. Eggs and
fry remained in good condition throughout the incubation and rearing season (CDWR
unpublished 2017). When space was available at the Annex, steelhead juveniles were moved
out of the main facility to allow for intensive cleaning of raceways. Upon completion of FRFH
repairs in August, CCV Steelhead were moved back to the FRFH for continued rearing.
In 2017 and 2018, approximately 663,000 CCV Steelhead were reared for release in winter
2018, approximately 213,000 more than required for normal mitigation (CDWR unpublished
2017). 182,000 were released into the Thermalito Afterbay at catchable and sub-catchable size
to promote a local fishery, although some unknown number of these fish are likely to return to
the river as adults in a few years, creating a contribution to the local spawning population. In
mid-February the remaining 481,000 yearlings, approximately 50,000 more than normal, were
released as part of the normal mitigation strategy into the Lower Feather River at Boyd's Pump
Boat Launch.
60
7 CONCLUSION
The Oroville Spillway Incident resulted in emergency response actions that had adverse, and
potentially adverse effects on special status species in the action area.
7.1 Suspended Sediment
7.1..1..1 Adult Migration, Holding, and Spawning
CV Spring-run Chinook Salmon: Given the low probability of adult Spring-:run Chinook Salmon
migrating during the peak of the incident when turbidity was elevated, any adverse effect
would be insignificant and therefore not likely to adversely affect CV Spring-run Chinook. Over-
summer holding of CV Spring-run occurs between May and September when turbidity levels
had dropped significantly. CV Spring-run spawning occurs in September and early October, also
well after turbidity levels had dropped. There was no effect on CV Spring-run migration,
holding, or spawning as a result of increased turbidity from the response to the Oroville
Spillway Incident.
CCV Steelhead:The migration of CV Steelhead was likely complete or nearly complete when
the Oroville Spillway Incident occurred so any affect would have been insignificant and not
likely to adversely affect CCV adult migration. Suspended sediment levels were high during the
assumed second half of CCV Steelhead spawning and therefore may have reduced fertilization
rates of CCV Steelhead during the end of the 2017 spawn. However, Steelhead evolved to
spawn during winter storm events where turbidities could remain high for some time. Young-
of-the-year Steelhead were also observed in the summer of 2017 during snorkel surveys (CDWR
unpublished) so some successful spawning did occur. Given the evolved life-history of
Steelhead and information currently available, increased turbidity may have affected spawning,
but was not likely to adversely affect spawning success of CCV Steelhead.
Southern DPS Green Sturgeon: Based on several years of unpublished telemetry data., the peak
of sturgeon migration into the Feather River generally occurs after March 15, so it is likely that
only a small fraction of the sturgeon population was present during the Oroville Spillway
Incident and therefore any adverse effects would likely arise from the dredging in the Diversion
Pool. Sturgeon evolved under high turbidity conditions and they actively avoid areas of low
turbidity (Cech and Doroshov 2004). They have adaptations such as barbels and
electroreceptors that allow them to feed irrespective of water turbidity(LeBreton et al. 2006).
Turbid conditions during spawning were likely ideal in 2017. Thus, it is not likely that adult sDPS
Green Sturgeon were adversely affected by elevated turbidity after the Oroville Spillway
Incident or the response to the incident during their migration, holding, or spawning.
61
7.1.1.2 Eggs and Larvae
Southern DRS Green Sturgeon: Although measurements of turbidity and suspended solids were
high during and immediately following the Oroville Spillway Incident, sustained flow pulses
>40,000 cfs in spring of 2017 may have flushed fine sediment deposited during the incident
response and reduced or eliminated potential impacts on Green Sturgeon spawning habitat.
Turbidity and suspended sediment had decreased.by April when Green Sturgeon spawning may
have started. Suspended sediment may have affected, but was not likely to adversely affect
sDPS Green Sturgeon eggs or larvae.
CCV Steelhead: Although turbidity levels were very high at times this typically corresponded
with high flows that would likely transport suspended sediment far downstream of CCV
Steelhead spawning habitat. Eggs that were not scoured or dewatered may have been
affected, but were not likely adversely affected by suspended sediment from the Oroville
Spillway Incident or response to the incident.
7.1..1.3 Juvenile Rearing
CV Spring-run and Winter-run Chinook Salmon and CCV Steelhead: Suspended sediment
introduced into the Lower Feather River as a result of the Oroville Spillway Incident responses
and Thermalito Diversion Pool dredging were likely to adversely affect CV Spring-run Chinook
Salmon and CCV Steelhead. Juvenile CV Spring-run Chinook Salmon and CCV Steelhead
juveniles or yearlings that remained in the Lower Feather River to rear during the elevated
turbidity may have experienced reduced growth as a result of impaired reactive distance to
prey, impaired respiratory function, reduced tolerance to disease, and physiological stress.
Although juvenile CV Spring-run and CCV Steelhead are known to spawn and rear in the lower
Feather River, Winter-run are not. Juvenile Winter-run Chinook Salmon may have been
affected, but were not likely adversely affected by elevated suspended sediment. Any non-
natal rearing Winter-run Chinook Salmon juveniles present during the response to the event
were likely in the lower-most reaches of the Feather River and would have had ample
opportunity to quickly emigrate if conditions became unsuitable. Elevated turbidity may have
also had positive effects for both runs of Chinook Salmon by providing increased cover during
juvenile emigration.
Southern DPS Green Sturgeon: Juvenile sturgeon evolved in turbid settings so periods of
increased turbidity during the high spring flows did not hamper their ability to find food. By
early June,turbidity levels had dropped significantly (i.e., 4 - 10 NTU). High spring flows swept
away the suspended sediments which might fill in the interstitial spaces used for cover from
predators. There were no effects on Green Sturgeon juveniles from increased suspended
sediment.
62
7.2 Flow Reductions
7.2.1.1 Straying
CV Spring-run Chinook Salmon: Based on the timing of the four flow reductions in response to
the Spillway Incident, straying was not likely to adversely affect CV Spring-run Chinook Salmon.
Additionally, high flows in the Feather River through the Spring-run Chinook Salmon migration
period certainly reduced migration slowdowns like the boulder weir at Sunset Pumps.
Additionally, when a flow differential exists (higher Yuba flows in spring) between the Feather
and Yuba Rivers it is thought by some to play a role in potential straying of FR hatchery origin
Chinook Salmon into the Yuba River. With sustained high flows being released from the FR
throughout the spring this flow differential would not have been "in effect" in 2017, creating
ideal conditions for Feather River origin Spring-run to find and ascend the lower Feather River,
making it to the hatchery or LFC holding areas.
Southern DPS Green Sturgeon: Based on several years of unpublished telemetry data, the peak
of sturgeon migration into the Feather River generally occurs after March 15, so it is likely that
only a small fraction of the sturgeon population was present during the operation of the
Emergency and FCO spillways.
Given the high flows experienced during the majority of 2017 (spring), even with the four-ramp
down events, it is likely that conditions were ideal in the lower Feather River for Green
Sturgeon to ascend due to significant attraction flows. The boulder weir at Sunset Pumps
would have also been inundated for the majority of the migration season, making passage very
easy. And a large aggregation of sturgeon (believed to mostly be Green Sturgeon based on the
two individuals captured) was observed near the Fish Barrier Dam, with spawning documented
shortly thereafter. For these reasons,flow reductions associated with the spillway response did
not have an adverse effect on Green Sturgeon.
7.2.1.2 Stranding
CV Spring-run and Winter-run Chinook Salmon and CCV Steelhead: A large proportion of
juvenile CV Spring-run Salmon had likely already migrated out of the Action Area but some
juvenile and yearling CCV Steelhead were actively rearing during the four-rapid ramp down
events, resulting in the stranding of juvenile and adult salmonids in off-channel pools.
Stranding surveys revealed low mortality of juvenile and adult salmonids in wet pools; however,
stranding estimates in dry pools could not be calculated and mortality would have been 100%
in these areas and in pools that were wet upon inspection but were likely to desiccate rapidly.
Most of the wet pools were reconnected to the main channel with subsequent high flows and
provided opportunities for stranded fish to return to the river. Thus, fish may have actually
obtained a growth benefit from access to these floodplain habitats. The observed and
expected mortality indicates that stranding due to rapid flow ramping was likely to adversely
affect juvenile CV Spring-run Chinook Salmon and juvenile,yearling, and adult CCV Steelhead.
63
Additionally, some CCV Steelhead embryos were likely to be adversely affected due to
stranding of redds from rapid flow ramping.
Southern DPS Green Sturgeon: No Green Sturgeon were detected when sampling for eDNA nor
were any detected using traditional gear in any pools sampled, wet or dry. Given, however,
that Green Sturgeon adults, eggs, larvae, and juveniles were likely present during the Oroville
Spillway Incident, there may have been insignificant affects, but no Green Sturgeon were likely
adversely affected from stranding associated with rapid flow ramping.
7.3 Feather River Fish Hatchery
Management actions taken to ensure survival of eggs and juveniles at the FRFH from the
Oroville Spillway Incident were not likelyto adversely affect eggs or juvenile CCV Steelhead.
Although eggs and juveniles were moved and handled more than normal and a clean and stable
water supply was difficult to achieve, no significant mortality occurred and production was
significantly increased beyond normal.
Juvenile Spring-run Chinook Salmon rearing at the FRFH and Annex may have been affected,
but were not likely to be adversely affected from high suspended sediment and actions taken to
manage suspended sediment arising from the Oroville Spillway Incident. Appropriate measures
were taken to maintain water quality at both facilities and although growth may have slowed, it
was discountable and normal production levels were achieved.
Juvenile Spring-run Chinook Salmon were not adversely affected when a pump failed at the
Thermalito Annex, causing low oxygen levels and subsequent mortality to approximately 70,000
Fall-run Chinook Salmon juveniles (P. Crawshaw Pers comm).
7.4 Critical Habitat and Essential Fish Habitat
Critical Habitat is defined as specific locations within the geographical area occupied by federal
ESA listed species in which are found those physical and biological features essential to the
conservation of the species and which may require special management considerations or
protections (ESA section 3(5)(A)(1)). EFH applies to Pacific salmon and other commercial fish
species and is defined as the aquatic habitat necessary for spawning, breeding, feeding, or
growth to maturity.
Critical Habitat is designated within the Action Area for CCV Steelhead, CV Spring-run Chinook
Salmon, Winter-run Chinook Salmon, and sDPS North American Green Sturgeon. The Action
Area is also considered EFH for all runs of Chinook Salmon. There is no indication that rapid
flow ramping or increased suspended sediment resulted in an adverse effect to or destruction/
adverse modification of Critical Habitat for listed species or EFH for Chinook Salmon.
64
Adverse modification of CH or EFH would most likely include significant adverse modifications
to:
• Water temperature,
o No changes in water temperature were observed during or after the response actions
and CDWR continued (and continues)to operate to the 1983 Agreement and NMFS
2004 BO temperature requirements.
• Spawning and rearing habitat,
o No changes in spawning or rearing habitat beyond those expected after a normal high
flow event have been observed. Gravel placed in 2014 to augment salmonid spawning
was mobilized during high flows but much of that material was deposited elsewhere in
the lower Feather River.There were also no signs of unusual or adverse sedimentation
in spawning gravels.This may be due to the long duration high flows experienced
throughout the spring of 2017 that likely mobilized any fine sediment that may have
been deposited when flows were low or near minimums while dredging was still
occurring and turbidity was still high. By the time flows began to drop significantly,
turbidity levels were also dropping quickly.
• Connectivity of habitat,
o No connections to habitat were adversely modified from response actions.Although
rapid down ramping created stranding of individuals,access to floodplain habitat was
significant in 2017 due to longer sustained high flows. Higher than normal late-winter
and spring flows also likely enhanced the ability of Green Sturgeon and CV Spring-run
Chinook to pass the Sunset Pumps rock weir to quickly access holding and spawning
habitat.
• Gravel recruitment
o There is no information to suggest that gravel recruitment was adversely modified by
response actions. Bedload movement analysis shows that gravel recruitment and
movement would have occurred under a no-incident scenario, probably very similar to
amounts observed during the incident. Observations of salmonid spawning habitat by
CDWR after flow reductions revealed typical movement of spawning gravel in the lower
Feather River after a significant high-flow event,with some areas gaining and some
loosing gravel,typical of an alluvial system.
• Large woody debris,
o No adverse modifications to large wood have been identified as a result of response
actions.
• Riparian vegetation and shade resulting in increased stream bank erosion,
65
o As previously stated, some stream bank erosion is expected during normal high flows;
however,there is no indication that riparian vegetation was adversely modified from
the response actions taken.
• Nutrient inputs
o There is no indication that nutrient inputs were adversely modified from response
actions taken. It is likely that longer duration and higher spring flows actually increased
access to nutrients on floodplain habitats within the lower Feather River corridor and
beyond.
66
S CONSERVATION MEASURES TAKEN BY CDWR
On February 7, 2017, when signs of the FCO Spillway failure were observed, it became evident
that salmonids at the FRFH were at risk. An effort to protect the fish and the facilities that
support them was initiated and included the following:
• Movement of fish to the Thermalito Annex which relies on groundwater wells,
rather than river water;
• Creation of a sediment settling basin within the rearing channel to pumpclean,
settled water into the headboxes in the rearing channel;
• Development of alternative sources of water using a fire hydrant;
• Cleaning out of mud in the incubation stacks and inland ponds;
• Monitoring and maintaining turbidity and water quality levels;
• Use of supplemental medicated and probiotic feed to improve the health ofthe
fish;
• Additions of salt to prevent disease; and
• Cleaning of raceways.
Due to concerns over potential water quality impacts during the incident, the FRFH kept and
raised additional steelhead eggs and juveniles. Due to the highly effective nature of the actions
taken (described above), production numbers at the FRFH were significantly increased.
• The FRFH raised an additional 213,000 CCV Steelhead yearlings.
0 182,000 yearling CCV Steelhead were released into the Thermalito Afterbay in
January and early February for a put-and-take fishery. An unknown number of
these Steelhead will leave the Afterbay before being harvested and will enter the
lower Feather River. Some portion of these will contribute to the overall
population of Steelhead in the lower Feather River by returning as adults and
spawning at the FRFH and in the lower Feather River.
o An additional 31,000 yearling CCV Steelhead were released into the lower
Feather River in February as an enhancement to normal production releases.
o The FRFH released two million additional Fall-run Chinook Salmon juveniles in
2018, one million near San Pablo Bay and one million in the lower Sacramento
River. This is in addition to the normal production release of six million also
released in the spring and summer of 2018. This release will provide additional
angling opportunities in the both the ocean and inland fisheries and some fish
will escape to spawn at the FRFH and the lower Feather River.
67
On February 27, 2017, release rates from the Oroville Dam FCO Spillway were rapidly decreased
to accommodate the required (emergency) assessments and continued to decrease until
releases ceased over the FCO Spillway. Flows remained low for about one week in the LFC and
HFC, but never went below minimums for each channel. Dining this first rapid flow reduction
CDWR, CDFW, and NMFS mobilized significant personnel and resources to implement fish
rescues. The effort included flying the river on multiple days to identify stranding pools using
real-time mapping so crews could be deployed to over 50 miles of river daily to areas in most
need of rescue efforts. During the three other rapid flow reductions (March 27, May 1, and May
19, 2017), CDWR and CDFW continued to perform fish rescues based on data gathered during
the prior events. As rescue.efforts progressed through the season, fewer and fewer fish were
found in stranding pools.
In August 2017, CDWR completed the addition of 5,000 cy of salmonid spawning gravel in the
LFC and removed a gravel plug from Moe's Side Channel to excavate and reconnect the channel
to the Feather River to restore the channel to normal function.
Although most of the recommendations from NMFS were followed, CDWR was unable to
implement some of the NMFS recommendations because of the intense and immediate nature
of the dredging operations, and the need to reduce flows during daylight hours to create the
safest possible conditions for monitoring the spillway. Actions were taken to provide minimum
flows to the Feather River and to protect salmonids being reared at FRFH and FRFH Annex. A
large and challenging sampling effort was made to survey stranding pools and fish rescues were
performed. A draft report detailing the effort was submitted to NMFS, FERC, CDFW, and FEMA
on November 6, 2017. The final report was submitted to the same parties on December 1,
2017.
8.1 Additional Proposed Conservation Measure
In addition to the conservation measure completed and described above,the Department
recommends the following actions related to the Feather River Fish Hatchery:
• Marking and tagging Fall-run Chinook is an important piece to Chinook Salmon
management in the Central Valley and a critical component to CV Spring-run Chinook
management in the Feather River. The FRFH, through CDWR, produces 6 million Fall-
run Chinook Salmon smolts for mitigation each year. These fish are coded-wire-tagged
at a constant fractional rate of 25%to enable the recovery of adult salmon in the sport
and ocean fisheries,the river, and the FRFH. The funding for this program has been paid
for by both CDWR and CDFW the past several years. CDWR proposes to pay for this
program for the next two years (2019 and 2020) or until the Spring-run Hatchery and
Genetic Management Plan (SR HGMP)for the Feather River has been approved by
NMFS. This will allow for a consistent marking program to continue until a new marking
strategy is enacted through implementation of the Spring-run HGMP.
68
9 LITERATURE CITED
Allan,J. D., M. S. Wipfli,J. P. Caouette, A. Prussian, and J. Rodgers. 2003. Influence of
streamside vegetation on inputs of terrestrial invertebrates to salmonid food webs.
Canadian Journal of Fisheries and Aquatic Sciences 60(3): 309-320.
Allen, M. A., and T.J. Hassler. 1986. Species Profiles: Life histories and environmental
requirements of coast fishes and invertebrates (Pacific Southwest) -- Chinook Salmon. U.S.
Fish and Wildlife Service Biological Report 82 (11.49). U.S. Army Corps of Engineers,TR EL-
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