HomeMy WebLinkAboutChapter 12 - Water ResourcesChapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
1
CHAPTER 12: WATER RESOURCES
TABLE OF CONTENTS
12.1 WATER RESOURCES.......................................................................................................................................4
GEOGRAPHY ..............................................................................................................................................................4
SURFACE WATER.......................................................................................................................................................4
Key Surface Water Sources..................................................................................................................................5
Big Chico Creek................................................................................................................................................................7
Butte Creek.......................................................................................................................................................................7
Middle Fork of the Feather River......................................................................................................................................8
North Fork of the Feather River........................................................................................................................................8
South Fork of the Feather River........................................................................................................................................8
Sacramento River..............................................................................................................................................................8
Climate, Precipitation, and Flow Variability.......................................................................................................8
GROUNDWATER .......................................................................................................................................................13
Groundwater Geomorphology...........................................................................................................................15
Sacramento Valley..........................................................................................................................................................15
Mountain Areas...............................................................................................................................................................16
Groundwater Recharge......................................................................................................................................16
Sacramento Valley..........................................................................................................................................................16
Mountain Areas...............................................................................................................................................................17
Groundwater Levels and Movement ..................................................................................................................19
Seasonal and Yearly Changes in Groundwater Levels....................................................................................................19
Long-Term Groundwater Level Change.........................................................................................................................20
Groundwater Movement.................................................................................................................................................20
Groundwater Development................................................................................................................................22
Groundwater Monitoring...................................................................................................................................24
REGULATORY SETTING............................................................................................................................................24
Federal Regulations...........................................................................................................................................24
Safe Drinking Water Act.................................................................................................................................................25
Clean Water Act..............................................................................................................................................................25
Reclamation, Recycling, and Water Conservation Act...................................................................................................25
FERC Relicensing...........................................................................................................................................................25
State and Federal Wild and Scenic Rivers System..........................................................................................................25
State Regulations................................................................................................................................................25
Local Water Supply Reliability.......................................................................................................................................26
Proposition 218 ...............................................................................................................................................................26
Proposition 13.................................................................................................................................................................26
Dischargeable Allowances..............................................................................................................................................26
Enforcement of Wastewater Reclamation Criteria..........................................................................................................26
Groundwater...................................................................................................................................................................27
Regulations for Water Use Efficiency ............................................................................................................................27
Urban Water Management Planning Act ........................................................................................................................27
Agricultural Water Management Planning Act...............................................................................................................27
Area of Origin Protections..............................................................................................................................................27
Local Organizations and Regulations................................................................................................................27
Butte County Water Commission ...................................................................................................................................28
Butte County Department of Water and Resource Conservation....................................................................................28
Butte Basin Water Users Association .............................................................................................................................28
Butte County Groundwater Protection Ordinance (Chapter 33) .....................................................................................29
Butte County Well-Spacing Ordinance (Chapter 23B)...................................................................................................29
WATER RESOURCE PLANNING .................................................................................................................................30
Urban Water Management Plans (AB 797).......................................................................................................30
Agricultural Water Management Plans (AB 3616)............................................................................................30
Groundwater Planning ......................................................................................................................................31
Groundwater Management Plans (AB 3030)..................................................................................................................31
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Butte County General Plan Background Report
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EMERGING ISSUES ...................................................................................................................................................32
Northern – Southern California Water Resource Issues....................................................................................33
Emerging Groundwater Issues...........................................................................................................................33
Drought ...........................................................................................................................................................................33
Groundwater Development.............................................................................................................................................33
Statewide Trends.............................................................................................................................................................34
Water Resources Issues Advocacy Groups ........................................................................................................35
12.2 TREATMENT AND CONVEYANCE SYSTEMS.........................................................................................36
WATER PROVIDERS .................................................................................................................................................36
Biggs-West Gridley Water District ....................................................................................................................41
Durham Mutual Water Company.......................................................................................................................42
Richvale Irrigation District................................................................................................................................42
Thermalito Irrigation District............................................................................................................................42
California Water Service Company, Oroville....................................................................................................43
Western Canal Water District............................................................................................................................43
Del Oro Water Company ...................................................................................................................................44
Paradise Irrigation District...............................................................................................................................45
South Feather Water and Power Agency...........................................................................................................45
California Water Service Company, Chico........................................................................................................46
Dayton Mutual Water Company ........................................................................................................................47
Durham Irrigation District ................................................................................................................................47
STORAGE FACILITIES ...............................................................................................................................................47
Lake Oroville .....................................................................................................................................................47
Thermalito Forebay and Afterbay......................................................................................................................48
Paradise and Magalia Reservoirs......................................................................................................................48
Other Surface Water Storage Facilities.............................................................................................................48
REGULATORY SETTING............................................................................................................................................49
EMERGING ISSUES ...................................................................................................................................................50
12.3 WATER QUALITY ..........................................................................................................................................50
EXISTING CONDITIONS ............................................................................................................................................51
Water Quality in Public Supply Wells................................................................................................................51
REGULATORY BACKGROUND ..................................................................................................................................52
Federal Regulations...........................................................................................................................................52
Clean Water Act-National Pollutant Discharge Elimination System..............................................................................52
Safe Drinking Water Act.................................................................................................................................................52
State Regulations................................................................................................................................................53
Porter-Cologne Water Quality Control Act.....................................................................................................................53
California Safe Drinking Water Act................................................................................................................................53
EMERGING ISSUES ...................................................................................................................................................53
Pollutants of Concern ........................................................................................................................................54
Future Water Quality Measures.........................................................................................................................54
Source Water Quality......................................................................................................................................................55
Agricultural Irrigation.....................................................................................................................................................55
12.4 EXISTING SUPPLY AND DEMAND.............................................................................................................55
HISTORIC WATER DEVELOPMENT ...........................................................................................................................55
EXISTING DEMAND ..................................................................................................................................................56
EXISTING SUPPLY ....................................................................................................................................................59
Drought Year Demand versus Supply................................................................................................................60
Urban.................................................................................................................................................................60
Agricultural........................................................................................................................................................61
Environmental....................................................................................................................................................61
12.5 FUTURE WATER SUPPLY AND DEMAND................................................................................................61
FUTURE WATER DEMAND BY USE ...........................................................................................................................61
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Final Draft August 8, 2005
Butte County General Plan Background Report
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WATER CONSERVATION POTENTIAL .......................................................................................................................62
Water Recycling.................................................................................................................................................63
Water Pricing.....................................................................................................................................................63
LIST OF TABLES
TABLE 12-1 SURFACE WATER RESOURCES ....................................................................................................................7
TABLE 12-2 ANNUAL PRECIPITATION AND SNOWFALL AT FOUR STATIONS (INCHES)....................................................9
TABLE 12-3 COUNTY SURFACE WATER INFLOWS IN CUBIC FEET PER SECOND (CFS)..................................................11
TABLE 12-4 BUTTE COUNTY SUB-BASIN CHARACTERISTICS .......................................................................................22
TABLE 12-5 NUMBER OF WELLS BY INVENTORY UNIT AND INVENTORY SUB-UNIT....................................................22
TABLE 12-6 ADVOCACY GROUPS .................................................................................................................................35
TABLE 12-7 PLANNED WATER SYSTEM IMPROVEMENTS .............................................................................................39
TABLE 12-8 WATER SYSTEMS SUMMARY ....................................................................................................................40
TABLE 12-9 DIVISION OF DAM SAFETY JURISDICTION BUTTE COUNTY DAMS ............................................................49
TABLE 12-10 BUTTE COUNTY SUB-BASIN WATER QUALITY .......................................................................................52
TABLE 12-11 INVENTORY UNITS AND WATER SUPPLIERS............................................................................................56
TABLE 12-12 NORMAL YEAR WATER DEMAND (IN THOUSANDS OF ACRE-FEET).........................................................59
TABLE 12-13 NORMAL YEAR SUPPLIES (IN THOUSANDS OF ACRE-FEET)......................................................................59
TABLE 12-14 WATER SHORTAGES AND DEMAND DURING DROUGHT YEAR ................................................................60
TABLE 12-15 POPULATION PER INVENTORY UNIT........................................................................................................61
LIST OF FIGURES
FIGURE 12-1: SURFACE WATER .....................................................................................................................................6
FIGURE 12-2: COUNTY ISOHYETAL MAP ......................................................................................................................10
FIGURE 12-3 AVERAGE ANNUAL PRECIPITATION IN WINTER AND SUMMER, BUTTE COUNTY WEATHER STATIONS ...11
FIGURE 12-4 SACRAMENTO RIVER WATER SUPPLY INDEX ..........................................................................................13
FIGURE 12-5 GROUNDWATER SUBBASINS ....................................................................................................................14
FIGURE 12-6 GROUNDWATER RECHARGE AREAS ........................................................................................................18
FIGURE 12-7 GROUNDWATER ELEVATION AND MOVEMENT ........................................................................................21
FIGURE 12-8 WELL LOCATIONS ...................................................................................................................................23
FIGURE 12-9: WATER PROVIDERS ................................................................................................................................38
FIGURE 12-10 INVENTORY UNITS.................................................................................................................................58
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Final Draft August 8, 2005
Butte County General Plan Background Report
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12.1 WATER RESOURCES
Water is one of Butte County’s most important natural resources. It has always been viewed as
an abundant resource that reflects the county’s location in a northern California region where
annual precipitation is relatively high. The county is viewed by some as a potential source of
additional water that could be exported to other areas of the state. At the same time, water
available for residential, commercial, agricultural, and environmental use may be diminishing in
some parts of the county.
In order to appropriately assess supply and plan for future needs, water (both surface and
groundwater) should be seen as an interconnected system, with activities in any part of the
system affecting water supply and water quality in the entire system. The following section
addresses water resources in the county, whereas later sections assess the use, storage, quality,
and future availability of these resources.’
Geography
Butte County is located in the Sacramento River Hydrological Region, which covers
approximately 17 million acres (27,000 square miles).1 In addition to Butte, the region includes
all or large portions of Modoc, Siskiyou, Lassen, Shasta, Tehama, Glenn, Plumas, Colusa, Sutter,
Yuba, Sierra, Nevada, Placer, Sacramento, El Dorado, Yolo, Solano, Lake, and Napa counties.
The region extends south from the Modoc Plateau and Cascade Range at the Oregon border to
the Sacramento-San Joaquin Delta. Significant features include the Sacramento River, which is
the longest river system in the state of California. Its major tributaries are the Pit, Feather, Yuba,
Bear and American rivers.
The Sacramento River Hydrological Region is the main water supply for much of California’s
urban and agricultural areas. Annual runoff in the region averages about 22.4 million acre-feet
(MAF), which is nearly one-third of the state’s total natural runoff. Major water supplies in the
region are provided through surface storage reservoirs. The two largest surface water projects in
the region are U.S. Bureau of Reclamation’s Shasta Lake/Dam (Central Valley Project) on the
upper Sacramento River and Lake Oroville (California Department of Water Resources’ State
Water Project) on the Feather River. Municipal, industrial, and agricultural supplies to the region
are about 8 MAF, with groundwater providing about 2.5 MAF of that total. Much of the
remainder of the total runoff goes to dedicated natural flows that support various environmental
requirements, including in-stream fishery flows and flushing flows in the Delta.2
Surface Water
The majority of the surface water supply used by Butte County residents and businesses
originates in the Feather River watershed, accumulates in Lake Oroville, and is used for
agriculture. The entire county lies within the Sacramento River watershed. The Feather River
1 California Department of Water Resources. Draft State Water Plan Update. 2003
2 California Department of Water Resources. Draft State Water Plan Update. 2003
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Butte County General Plan Background Report
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with its several branches flows through the county. Butte Creek and Big Chico Creek are primary
county waterways (Figure 12-1).
Key Surface Water Sources
Key characteristics of the county’s primary waterways are described in the table and text that
follow (Table 12-1).
Butte County
General Plan
Figure 12-1
SURFACE WATER
Source: Camp Dresser & McKee, 2001.
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Final Draft August 8, 2005
Butte County General Plan Background Report
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TABLE 12-1
SURFACE WATER RESOURCES
Name Location Current Use/Potential for Use
Big Chico Creek North of Chico Recreation, important wildlife habitat
Butte Creek Butte Meadows to southwest county
boundary
Irrigation, stock watering, recreation, important
wildlife habitat
Middle Fork Feather
River
East of Oroville Power, recreation, important wildlife habitat
North Fork Feather
River
Northeast of Oroville Power, recreation, important wildlife habitat, fisheries
Sacramento River Western boundary of county Irrigation, stock watering, important wildlife habitat,
recreation
Thermalito Forebay Oroville Recreation, power, irrigation, important wildlife
habitat
Thermalito Afterbay Oroville Irrigation, important wildlife habitat, recreation
Little Butte Creek Northeastern portion of county Water supply, wildlife habitat
Little Chico Creek Northeast of Chico Water supply, important wildlife habitat
Rock Creek Northwest of Chico N/A
Dry Creek/Cherokee
Canal
Near Paradise to southwestern portion of
county
Water supply
Source: Michael Clayton and Associates, 1991; adapted by Cotton/Bridges/Associates, 2003.
Big Chico Creek
Big Chico Creek flows from the northern portion of the county through Bidwell Park in the city
of Chico, and eventually into the Sacramento River near River Road.
Big Chico Creek experienced severe declines in salmon and steelhead trout from historic levels.
A stream survey conducted by the California Department of Fish and Game (DFG) in 1989
estimated that only a remnant spring-run salmon population existed in Big Chico Creek, along
with a depressed steelhead run and a highly variable spawning population of fall run salmon. A
special study done by DFG in 1989 found the decline was largely due to agricultural pumping at
the confluence of Big Chico Creek and the Sacramento River. This problem was addressed in
1993 with the formation a subcommittee of the City of Chico Parks Commission, which was
called the Big Chico Creek Task Force (BCCTF). The BCCTF was successful in relocation of
the pumps and the construction of a bypass to prevent release of silt from the One-Mile pool
during cleanings and the installation of a new stream gauge on Big Chico Creek at the golf
course. These actions have significantly improved the stream, as demonstrated by the increase of
the spring run salmon from a remnant population to more than 350 counted in September 1998.
Butte Creek
Butte Creek originates in the hills of Butte Meadows and flows through the southern portion of
the cities of Chico and Durham to form the county border from Nelson Road south. This creek is
used mostly for recreation and fishing in the upper reaches near Butte Meadows and in Chico
and Durham. Southern portions of the creek provide stock watering and irrigation. The upper
reaches of Butte Creek are characterized by excellent flow, temperature, and habitat conditions
for salmon. In the past, diversion dams in lower Butte Creek have presented problems to fish
migration and these impacted spawning grounds. However, a major diversion dam was removed,
and other improvements have been made that improve the ability of salmon to migrate. Though
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Final Draft August 8, 2005
Butte County General Plan Background Report
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salmon populations have decreased substantially in the past 30 years, their numbers have been
rebounding due to these improvements and a series of wet winters.
Middle Fork of the Feather River
The Middle Fork of the Feather River is located east of Oroville and enters Lake Oroville north
of Feather Falls. Within Butte County, a 10.5-mile stretch of this river has been designated as a
National Wild and Scenic River. Although the steep canyons forming the river walls make
access difficult, the river is host to various recreational activities and provides rich wildlife
habitat.
North Fork of the Feather River
The North Fork of the Feather River flows southwest out of the Sierra Nevada into Lake
Oroville. The river supports various recreational activities and a rich wildlife habitat. It has
excellent conditions for hydroelectric power generation and hosts nine hydroelectric facilities.
Four additional hydroelectric facilities are proposed for tributaries.
South Fork of the Feather River
The South Fork of the Feather River is located east of Oroville and enters Lake Oroville at the
Ponderosa Reservoir. The South Fork flows southwest/west out of the Sierra Nevada. The river
provides a rich wildlife habitat supporting a variety of animal and plant species.
Sacramento River
The Sacramento River forms the western boundary of the county. The river supports various
recreational activities, agricultural irrigation, stock watering, and diverse wildlife habitats,
including habitat for Special Status Species (federal and State threatened and endangered
species). The river has carved out wide flood plains outside both banks. In an effort to contain
the river’s floodwater, levees have been built up around a large portion of its banks. The
California Department of Water Resources, Division of Flood Management established the
Sacramento River Flood Control Project to implement flood control projects for the entire
Sacramento River system, including its tributaries. The two components of this project within
Butte County are the Chico Landing to Red Bluff Project and the Sacramento River Bank
Protection Program.
Climate, Precipitation, and Flow Variability
Surface water flows in Butte County are, as for the Sacramento basin as a whole, extremely
variable, both seasonally and annually. Their partial dependence on annual snow melt tends to
mitigate the seasonal variability. Butte County includes geographic provinces of the Sacramento
Valley, and the foothill and mountain areas of the Sierra and Cascade ranges. The mountainous
portions of the county comprise approximately a third of the county’s land area and function as
the major watershed area, though the foothill areas also collect considerable precipitation.
Higher-altitude portions of the county receive abundant snowfall. Most of the annual
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Butte County General Plan Background Report
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precipitation occurs during the winter and spring. Conversely, the highest water usage is during
the hot, dry summer months when agricultural irrigation is in progress.
Precipitation in different portions of the county ranges from less than 20 inches annual rainfall in
the western valley area to over 80 inches in the eastern Cascades and Sierra Nevada mountains.
There is a strong orographic effect observed relative to precipitation between the low elevation
valley areas and the eastern mountains. Moisture-laden weather patterns from the Pacific Ocean
move east during the winter months. Orographic cooling occurs as the moving air mass is forced
upward over the Sierra Nevada, resulting in condensation of moisture and precipitation. Up to
4,000 feet above sea level, most of the precipitation that falls does so as rain. Above 4,000 feet, a
considerable portion of winter precipitation occurs as snow. This variation in precipitation is
shown in Figure 12-2, which is an isohyetal map for the county.
Measurements taken at four county weather stations have been selected to illustrate the seasonal
variation in precipitation and variation in rainfall and snowfall over different elevations. Table
12-2 shows minimums, averages, and maximums of annual precipitation and snowfall.
TABLE 12-2
ANNUAL PRECIPITATION AND SNOWFALL AT FOUR STATIONS (INCHES)
Chico University Farm Oroville Paradise De Sabla
Elevation (in feet above mean sea level)185 171 1,750 2,710
Precipitation
Average 25 30 54 66
Maximum 46 60 100 121
Minimum 10 14 18 22
Snowfall
Average 0.12 0.04 3.0 26
Maximum 4.3 1.3 32 140
Minimum 0 0 0 0
Source: Camp Dresser & McKee. 2001.
Butte County
General Plan
Figure 12-2
COUNTY ISOHYETAL MAP
Source: Camp Dresser & McKee, 2001.
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
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Precipitation is strongly seasonal, with about half of the total annual precipitation generally
occurring from November through mid-February (Figure 12-3).
Figure 12-3
Average Annual Precipitation in Winter and Summer, Butte County Weather Stations
21.33
7.78
55.98
46.92
24.56
3.83 4.03
9.71
0
10
20
30
40
50
60
Chico
University
Farm
Oroville Paradise De Sabla
(in
ch
es)
Winter
Summer
Table 12-3 shows a summary of monthly flow data at two streamflow measurement sites in the
county. As shown, both measurement sites demonstrate a wide variability in flow. For Big Chico
Creek the maximum flow month was 10 times higher than the mean flow rate. For Butte Creek,
maximum flow month was seven times higher than the mean flow rate, and the mean was nine
times higher than the minimum flow month. The highest monthly flows occur between January
and April while the minimum flows occur between July and September.
TABLE 12-3
COUNTY SURFACE WATER INFLOWS IN CUBIC FEET PER SECOND (CFS)
Month Big Chico Creek near Chico Butte Creek near Chico
January 165 347
February 197 416
March 164 389
April 111 343
May 45 254
June 22 145
July 14 84
August 12 67
September 12 60
October 18 70
November 42 114
December 109 228
Mean Monthly cfs 76 209
Maximum Monthly cfs 760 1474
Minimum Monthly cfs 7 23
Source: Camp Dresser & McKee. 2001.
In addition to the seasonal variability, surface water flow is highly variable on a year-to-year
basis. A good indicator of annual surface flow variability in the region is the Sacramento River
Water Supply Index. Based on the calculated runoff in million acre-feet, each year of the index is
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
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then classified as wet, above normal, below normal, dry or critical. Figure 12-4 shows the
Sacramento River Water Supply Index annually since 1906 and the classification range for each
type year. As is shown, the annual variability for the northern Sacramento Valley is quite
pronounced, with wet years, dry years and critically dry years occurring frequently. This
seasonal, yearly, and orographic variability creates the need for an extensive system of water
storage and delivery, as well as well-developed water management techniques.
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
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Figure 12-4
Sacramento River Water Supply Index
Source: California Department of Water Resources, 2000.
Groundwater
A majority of residential water supply in incorporated portions of the county is extracted from
groundwater basins. The availability of groundwater in an area depends largely upon its
geologic, hydrologic, and climatic conditions. In Butte County, reserves of groundwater are
found in the thick sedimentary deposits of the Sacramento Valley. Groundwater can also be
found in more limited amounts in mountainous areas of the county within volcanic,
metamorphic, and granitic rocks. The Butte Basin is the primary groundwater basin in the
county, and portions of it underlay adjoining counties. Sub-basins located in Butte County
include East Butte, West Butte, Vina, and North Yuba (Figure 12-5). Characteristics of
groundwater in the county are described below specific to these sub-basins.
#
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Virginia
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Chico
Vina
Sub-basin
East Butte
Sub-basin
North Yorba
Sub-basin
Groundwater Basins and Subbasins
County Boundaries
Lakes/Reservoirs/Bays
Roads/Rivers/Creeks
Legend
Figure 12-5
GROUNDWATER SUBBASINS
Butte County
General Plan
Source: California Department of Water Resources, 2003.
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
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Groundwater is stored in the pore spaces between particles of granular soil and rock materials,
and in the joints and fractures of consolidated rocks. In coarse-grained material, such as sand and
gravel, pores are more interconnected than those of clay or silt, facilitating the free movement of
water. Fine-grained materials, such as clay and silt deposits, impede groundwater movement and
do not readily yield water. Consolidated rocks provide storage space in their joint and fracture
systems which allow for groundwater movement and water yield. Only where wells directly
intercept major joints or fractures do these aquifers provide dependable water sources.
Groundwater Geomorphology
Butte County is composed of three primary geomorphic provinces in two categories: the
mountain provinces (consisting of the Cascade and Sierra Nevada Geomorphic Provinces) and
the great valley province (consisting of four subareas). The four great valley province subareas
are:
• Dissected alluvial uplands;
• Low alluvial plains and fans;
• Floodplain and natural levees; and
• Flood basins
Butte County has two primary groundwater resource areas: the groundwater-rich Sacramento
Valley aquifer and the mountainous areas to the east and north, which have restricted
groundwater resources. The following paragraphs describe these groundwater resource areas.
Sacramento Valley
Relative amounts of coarse-grained and fine-grained material in the alluvial deposits of the
Sacramento Valley vary greatly in both the vertical and horizontal extent. However, clay and
fine-grained deposits far exceed those of coarse-grained materials. Coarser materials are
deposited in foothill areas. Finer materials are transported further into the valley and are more
gradually deposited.
Groundwater is found in perched, unconfined, and confined zones in the valley portion of Butte
County. Perched groundwater zones are most common in shallow, consolidated soils with low
permeability. Major portions of groundwater are unconfined or semi-confined, occurring in the
flood plain and alluvial fan deposits. High permeability in these soils yields large amounts of
water to shallow domestic and irrigation wells. Well-sorted coarse sand and gravel of the Older
Alluvium and Recent Stream Alluvium are highly permeable and yield large amounts of water to
domestic and irrigation wells.
The Tuscan Formation contains an important deep aquifer that underlies most of the valley area.
Confined water occurs in the Tuscan and Laguna Formations, and in the younger alluvium,
where it is overlain by flood-basin deposits. Although moderate amounts of water are yielded
from the fine-grained strata of the Laguna Formation, permeable sand and gravel zones are
infrequent and minor in extent and thickness. The highest-producing wells in alluvial uplands
occur when Older Alluvium or the deeper Tuscan volcanic rocks are tapped.
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Butte County General Plan Background Report
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Mountain Areas
The pre-Cretaceous rocks of the Sierra Nevada basement complex are consolidated, and
therefore exhibit low permeability. The groundwater contained in these rocks exists only in the
soil mantle, highly weathered zones, or openings formed by fractures, joints, and faults. In the
ridge areas, the Cretaceous age Chico Formation contains fresh groundwater. The original
(connate) saline or brackish water has been flushed out and replaced by potable groundwater,
and deep wells on the ridges or in the canyons can tap this source. Weathered and open fractured
rock can extend to several hundred feet deep. Shallow wells in perched zones typically yield only
a few gallons per minute and can go dry during drought years.
Volcanic capped ridge areas having intervolcanic sand and gravel deposits and aquiferous
gravels produce the most productive wells. Groundwater also occurs to a lesser extent in the soil
mantle and weathered surface developed on the Tuscan rocks. Water in the surface zone is
perched due to the impervious nature of the volcanic rocks. Perched groundwater is
discontinuous from the water table, a discrete saturated zone that may be ephemeral (in direct
response to precipitation in the immediate vicinity) or recharged by percolation from nearby
surface water or other perched water zones. Perched groundwater may be a source of potable
groundwater. The perched condition in areas with volcanic rock results in water flowing down
slope parallel to the ground surface and emerging in seeps along the canyon walls. The deeper
groundwater flows westward toward the Sacramento Valley and recharges the Tuscan
sedimentary rocks beneath the younger valley deposits.
Groundwater Recharge
The major sources of groundwater recharge in Butte County are percolation of rainfall,
infiltration from streams, subsurface inflow, and deep percolation of applied irrigation water in
agricultural areas. Of the 3.77 million acre-feet of annual rainfall, less than half is used.
Therefore, more than two million acre-feet are available for recharge or discharge via surface
and subsurface outflow. Groundwater recharge areas are shown in Figure 12-6, which identifies
the areas of permeability greater than two feet per day and the service agencies within that area
as detailed by the California Department of Water Resources (DWR). As shown, groundwater
recharge areas are located in the areas surrounding Chico and along the Sacramento River, as
well as in the southern portion of the county along the Feather River.
Sacramento Valley
Deep percolation of streamflow infiltration and precipitation are major sources of groundwater
recharge in the valley. Most of this recharge occurs on alluvial fans where streams have
sustained flow and the soil is highly permeable. In areas with clay soils or buried hardpan layers,
high rates of surface runoff and ponding of water indicate locations where infiltration rates are
low. Infiltration of surface runoff does occur at the basin margin where Tuscan and fanglomerate
rocks are overlain by valley deposits. Deep subsurface inflow occurs in mountainous areas,
flowing west to recharge the adjacent valley area.
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Mountain Areas
Subsurface inflow from higher elevations and percolation of precipitation are the major sources
of groundwater recharge in the mountain areas. Some recharge probably occurs adjacent to
through-flowing streams in areas of deeper soils or alluvial deposits.
No Scale.
Figure 12-6
GROUNDWATER
RECHARGE AREAS
Butte County
General Plan
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19
Groundwater Levels and Movement
Throughout a large portion of Butte County fresh water reportedly extends to a depth of 1,150
feet below sea level, or 800 to 1,350 feet below the ground surface, though groundwater levels
can change due to extraction and natural processes.3 Spring groundwater levels vary from an
elevation of about 60 feet in the Butte Sink sub-basin, to about 170 feet above mean sea level
(msl) in the northeastern part of the Vina sub-basin (Figure 12-7).
Seasonal and Yearly Changes in Groundwater Levels
Change in groundwater storage is most basically dependent upon the annual rate of groundwater
extraction and the annual rate of groundwater recharge, commonly fluctuating within a given
year and from year to year. During periods of drought, groundwater in storage typically declines,
but increases during periods of above normal precipitation. Groundwater in storage declines
during the summer as groundwater is extracted for municipal and agricultural use, and recovers
as extraction slows and seasonal precipitation increases recharge.
The annual spring-to-spring change in groundwater in storage for the Sacramento Valley portion
of Butte County was calculated over a 20-year period from 1980 to 2000, including a period of
drought between approximately 1988 and 1994. There was slightly more groundwater in storage
in 1987 than in 1980, and subsequently less groundwater in storage during the drought (1988-
1994). Importantly, there was a rapid recovery of approximately 100,000 acre-feet in the first
year following the drought to a volume exceeding that in storage immediately prior to the
drought, showing that the aquifer is responsive when an adequate volume of recharge is
available.
Seasonal fluctuation of groundwater levels in the unconfined portion of the aquifer system
averages between three to five feet during years of normal precipitation, and seven to nine feet
during periods of drought. The annual fluctuation of groundwater levels in the confined or semi-
confined portion of the aquifer system averages about 10 feet during periods of normal
precipitation and about 20 feet during times of drought. Wells constructed in unconfined parts of
the aquifer system tend to show less seasonal fluctuation in groundwater level than those in the
lower, confined aquifer system because of the greater interconnection between the shallow
groundwater and the surface-water systems. The areas of greatest groundwater level decline are
those where groundwater is extracted for agricultural and/or municipal use during the summer
months in the Vina and North Yuba groundwater sub-basins, the Durham area of the West Butte
sub-basin, and the Cherokee Strip portion of the East Butte sub-basin. Hydrographs indicate that
groundwater typically recharges during the winter months.
Groundwater hydrographs for monitoring wells near Chico indicate a rather uniform seasonal
fluctuation of 15 to 20 feet during normal years. During drought years, there tends to be a wider
range of fluctuation depending upon the individual well. Wells in the southern portion of the
county show less seasonal fluctuation than those in the northern county largely because of
recharge of the upper aquifer system from applied surface-water and limited agricultural use of
groundwater from the middle and lower aquifer system in the southern area.
3 Camp Dresser & McKee. Water Inventory and Analysis Report. 2001.
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Long-Term Groundwater Level Change
The amount of groundwater in storage during the spring of 2000 was about 15,000 acre-feet
greater than that of 1980. Review of the hydrographs for long-term comparison of spring-to-
spring groundwater levels indicates a decline in groundwater levels associated with the 1976-77
and 1986-94 droughts, followed by a recovery in groundwater levels to pre-drought conditions of
the early 1970s and 1980s. Valley-wide comparison indicates that there has been very little
change in groundwater levels in most areas of the valley since the 1970s and 1980s. However,
further long-term comparison of spring-to-spring groundwater levels from the 1950s and 1960s
with today’s levels indicates a trend of slightly declining groundwater levels in some areas of the
West Butte and Vina sub-basins.
Groundwater Movement
The overall pattern of groundwater movement during spring is southwesterly toward the
Sacramento River, although locally the movement of groundwater varies (Figure 12-7). There
are groundwater mounds just south of the Thermalito Afterbay and just west of Hamilton City,
associated with the Stony Creek Fan, suggesting recharge from the Afterbay and from deep
percolation of surface water. There are isolated areas of groundwater depression located under
the city of Chico resulting from year-around pumping of groundwater for municipal use. A more
widespread depression is located in the southwest portion of the North Yuba Inventory Unit.
Source: Camp Dresser & McKee, 2001.
Figure 12-7
GROUNDWATER ELEVATION AND MOVEMENTS
Butte County
General Plan
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Groundwater Development
Groundwater provides about 30 percent of the water supply for urban and agricultural uses in the
Sacramento Hydrologic Region, and has been developed in both the alluvial basins and the hard
rock uplands and mountains. Groundwater use is not governed by the State Water Resources
Control Board (SWRCB), which is the agency set up to regulate surface water rights. There is no
system of groundwater rights except in adjudicated basins; therefore people do not need to apply
for rights before groundwater can be used.
In general, well yields are good and range from a hundred to several thousand gallons per
minute. In the mountain valleys and basins with arable land, groundwater supplements surface
water supplies. Some rural mountain areas of the region are entirely reliant on groundwater for
domestic supplies. However, the Paradise area is supplied principally from surface water
sources. Table 12-4 illustrates the quantities of groundwater pumpage by sub-basin.
TABLE 12-4
BUTTE COUNTY SUB-BASIN CHARACTERISTICS
Well YieldNameSub-basin Number Area (in acres)Maximum Average
Vina 5-21.57 124,700 3,850 1,212
West Butte 5-21.58 181,600 4,000 1,833
East Butte 5-21.59 265,000 4,500 1,019
North Yuba 5-21.60 100,400 4,000 840*
Note: * The average well yield for North Yuba is from the Camp Dresser McKee Water Inventory and Analysis, 2001.
Source: California Department of Water Resources. Groundwater Update, 2003.
There are over 14,000 wells in Butte County.4 Table 12-5 shows the numbers of wells by type,
inventory unit, and inventory sub-unit throughout the county. Figure 12-8 illustrates well
locations throughout the county.
TABLE 12-5
NUMBER OF WELLS BY INVENTORY UNIT AND INVENTORY SUB-UNIT
Inventory
Unit
Domestic
Wells
Irrigation
Wells
Municipal
Wells
Monitoring
Wells
Other
Wells Totals
Vina 2,096 621 55 138 299 3,209
West Butte 1,237 701 40 257 340 2,575
East Butte 1,647 699 12 71 287 2,717
North Yuba 504 178 8 95 81 866
Foothill 2,604 86 28 54 107 2,879
Mountain 1,954 11 20 13 29 2,027
TOTAL COUNTY:10,042 2,296 163 628 1,143 14,272
Note: Municipal includes wells classified as Municipal and Public.
Source: Camp Dresser & McKee, 2001; based on DWR data.
4 Ibid.
Butte County
General Plan
Figure 12-8
WELL LOCATIONS
No Scale.
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Groundwater Monitoring
Groundwater level monitoring in the Sacramento Valley portion of Butte County is conducted by
a number of different private and public agencies, though historically, the DWR has maintained
the most comprehensive, long-term groundwater level monitoring grid. Since 1997, Butte
County and DWR have coordinated water level monitoring efforts.
As part of the implementation of the Groundwater Protection Ordinance (Chapter 33 of the Butte
County Code), the County is required to establish a well-monitoring grid to facilitate a greater
understanding of the sub-surface aquifer. Data gathered from these wells will provide
information to better enable the County to identify and prevent third-party impacts associated
with a water transfer permit.
In order to determine what type of monitoring was already in place, in August 1997 Butte
County staff drafted and distributed a survey regarding the well monitoring activities that were
already taking place within the county to identify where there might be gaps in the data.
Suggested locations for additional water level monitoring were developed. Areas of potential
subsidence were plotted based on known subsurface geologic properties. Recommendations for
locating extensometers, which are devices capable of measuring land subsidence, were also
developed by the County.
Using these recommendations, over 30 well monitoring sites have been added to the grid, as well
as 3 extensometers in potential land subsidence areas. Two more extensometers are scheduled to
be added in the summer of 2003. The county now has a total of 50 monitoring sites. The County
is encouraging agricultural irrigation districts supplied by surface water to be involved in the
monitoring program. The Richvale Irrigation District approved the purchase of a continuous
recorder to install on a well within their district. The County is coordinating with representatives
of Western Canal Water District, which has independently conducted water level monitoring
since the summer of 1994.
Regulatory Setting
Surface water quality in Butte County is managed by local agencies in accordance with State
standards. The County has instituted a set of local standards in specific watershed areas: policies
and standards for the Firhaven Creek; Paradise Reservoir; and, Magalia Reservoir Watersheds.
The County relies on State water quality standards for dischargeable allowances, wastewater
reclamation, and drinking water. Jurisdiction relating to permits, citations, and monitoring or
surveillance programs required for water quality control is managed by a combination of state
and local agencies.
Federal Regulations
The Bureau of Reclamation operates the Central Valley Project, the largest water project in
California. The United State Environmental Protection Agency (U.S. EPA), Fish and Wildlife
Service, and others play important roles in the management of California’s water resources. The
federal government is responsible to represent the public trust values. The federal government
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provides assistance and guidance to local governments, Native American Tribes, and special
districts through legislation, as discussed below.
Safe Drinking Water Act
The Safe Drinking Water Act (SDWA), passed in 1974, is the initial federal legislation passed to
ensure the quality of drinking water.
Clean Water Act
The Clean Water Act (CWA) is a 1977 amendment to the Federal Water Pollution Control Act of
1972 which set up the basic structure for regulating discharges of pollutants to waters of the
United States. Both point and nonpoint source discharges to surface water are regulated by the
CWA. Additionally, wetland protection is addressed under the CWA. Section 404 of the federal
Clean Water Act regulates the discharge of dredged and fill materials into waters of the United
States, including wetlands.
Reclamation, Recycling, and Water Conservation Act
The Reclamation, Recycling, and Water Conservation Act authorized 25 percent federal cost-
sharing for higher level wastewater treatment plants.
FERC Relicensing
The Federal Energy Regulatory Commission (FERC) licenses all non-federal hydroelectric
plants. The Federal Power Commission (FPC), FERC’s predecessor, licensed the Oroville
facilities on February 11, 1957, for a period of 50 years. The Oroville facilities are scheduled to
be relicensed in 2007. A FERC license establishes operational parameters for the facility,
including conditions such as instream flow requirements and fishery protection measures.
State and Federal Wild and Scenic Rivers System
In 1968, Congress passed the National Wild and Scenic Rivers Act to preserve, in their free
flowing condition, rivers that possess “outstandingly remarkable scenic, recreational, geologic,
fish and wildlife, historic, cultural, or other similar values.”
State Regulations
In 1967, the State Water Rights Board and the State Water Quality Control Board were merged
to create the State Water Resources Control Board (SWRCB), integrating water rights and water
quality decision-making authority. The SWRCB is also solely responsible for allocating surface
water rights. Five full-time Board members, appointed by the Governor, are responsible for
setting statewide water policy. The nine Regional Water Quality Control Boards (RWQCB) are
responsible for protecting the surface, ground and coastal waters of their regions. The
Department of Fish and Game, the Department of Health Services, California Environmental
Protection Agency (CEPA), Department of Food and Agriculture, and others play important
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roles in the management of California’s water resources. Following is a summary of key
legislation affecting water supply in California.
Local Water Supply Reliability
Statutes of 1995, Chapters 330 and 854 require local water agencies to assess the reliability of
their water supplies. Statutes of 1995, Chapter 881 require consultation with local water agencies
to determine if an adequate water supply is available to accommodate pending land use planning
decisions.
Proposition 218
Proposition 218 requires a local vote to increase any fees that are an “incident of property
ownership,” water-related fees, such as meter charges, acreage-based irrigation charges, or
standby charges. Some subsequent court decisions provide further guidance for public agencies
(e.g., Howard Jarvis Taxpayers Association v. City of Roseville).
Proposition 13
The 2000 Water Bond (the Safe Drinking Water, Clean Water, Watershed Protection and Flood
Protection Act) authorized $1.97 billion for water projects.
Dischargeable Allowances
Criteria for dischargeable allowances into surface waters in Butte County have been developed
by the State Water Quality Control Board, Division of Water Quality. These requirements are
used as criteria in granting National Pollutant Discharge Elimination System (NPDES) permits,
which are obtained through the Regional Water Quality Control Board (RWQCB). Any facility
or activity that will discharge waste into any surface water, or from which waste may be
discharged in a diffused manner, must obtain waste discharge requirements which serve as a
federal NPDES permit. If waste will be discharged into surface waters from an enclosed system,
such as a pipe or confined channel, a NPDES permit is required instead of waste discharge
requirements. Most facilities discharging waste into public sewer systems are not required to
obtain a NPDES permit, however the Environmental Protection Agency may require some
industries to treat hazardous wastes prior to discharge into a public sewer system. The Butte
County Environmental Health Department advises industries of these requirements.
The RWQCB evaluates NPDES permit applications to determine whether the proposed
discharge is consistent with the adopted water quality objectives, the area-wide Waste Treatment
Management (“208”) Plan, the Region 5 Basin Plan, and the federal effluent limitations.
Enforcement of Wastewater Reclamation Criteria
Enforcement of Title 22 of the California Code of Standards is a responsibility of the Regional
Water Quality Control Board and the California Department of Health Services. The criteria
established by the State are locally enforced by the Butte County Health Officer. In
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circumstances dealing with mining site reclamation, the California Division of Mines and
Geology plays an active role.
Groundwater
Criteria for dischargeable allowances into groundwater basins in Butte County have been
developed by the California Water Quality Control Board, Division of Water Quality. These
requirements are used as criteria in granting NPDES permits. Any facility or activity that will
discharge waste that may affect groundwater quality must obtain waste discharge requirements
which serve as a federal NPDES permit. The Regional Water Quality Control Board evaluates
NPDES permit applications to determine whether the proposed discharge is consistent with the
adopted water quality objectives, the area-wide Waste Treatment Management (“208”) Plan, the
Basin Plan for Butte County, and the federal effluent limitations.
Regulations for Water Use Efficiency
The California Constitution prohibits the waste, unreasonable use, unreasonable method of use,
or unreasonable method of diversion of water.5 It also declares that the conservation and use of
water “shall be exercised with a view to the reasonable and beneficial use thereof in the public
interest and for the public welfare.” Water Code Section 275 directs the Department and
SWRCB to “take all appropriate proceedings or actions before executive, legislative, or judicial
agencies to prevent waste or unreasonable use of water.”
Urban Water Management Planning Act
Since 1983, this act has required urban water suppliers that serve more than 3,000 customers or
more than 3,000 acre-feet per year to prepare and adopt urban water conservation plans.
Agricultural Water Management Planning Act
Under this act, agricultural water suppliers supplying more than 50,000 acre-feet of water
annually are required to submit a report to DWR indicating whether a significant opportunity
exists to conserve water or reduce the quantity of highly saline or toxic drainage water through
improved irrigation water management.
Area of Origin Protections
Area of origin provisions were added to the Water Code to protect local northern California
supplies from being depleted by water projects. County of origin statutes reserve water supplies
for counties from which the water originates when, in the judgment of the State Water Resources
Control Board, an application for the assignment or release from priority of State water right
filings will deprive the county of water necessary for its present and future development.
Local Organizations and Regulations
5 California Department of Water Resources. Draft State Water Plan Update. 2003.
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Butte County Water Commission
The Water Commission meets regularly to discuss water issues of the county and provide
recommendations to the Board of Supervisors for actions related to water resources. The
commission is working on an ordinance for Basin Management Objectives; monitoring
groundwater re-charge entities and CALFED issues; identifying funding opportunities for
County studies and water projects; tracking water-related State legislation; and providing a venue
for public input on water issues separate from the Board of Supervisors.
Butte County Department of Water and Resource Conservation
The mission of the Butte County Department of Water and Resource Conservation (DWRC) is to
manage and conserve water and other resources for the citizens of Butte County. DWRC is
involved in a wide range of activities, including:6
• Developing an AB 3030 Groundwater Management Plan for areas in the county overlying
the groundwater basin that are not covered by an existing AB 3030 plan;
• Developing a county-wide Integrated Watershed and Resource Conservation Plan;
• Providing support to the Butte County Water Commission in the implementation of
Chapter 33 of the Butte County Code, which is the codified version of the Groundwater
Protection Ordinance passed by majority vote at the November 1996 election;
• Developing and expanding the well-monitoring grid for evaluating groundwater levels to
avoid third-party impacts;
• Managing Butte County’s State Water Project entitlement of 27,500 acre-feet and the
contract with the California Department of Water Resources (including the county’s
water supply contracts with Del Oro Water Company and California Water Service
Company);
• Creating an inventory and analysis of Butte County’s water resources, including supplies
and demands for urban, agricultural, and environmental water now and into the future;
• Providing information for the development of a Butte County Resource Conservation
District as proposed by the Board of Supervisors;
• Participating in watershed planning activities with local watershed groups; and
• Maintaining the Butte Basin Water Users Association groundwater flow model under a
lease agreement with the Association.
Butte Basin Water Users Association
Butte Basin Water Users Association (BBWUA) was formed in 1992, in response to the
following issues:
• The 1987-92 drought;
• The failure to build additional State and federal water storage facilities to accommodate the
state’s rapid population growth;
6 Camp Dresser & McKee. Water Inventory and Analysis Report. 2001.
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• The publicly expressed opinion that Butte Basin groundwater basin was an underutilized
resource; and,
• The need to manage Butte Basin’s surface water and groundwater resources to ensure that
water transfers in or outside the basin do not adversely impact other water users.
The main purpose of the BBWUA is to keep its membership informed of current and potential
future changes in local, State, and federal policies that could affect water supplies. BBWUA was
formed by a Memorandum of Understanding between various water suppliers and users in the
Butte-Sutter area, which provides an open forum for discussion of mutual concerns regarding
water-related issues. As of 2003, members of the BBWUA include:
• Biggs-West Gridley Water District
• Richvale Irrigation District
• County of Butte
• California Water Service Company
• Western Canal Water District
• City of Biggs
• City of Gridley
• Durham Mutual Water Company
BBWUA contracted with a consulting firm, Hydrologic Consultants, Inc. (HCI), to develop a
groundwater model for the service area of the membership. The intended use of the model is to
assess the basin groundwater resources, quantify the resources of the basin, and to assess the
hydrologic impacts on the groundwater system for various water management alternatives.7
Butte County Groundwater Protection Ordinance (Chapter 33)
In November 1996, Butte County voters approved a groundwater conservation ordinance
intended to provide groundwater conservation through local regulation of water transfers outside
of the county with a groundwater component. A permit is now required for both exportation of
groundwater outside the county and groundwater pumping as a substitute for surface water
exported outside the county. A permit for water transfer outside of the county would be denied if
the proposed activity would:
• Cause or increase an overdraft of the groundwater underlying the county;
• Bring about or increase saltwater intrusion;
• Exceed the safe yield of the aquifer or sub-basins underlying the county;
• Result in uncompensated injury to overlying groundwater users or other users; or
• Cause subsidence.
Butte County Well-Spacing Ordinance (Chapter 23B)
The Well-Spacing Ordinance identifies procedures for the proper construction and placement of
water wells, as well as appropriate techniques for destroying abandoned wells.
7 Hydrologic Consultants, Inc., 1996
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Water Resource Planning
Public agencies throughout California have started planning on a watershed scale to address land
use change and development that affect water yield and water quality. In the past, the County
recognized the importance of managing development in the Paradise Irrigation District area
watershed, to protect domestic water supplies for the Town of Paradise and other development in
the area. County zoning regulations identify special standards for development in the area
intended to preserve water quality.
While watershed-level planning and policymaking may be increasing, the large number of
agencies involved in water management creates its own set of problems. In Butte County,
federal, State, and local agencies, irrigation districts, and municipal water providers are serving
the public. Thousands of private landowners divert surface water or pump groundwater. Each
strives to meet its own needs, but not always the interest of the larger community. Recent case
law supports a greater role for counties in the area of groundwater management. The County also
has broad land use planning and regulatory powers which can be used to help manage water
resources throughout the county. Water ordinances have been approved by county voters, and
management plans under State legislation have been prepared to support planning and use of
water resources.
Urban Water Management Plans (AB 797)
The Urban Water Management Planning Act, passed in 1983, requires urban water agencies to
prepare a management plan if they serve more than 3,000 customers, or more than 3,000 acre-
feet of water per year. The management plan is a tool for water management planning and must
identify water supplies and demands, as well as potential additional supplies to meet future
demands. Plans are completed every five years. The most recent plans were due on December
31, 2000. A 20-year projection of demand is included in the plan. The following urban water
agencies are required to submit Urban Water Management Plans:8
• California Water Service, Chico;
• California Water Service, Oroville;
• Del Oro Water Company;
• Paradise Irrigation District;
• Thermalito Irrigation District; and
• Oroville Wyandotte Irrigation District.
A large number of urban agencies have signed a Memorandum of Understanding (MOU) for
urban water conservation in California. Signatories to the MOU are pledged to evaluate and
implement cost-effective Best Management Practices for water conservation.
Agricultural Water Management Plans (AB 3616)
8 Camp Dresser & McKee. Water Inventory and Analysis Report. 2001.
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The California Agricultural Water Management Planning Act of 1986 (AB 1658) and the Federal
Reclamation Reform Act of 1982 historically governed agricultural water management. The
Reclamation Reform Act of 1982 required federal water contractors to prepare Water
Conservation Plans. Enactment of AB 3616 in 1990 formed a committee that resulted in the
development of a list of Efficient Water Management Practices (EWMPs) for agricultural water
supplies. Agricultural water agencies irrigating over 5 million acres of farmland in the state have
developed a MOU to development management plans and implement the EWMPs. In Butte
County, only Western Canal Water District has signed the MOU.
Groundwater Planning
As noted, the Butte Basin Water Users Association (BBWUA), an organization of water users,
has prepared a detailed hydrologic model of the groundwater basin as a potential management
tool to:
1) Assess the groundwater resources of the Butte Basin;
2) Develop a quantitative hydrologic understanding of the groundwater system, and
3) Develop a tool for evaluating regional hydrologic impacts on the aquifer system based
upon various scenarios of withdrawal without damaging its ability to recharge.
The Butte County Water Commission will use the model in considering the issuance of permits
for the export of groundwater outside the county. An extensive well monitoring program is
underway by the California Department of Water Resources in order to assist the development of
the groundwater model, and a variety of agencies are monitoring water levels throughout Butte
County.
The groundwater model can evaluate the effects upon the Butte Basin Aquifer of groundwater
withdrawal or land use changes within sub-basins in the County. This includes modeling the
impact of transfers, artificial recharge projects, increased pumping from urban expansion, and
wetland projects. The model can also simulate the effects of long-term drought conditions and
can provide a comprehensive water resources planning tool for the Butte Basin aquifer.
Groundwater Management Plans (AB 3030)
Assembly Bill AB 3030 (Groundwater Management Act) was passed in September 1992 and
became law in January 1993. The law was enacted to facilitate coordinated groundwater
management among agencies and greater management authority for local agencies on local
groundwater issues.
Groundwater management includes:9
• Protection of natural recharge and use of artificial recharge; planned variation in amount
and location of pumping over time;
• Use of groundwater storage conjunctively with surface water from local and imported
sources; and
9 California Department of Water Resources. Bulletin 118-80. 1980.
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• Protection and planned maintenance of groundwater quality.
An AB 3030 plan is a groundwater management plan for local agencies whose service area
includes all or part of a groundwater basin. The plan outlines the agency’s management activities
and encourages coordinated management of the groundwater basin. In Butte County, the
following agencies have AB 3030 plans:
• Biggs-West Gridley Water District;
• Butte Water District;
• Richvale Irrigation District; and
• Western Canal Water District.
Plans prepared under AB 3030 drew many agencies into groundwater management, and counties
are now heavily involved in groundwater management through ordinances.10 Many plans
prepared under AB 3030, though, have had little or no implementation, and many counties focus
primarily on limiting exports rather than on a comprehensive management program. However,
Butte County is developing an AB 3030 plan for those areas not already covered by such plan,
and is developing a Basin Management Objectives (BMOs) ordinance.
Groundwater management plans prepared under any statutory authority must include the
following components (which are instructive for water planning):11
1) Public participation;
2) Management Objectives (MOs);
3) Components relating to the monitoring and management of groundwater levels,
groundwater quality, inelastic land surface subsidence, and changes in surface flow and
surface water quality that directly affect groundwater levels or quality or are caused by
groundwater pumping;
4) A plan by the managing entity to “involve other agencies whose service area or boundary
overlies the groundwater basin;
5) Adoption of monitoring protocols capable of tracking changes in conditions for the
purpose of meeting BMOs;
6) A map showing the area of the groundwater basin, as well as the boundaries of other local
agencies that overlie the basin; and,
7) For local agencies not overlying groundwater basins, plans shall be prepared including the
above listed components and using geologic and hydrologic principles appropriate to
those areas.
Emerging Issues
During the past ten years, Butte County’s population increased over 11 percent to an estimated
204,000 residents (California Department of Finance, 2001). Continuing statewide population
10 California Department of Water Resources. Draft State Water Plan Update. 2003
11 Ibid.
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growth will require additional water to meet demand, with much of the new demand originating
in water-poor southern California.
Changes in water management have resulted in increased environmental water use. The Bay-
Delta Accord, Central Valley Project Improvement Act, and implementation of CALFED
dedicated more water for environmental purposes, which may affect water supplies available to
agricultural and urban water users in the future.
Butte County appears to have adequate source supplies of both groundwater and surface water to
serve its needs as of 2003.
Northern – Southern California Water Resource Issues
In the northern portion of the state, there is general consensus that, while the chronic
environmental and water resources problems in the Bay-Delta and southern California need to be
resolved, their resolution should not limit the ability of the northern counties to meet their
present and future land use and water resource needs.
Emerging Groundwater Issues
Drought, sustainable groundwater development, and lack of centralized water delivery systems
in certain rural parts of the county are among the most important water resources issues to be
dealt with in the future.
Drought
The 1987-1994 drought is notable for its six-year duration and its statewide impacts.12 During
the drought, the State Water Project terminated deliveries to agricultural contractors and
provided only 30 percent of the total urban deliveries. Governor’s Executive Order No. W-3-91
created a Drought Action Team and directed the DWR to implement a drought water bank. Some
land owners within the Butte Basin area, including agricultural water districts, sold surface water
entitlement to the State Water Bank on a temporary basis, and increased groundwater pumping to
make up the difference. Some farmers in the county contended that increased pumping of
groundwater lowered the water table and adversely affected their wells or significantly
increasing pumping costs.
Several factors have emerged that would increase the level of impact under similar climatic
conditions to those experienced during the 1987 – 1994 drought. California’s population has
increased by six million since the drought and is expected to continue to increase. The State
water management framework has significantly changed, with reduced allocation of Colorado
River water and environmental concerns in the Sacramento-San Joaquin River Delta and San
Francisco Bay.
Groundwater Development
12 Camp Dresser & McKee. Water Inventory and Analysis Report. 2001.
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Butte County General Plan Background Report
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Although local pumping may seasonally depress groundwater levels, pumping generally does not
result in a long-term decrease of storage. An adequate supply of groundwater is available for
future use, however, increased use could require deepening of existing wells.
Though the majority of the county’s foothill population is served with surface water in the
Paradise area, groundwater development in the fractured hard rocks in the foothills of the
southern Cascades and Sierra Nevada is fraught with uncertainty. Groundwater supplies from
fractured rock sources are highly variable in terms of quantity and quality and are an uncertain
source for large-scale residential uses. The infrastructure necessary to transport surface supplies
to many of the county’s small, remote communities is not in place. Historically, foothill
development relied on water supply from springs and river diversions with flumes and ditches
for conveyance, but as of 2003, development uses individual private wells. As pressures for
larger scale development increase, questions about the reliability of supply need to be addressed.
Residents in Cohasset, Forest Ranch, and Magalia have had to rely on water delivered by tanker
trucks. Potential development of regional water supply projects is complicated by the area’s
geographically dispersed development patterns, which do not provide the financial capacity to
support such projects.
Although some residents have had to increase the depth of their wells, there are no areas of
serious overdraft identified in the county. However, there are specific locations suffering from
degraded groundwater quality due to contamination from nitrates and organics.
Statewide Trends
Actions by landowners, local governments, local, State, and federal agencies, and the courts will
continue to shape groundwater management in the future. Increasing population and its demands
on water supply will make groundwater issues more critical. With this thought in mind, some
general conclusions are possible:13
• Groundwater management will likely continue to be a local responsibility with increasing
emphasis on how actions in one part of a basin impact groundwater resources throughout
the basin. Regional cooperation and coordination of groundwater management activities
will likely increase.
• As the State’s population continues to grow, the increased reliance on groundwater will
keep the topic of groundwater management at the forefront of legislative interest.
• The increased reliance on groundwater in the future will necessitate a more direct link
between land use planning, watershed management, floodplain management, and
groundwater management plans.
• Trends indicate that financial incentives in the form of loans and grants are increasing the
amount of groundwater management planning and implementation at the local level.
These successes will likely lead to increased funding to local agencies for groundwater
management planning in the future.
• Groundwater quantity and quality will increasingly be considered as a part of an integrated
water management approach that considers the full range of demands and supplies.
13 California Department of Water Resources. Draft State Water Plan Update. 2003
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
35
Water Resources Issues Advocacy Groups
Following is a description of a cross-section of local organizations that are working to manage
and enhance the use of water resources within the county. The Board of Supervisors is working
with these groups in hopes of generating ideas about alternative ways to manage the resources
(Table 12-6).
TABLE 12-6
ADVOCACY GROUPS
Organization Mission Strategy/Approach
Big Chico Creek
Watershed Alliance
“To seek to establish a local community-
stakeholder partnership effort to develop a
unified watershed management process that will
promote the protection, enhancement, and
stewardship of Big Chico Creek and its
tributaries and to provide educational and
informational benefits to all interested parties”
(Big Chico Creek Watershed Alliance).
The Alliance published a watershed management
strategy for the watershed in November 2000. The
strategy includes the alliance goals, as well as
management strategies and recommended actions to
meet the goals.
Butte Creek
Watershed
Conservancy
“The Butte Creek Watershed Conservancy was
established to protect, restore, and enhance the
cultural, economic, and ecological heritage of
the Butte Creek watershed through cooperative
landowner action” (Butte Creek Watershed,
2000).
The Conservancy published its Watershed
Management Strategy, which is a cooperative
approach between various stakeholders to minimize
resource conflicts and develop a future management
strategy for the watershed.
Little Chico Creek
Watershed Group
The Little Chico Creek Watershed Group was
formed to look at the water quality issues
associated with agricultural and urban use of the
creek.
This group is working with the county to develop a
report on a stream survey, fish survey, land use
review, and management plan review. The Little
Chico Creek Group is also looking to secure funding
to perform additional water quality monitoring.
Butte Environmental
Council
Provide environmental education and
information referral services and advocacy.
The organization’s current water resource focus
centers on responsible land use and development
coupled with preservation of the environment.
Cherokee Watershed
Group
Cherokee Watershed Group is mainly concerned
with water quality, water quantity/supply,
protection from groundwater overdraft, and the
environmental impacts of mining. They are
concerned that Butte County and Northern
California will bear the burden of Bay/Delta
solutions, with potential impacts to aquifers,
water supply, and the existing groundwater
extraction infrastructure.
Formed to have a voice in local water issues and to
gather and disseminate information more effectively.
Durham Library
Group (California
Communities for
Water Protection)
The group’s main focus is related to
groundwater and domestic wells, including
preservation (and discovery) of groundwater
recharge areas, the protection of groundwater as
a resource for farmers, towns, etc, water quality,
and the protection of watersheds.
The Group started meeting in 1997 to address what
they considered to be two important issues: 1) an
under-consideration of citizens and farmers in water
issues and 2) their vision of an unbalanced
representation of the public as a whole on the Butte
County Water Commission. The group intends to
ensure that factual and accurate data is used in
decision-making regarding water use.
Sacramento River
Conservation Area
Advisory Council
To protect, restore, and enhance fisheries and
riparian habitat.
In 1989, the council produced the Upper Sacramento
River Fisheries and Riparian Habitat Management
Plan, which included specific actions to improve
Sacramento River fisheries and a conceptual plan for
riparian habitat. To further develop the riparian plan,
the council published the Sacramento River
Conservation Area Handbook in 1998; this handbook
contained action-oriented plans for riparian habitat in
the conservation area (approximately 210,000 acres).
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
36
Organization Mission Strategy/Approach
Under the Handbook, a Non-profit Organization
(NPO) was developed comprised of 1 landowner and
1 public interest representative from each county
within the conservation area, as well as 1 public
interest representative appointed by the Secretary of
Resources. There are seven counties within the
conservation area, and Butte County’s representatives
are Jane Dolan and Shirley Lewis. There is also a
Technical Advisory Committee (TAC) made up of
agency representatives appointed by the NPO.
(California Department of Water Resources, 1998)
Sacramento River
Preservation Trust
The organization was formed in response to the
Bank Protection project with the purpose of
promoting an ecological approach to river
preservation. SRPT has since then been working
to protect the natural values of the Sacramento
River ecosystem.
The organization’s main water resource areas of
interest include wildlife issues (both aquatic and
terrestrial), groundwater issues, and water
quantity/supply. Within Butte County SRPT has
worked with the Butte Creek Watershed project, but
the focus of the organization is more regional in
scope. SRPT feels that the understanding and proper
application of the relationship between surface water
and groundwater is the main water resource issue
facing Butte County. (J. Merz, 2001)
Valley Water
Protection
Association
At that time many were either dependant upon
groundwater or saw it as critical and felt that
there was no advocate in the area for
groundwater. The organization formed in order
to be that voice. The VWPA is concerned
mainly with water supply and the
environmental, political, geographical, and
economic impacts of water decisions.
Since their organization the VWPA has written many
letters of support/concern for various water-related
projects like CALFED and other Environmental
Impact Reports involving local development. They
also played a critical role in petitioning for Measure
F, the alternative Groundwater Protection proposition
on the ballot in 1996.
Source: Camp Dresser & McKee, 2001.
12.2 TREATMENT AND CONVEYANCE SYSTEMS
Adequate domestic water service for the county’s urban population is crucial for public health,
community sanitation, and fire protection. Water rights and resources are often the focus of
public water policy, but water delivery systems and purveyors are important in achieving water
resources objectives. Improvement, coordination, and expansion of water treatment and
conveyance systems represent an opportunity to implement water resource conservation and
other County water policies.
Water Providers
The county’s domestic and agricultural water needs are met through a network of local agencies.
Irrigation districts are designed to ensure delivery of sufficient water supplies for agricultural
uses, though they serve some residential and commercial uses.
Domestic water supply in the county is managed by local water companies and water districts.
This water supply includes water for drinking, residential, and commercial uses. A significant
portion of domestic water is obtained through private residential wells.
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Final Draft August 8, 2005
Butte County General Plan Background Report
37
Mutual water companies are private corporations that perform water supply and distribution
functions similar to public water districts, such as Cal Water Service Company. Investor-owned
utilities may also be involved in water supply activities, sometimes as an adjunct of hydroelectric
power development.
Public water systems and irrigation districts in Butte County include (Figure 12-9):
• City of Biggs
• Cal Water Service Company (Chico)
• Cal Water Service Company (Oroville)
• Del Oro Water Company (Lime Saddle)
• Del Oro Water Company (Paradise Pines)
• Del Oro Water Company (Stirling City)
• Western Canal Water District
• Richvale Irrigation District
• Table Mountain Irrigation District
• Buzztail Community Service District
• Berry Creek Community Service District
• Biggs-West Gridley Water District
• Butte Water
• Lake Madrone Water
• Durham Irrigation District
• City of Gridley
• Oroville Wyandotte Irrigation District (Bangor)
• Oroville Wyandotte Irrigation District (Miners Ranch)
• Paradise Irrigation District
• Thermalito Irrigation District
Table 12-7 summarizes county water systems, including descriptions of the planned, proposed,
or required improvements for each of the systems. Five of the systems summarized below use
surface water, five use groundwater, and one uses both. These systems served 159,160 county
residents and delivered over 14 million gallons of water to the residential, commercial, industrial,
and agricultural users in 1990. Approximately 25 million gallons of storage capacity is available
to the distributing systems. Chlorination is the primary method of disinfection for both
groundwater and surface water systems (Table 12-8).
Butte County
General Plan
Figure 12-9
WATER PROVIDERS
Source: Camp Dresser & McKee, 2001.
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
39
TABLE 12-7
PLANNED WATER SYSTEM IMPROVEMENTS
Water System Planned, Proposed or Required Improvement
Berry Creek Community
Service District
No growth or projects planned. Water provided by well. Treated with chlorine as needed. Have one
90,000 gallon tank. Serves approximately 100 residents. Delivers approximately 1,500 gallons per
hour.
Biggs-West Gridley
Water District
Irrigation purposes only. No plans for improvements. Surface water from Feather River (pre-1914
water rights; 1967 agreement with State). Expansion of conveyance system to 750 cubic feet per
second (cfs).
Butte Water Irrigation purposes only. (Share water rights with Biggs-West Gridley Water District and Richvale
Irrigation District)
Buzztail Community
Service District Installing a 60,000 gallon holding tank. Expecting two new residential connections for a total of 14.
Cal Water - Chico Adding more wells and upgrades of existing well stations as more land is annexed within District
boundary. No significant planned projects.
Cal Water - Oroville No significant planned improvements.
City of Biggs Implementation of water meters on all new connections; accelerated main line replacement program.
City of Gridley Continued 20 main line replacement program. Additional wells and main replacement.
Dayton Mutual Water
Company N/A
Del Oro - Lime Saddle Construction of water treatment plant and transmission line to Lake Oroville.
Del Oro - Paradise No significant planned improvements.
Del Oro - Stirling City No planned improvements. No improvements needed.
Durham Irrigation
District
Additional wells will be drilled to serve additional development; beginning or supplemental to look
into alternate surface water supply.
Durham Mutual Water
Company N/A
Lake Madrone Water Installed a 100-gallon water tank that now brings district storage capacity to 145,000 gallons.
Oroville-Wyandotte
Irrigation District Pipeline replacement program for urban water deliveries.
Paradise Irrigation
District Accelerated pipeline replacement program.
Richvale Irrigation
District
Receives 149,000 ac. ft. of water annually. May expand water distribution to the period between
November and January.
Table Mountain
Irrigation District Irrigation purposes only - no residents served. Approximately 325,850 gallons per year.
Thermalito Irrigation
District
Continued main line replacement program, addition of sedimentation basins. Water treatment plant
needs replacement in 6 to 8 years.
Western Canal Irrigation purposes only - no residents served. No improvements necessary. Approximately 260,000
acre feet per year.
Sources: DHS file information; DHS staff interviews, County staff interviews and files, system managers and operators, August 1995 and 1998,
2000, and 2001; Urban Water Management reports collected in 2003.
Chapter 12: Water Resources
Final Draft August 8, 2005
Butte County General Plan Background Report
40
TABLE 12-8
WATER SYSTEMS SUMMARY
Water Purveyor Resident
Population
Annual
Delivery Source/s of Water Treatment Practices and
Capacities
Storage
Available
(in millions
of gallons)
Biggs-West
Gridley Water
District
N/A 161 TAF Surface N/A 0
Cal Water Service
- Chico 80,000 25.4 TAF 63 active deep wells All wells are chlorinated 1.375
Cal Water Service
Co. - Oroville 9,620 4.85 TAF
4 wells, west branch of
Feather River, Wilenor
Reservoir
Full treatment of surface
water/ 6,300 gpm/
fluoridation of wells
7.2
City of Biggs 1,603 212 2 wells Chlorination 0.04
City of Gridley 4,869 497 4 deep wells Fluoridate all wells and
chlorinate two 0.30
Dayton Mutual
Water Co.N/A N/A Butte Creek and West
Branch of Feather River N/A N/A
Del Oro Water
Co. - Lime Saddle 706 37
Two wells plus Paradise
Irrigation District surface
water
Chlorination/soon full
treatment at a treatment plant 0.22
Del Oro Water
Co. – Magalia
258
connections N/A
Two wells plus Paradise
Irrigation District surface
water
N/A 0
Del Oro Water
Co. - Paradise
Pines
9,189 430 5 wells plus surface water
from Stirling Bluffs District None 1.24
Del Oro Water
Co. – Stirling
Bluffs
N/A N/A Hendrick Canal N/A 0
Durham Irrigation
District 1,500 345 acre-feet 4 wells None .005
Durham Mutual
Water Co.N/A N/A N/A N/A N/A
Oroville -
Wyandotte
Irrigation District
17,000 27 TAF South Fork Feather River,
Yuba River
14.5 million gallons treated
per day (MGD)6.56
Paradise Irrigation
District 25,772 8,200 TAF Little Butte Creek and wells Full treatment at treatment
plant/22.8 MGD 3.9
Richvale
Irrigation District N/A N/A
Surface water from Little
Dry Creek, Thermalito
Afterbay, supplemented
with groundwater during
rice field flooding.
N/A N/A
Thermalito
Irrigation District 9,400 2,800 TAF Concow Dam releases and
five back-up wells
Treatment Plant and well
chlorination/9.5 MGD 3.00
Sources: DHS file information; DHS staff interviews, County staff interviews and files, system managers and operators, August 1995 and 1998,
2000, and 2001; Urban Water Management reports collected in 2003. TAF = thousand acre-feet. Annual delivery in acre-feet unless otherwise
specified.
Chapter 12: Water Resources
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Butte County General Plan Background Report
41
Water providers in the county are supplied by both surface sources and groundwater from wells.
As of 1990, 159,160 county residents were delivered more than 14 million gallons of water
through water providers for residential, commercial, industrial, and agricultural needs.
Biggs-West Gridley Water District
Biggs-West Gridley Water District occupies 32,000 acres. Of Biggs-West Gridley’s total area,
27,346 acres are irrigated for agriculture and managed wetland uses. Biggs-West Gridley also
provided water to 8,500 acres of the Gray Lodge Wildlife Area, of which 2,600 acres are within
their service area. In 2003, Gray Lodge intends to use wells instead of surface water from Biggs-
West Gridley for wetlands water.
Some landowners within the district have backup wells to make up for water lost during
droughts, or to provide all water during droughts so that the remaining surface water can be
marketed. However, the district itself has no production wells. Biggs-West Gridley has up to
3,000 acres of “second status” lands that were brought into the District after 1979. During years
when the California Department of Water Resources (DWR) reduces water deliveries, the second
status lands are the first to have their water deliveries reduced. Biggs-West Gridley is chronically
water short. The district has an entitlement of 161 thousand acre-feet (TAF), but has been 5 TAF
short for the past 5 years. In these years, they have bought added supply from other districts
within the Joint Board. They also have a recapture system that provides approximately 25 TAF
and could serve as an additional drought management tool. There are no surface storage facilities
within the district.
Biggs-West Gridley has a system of canals to distribute water throughout their service area, and
they estimate that the system loses one percent of its volume for every mile of conveyance from
seepage, evapotranspiration, and associated losses. As of 2003, the conveyance system in Biggs-
West Gridley is handling 700 cubic feet per second (CFS) of diversions during the summer, but
it was not designed for this flow. DWR and the United State Bureau of Reclamation (USBR) are
considering an expansion of the conveyance system to 850 CFS to provide capacity to send more
water through Biggs-West Gridley’s system to Gray Lodge. Of pressing concern for Biggs-West
Gridley is the need to expand its conveyance capacity, which it must do to serve its existing
customers. If the State or federal government does not pay for the expansion, Biggs-West
Gridley will try to expand the system incrementally to 750 CFS instead of 850 CFS.
Biggs-West Gridley has the following statewide concerns:
• CALFED governance might include only agency representatives, without nonagency
stakeholder representation;
• CALFED could result in agricultural land conversion and does not give adequate credit to
farmers for wetlands on their lands;
• Phase 8 of the SWRCB hearings could set unpopular precedents;14
14 Phase 8 is structured to determine responsibilities of Sacramento River Basin water right holders. Operators of the state and
federal projects reached an agreement with the Sacramento Basin and project contractors that the operators would assume
responsibility for Bay-Delta standards compliance while the parties identify and implement projects to increase the
Sacramento Basin yield. Should cooperative efforts falter; the project operators will request the SWRCB to reactivate its
hearings.
Chapter 12: Water Resources
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Butte County General Plan Background Report
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• TMDL could impact agricultural drainage implementation; and
• Endangered Species Act requirements to protect habitat could limit activities within their
distribution system.
Durham Mutual Water Company
Durham Mutual Water Company was created by area residents. The company provides surface
water for agricultural uses from Butte Creek. Durham Mutual Water Company is part of the
Butte Creek adjudication, and has first priority rights to 44.7 CFS. The water is diverted at
Durham Mutual Dam, and is then conveyed to customers in the service area.
Richvale Irrigation District
Richvale has a riparian water right on Little Dry Creek for 18,300 acre-feet that can only be used
during April – September. It also receives 150 thousand acre-feet from the Joint Board pursuant
to pre-1914 water rights. The district encompasses a land area of approximately 33,000 irrigable
acres in Butte County. Richvale distributes its water supplies annually during the irrigation
season, commencing by charging its water distribution system with surface water supplies from
Thermalito Afterbay in April each year, and completing its water distribution by October 31 each
year. The district may continue water distribution from November to January for rice straw
decomposition, to benefit wildlife habitat in the Butte Basin, and to comply with restrictions on
rice straw burning.
Some groundwater pumping occurs within Richvale, which is used primarily as a supplemental
source of water during the initial flooding of rice fields. Richvale does not have estimates of the
quantity of groundwater pumped.
The major concern of the District is the outcome of the CALFED process and its potential impact
on water resources within Butte County.
Thermalito Irrigation District
There is a population of approximately 9,400 in the district and around 2,500 connections.
Agriculture has slowly declined within the district due to a combination of factors, including
marginal soil. Thermalito now delivers only potable water to a combination of residential,
industrial, and governmental users. Thermalito obtains its surface water from the Concow
Reservoir (also known as Wilenor Reservoir). The water enters the West Branch of the Feather
River through Concow Creek, then is released from Oroville Dam and delivered to the district
through the Thermalito Power Canal. Thermalito also has five groundwater wells and a total
capacity of 10 MGD (11.2 TAF/yr). Groundwater is used only as a backup. In 2000,
approximately 2,800 acre-feet of water were supplied within the service area.
The district stores some of its water in a 2.5 million-gallon storage tank in the distribution center,
and another 7,225 acre-feet within Concow Reservoir. Losses of water within the district are
believed to be insignificant.
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Butte County General Plan Background Report
43
Thermalito is trying to extend water mains to vacant land to help accelerate development. The
District estimated that the water treatment plant will need to be expanded within 8 to 10 years.
The plant does not have sedimentation basins, so it cannot handle increased turbidity. During
times with high turbidity, Thermalito uses its groundwater wells to supplement supplies.
Thermalito is planning to add sedimentation basins when it can acquire the land to make
additions to the plant.
Thermalito is concerned on a county-wide level about groundwater overdraft, and believes that
surface water options should be fully utilized. The county has a State Water Project allocation of
27,500 acre-feet, but they have never exercised the full allocation because the water is more
expensive than other sources in the county. The District fears that if Butte County does not use
their State Water Project (SWP) allocation, they could lose it.
California Water Service Company, Oroville
California Water Service Company, Oroville (Calwater-Oroville) is a private water supplier that
purchased a local water district in Oroville in 1927. Calwater-Oroville provides water within the
Oroville city limits, minus areas served by other Oroville water suppliers (Thermalito Irrigation
District and Oroville-Wyandotte Irrigation District). The population within Calwater-Oroville is
approximately 9,620, and almost all of the water that Calwater-Oroville provides is dedicated to
urban use (residential, industrial, and commercial). The company does provide agricultural water
to farmers along the delivery canal. However, during a drought the agricultural users are the first
to be cut back.
The average water quantity supplied by the company is 4.85 TAF/yr. The peak daily use is
approximately 6.5 MGD. The average daily use during high demand is 5.5 MGD. Calwater-
Oroville has two reservoirs and two storage tanks, providing a total of 7.209 million gallons of
storage. Conveyance losses are difficult to determine with any certainty because routine
operations spill water from the system into the Feather River. Losses in the distribution system
are a minor concern.
Calwater-Oroville has several concerns within their service area. It would first like to expand
supply. Future options for more water include building more storage tanks and drilling new
wells. The City of Oroville is prepared to help with some of this expansion, and has set aside
parcels of land for these facilities. Water is spilled from the Miocene Canal into the State’s
system. The State charges Calwater-Oroville for any SWP water that it uses, but does not
provide a credit for water spilled from the canal. Calwater-Oroville is also concerned that the
county will not fully utilize its allotment of SWP water, which could mean that the water
entitlement would be decreased or lost.
Western Canal Water District
The district encompasses a land area of approximately 59,000 irrigable acres in both Butte and
Glenn Counties, with approximately 30,700 acres in the East Butte Inventory Unit and 14,000 in
the West Butte Inventory Unit.
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Butte County General Plan Background Report
44
The supply is provided by two outlet structures located on the northwest corner of the Thermalito
Afterbay. The maximum combined outlet flow is 1,250 cubic feet per second. The pre-1914
surface water rights comprise 150,000 acre-feet of natural flow from the Feather River and
145,000 acre-feet of upstream stored water in the Feather River North Fork Project. There also
exists a water right on Butte Creek for 11,400 acre-feet, which can be diverted only during the
period of April 15 through June 15. Many landowners in the District have constructed deep wells
(at their own expense) to provide a conjunctive-use capability. A number of the farms to the
north of the main canal were entirely dependent upon groundwater supplies until canals and low-
lift pumps were installed (at landowners’ expense) to provide surface water supply. As of 2003,
groundwater use within the district boundaries is estimated to be 7,000 acre-feet. The
conveyance losses within the district are estimated to be about 12 to 13 percent.
Del Oro Water Company
Del Oro Water Company serves the unincorporated urban areas around the Town of Paradise.
Del Oro has four separate service areas:
• Lime Saddle,
• Magalia,
• Paradise Pines, and
• Stirling Bluffs.
The Lime Saddle District is approximately 4.3 square miles, with 265 service connections
(primarily residential). All connections are metered, and losses are not found to be significant.
Lime Saddle has two groundwater wells, and has an agreement with Paradise Irrigation District
to receive treated surface water. The agreement stipulates that they will treat up to 266 acre-feet
per year, and will deliver that amount minus 10 percent assumed conveyance losses. The
groundwater wells in Lime Saddle do not bear much water, and have produced slightly less than
50 acre-feet per year in recent years.
The Magalia District has 258 connections that are primarily residential. Magalia has two
groundwater wells, which produced approximately 38 acre-feet in 1999. Magalia also receives
some water from Paradise Irrigation District.
The Paradise Pines District utilizes groundwater, with 4,440 metered connections and 562
additional services. In addition to local groundwater wells, Paradise Pines receives surface water
from the Stirling Bluffs District. The primary water service is for single family residential
dwellings. Paradise Pines has five active groundwater wells, which produced 1,375 acre-feet in
1999.
Stirling Bluffs has a contract to receive up to 365 acre-feet per year of water from PG&E through
the Hendrick Canal. In 1999, they diverted 86.64 acre-feet of this water. The remaining water
from Stirling Bluffs is available for transfer to Paradise Reservoir, which Paradise Irrigation
District treats and wheels to Paradise Pines, Magalia, or Lime Saddle. Of the 365 acre-feet, 266
acre-feet is dedicated to Lime Saddle as described above, and most of the remaining water is
used in Paradise Pines.
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Paradise Irrigation District
Paradise Irrigation District is approximately 11,250 acres in size. In 2000, the district used
approximately 8,200 acre-feet of water within their service area, including water losses. Paradise
serves 25,772 people, and has 10,000 connections serving 13,000 dwelling units. Paradise
anticipates an approximately 20 percent growth rate through 2020. This growth will increase the
population as of 2003 of 25,772 people to approximately 31,000. Treated water in the district is
used for both agricultural and domestic purposes, with approximately 6 percent of the district’s
water used to irrigate orchards.
In 1956, the District constructed the new Paradise Dam and Reservoir, with a storage capacity of
8,350 acre-feet. The Dam was raised by 24.5 feet in 1976, which increased the capacity to
11,497 acre-feet. In 1996, seismic concerns in Magalia Reservoir forced the District to keep
water levels below the maximum capacity, which has reduced the capacity from 2,500 acre-feet
to approximately 800 acre-feet. The District completed construction of a new water treatment
plant in 1995 with the capacity to treat 22.8 million gallons of water per day.
There is a 15 percent (1,250 acre-feet) system-wide loss from the distribution system that
Paradise began to repair in 1994 when losses reached 30 percent. Older steel pipelines are being
replaced by PVC to reduce system leakage. Paradise does not have supply problems in normal
runoff years, but is vulnerable to several dry years in a row. In addition, Paradise is surrounded
by the Del Oro Water Company’s service area, and is potentially impacted by its problems. The
Paradise Pines and Lime Saddle areas rely on Stirling Bluffs water. Del Oro has no storage, so it
is very susceptible to droughts. Discussions are underway to consider a two-mile pipeline that
would carry water from Lake Oroville to Lime Saddle and Paradise Irrigation District. Current
estimates of cost range from $300-$350 per connection for Pines and Lime Saddle users.
Paradise Irrigation District staff believes that a long-term drought would require demand
reduction. Paradise currently has one well to use as a drought management tool, and they have
plans to install an additional well that would provide 200 to 300 acre-feet of supply. A study is
underway to determine the feasibility of additional water sources. There are no groundwater
quality concerns, although septic tanks are the only means of sewage disposal in the district.
South Feather Water and Power Agency
The South Feather Water and Power Agency (formerly the Oroville-Wyandotte Irrigation
District) district encompasses 38,320 acres. It serves a population of 17,000, with 6,120 domestic
water accounts and 525 irrigation accounts. Urban demand is expected to rise as the historical
growth rate of 1.2 percent is increased because of the Oroville community’s accelerated
expansion plans.
Supplied water is used for agricultural, residential, and commercial purposes. South Feather
Water and Power Agency has four major reservoirs: Sly Creek, Lost Creek, Ponderosa, and
Miner’s Ranch. These total approximately 172 TAF of storage. Sly Creek Reservoir is fed
partially by Slate Creek, which is part of the Yuba River system. Yuba County Water Authority
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receives water through the Forbestown Ditch from Sly Creek Reservoir. The remainder of the
water is for South Feather Water and Power Agency use. There are three canal systems within
the district that provide raw water to agricultural customers: Forbestown, Bangor, and Palermo.
South Feather Water and Power Agency does not use groundwater but there are some pockets of
land within the district that have independent private wells.
South Feather Water and Power Agency has both pre-1914 and appropriative water rights
totaling 800 TAF, which is more water than is available from within the watershed. The district
can take 172,145 acre-feet of water from the South Fork of the Feather River and the Yuba River
and store it in its reservoirs. South Feather Water and Power Agency uses 27 TAF of water
within their service area. The system is 100 percent metered (or volume-measured for raw water
delivery systems, using instruments such as “miner’s-inch” boxes).
Losses within the domestic system are believed to be negligible. In 1990, there were up to 160
leaks due to the poor condition of the old steel pipeline system, but with repairs there are now
only 6-7 leaks. South Feather Water and Power Agency has a steel pipeline replacement project
underway for their urban deliveries. Losses in the agricultural systems are more significant, with
93 percent in the Forbestown Canal, and approximately 70 to 80 percent in the remainder of the
system. South Feather Water and Power Agency has coated with concrete the canal areas with
profuse leaks and fixed sections with major leaks. Consideration has been given to rehabilitating
the entire ditch system. The ditch system is already subsidized by the power division, so the
District cannot justify spending additional money on that system. The District would consider
repairing the leaks if it could sell the water, but wheeling fees charged by the DWR have made
transfers financially prohibitive.
California Water Service Company, Chico
California Water Service Company, Chico (Calwater Chico) is a private company that has been
serving the water supply needs of the greater Chico area since 1926, when it purchased three
smaller districts in the area. The greater Chico area includes some areas of Butte County as well
as the city of Chico. There are approximately 90,000 people in the service area, but Calwater
Chico does not provide water to the entire population within the service area because there are
some private wells sprinkled within this area. Supplied water is used solely for urban purposes.
Calwater Chico has no surface water supply, so it takes all of its water from 63 deep wells. On
average, the company supplies 25.4 TAF a year.
Calwater Chico believes that droughts are not a major concern because the groundwater supply
in the area is plentiful and easily accessible. There are five tanks (four above ground) that are
used for storage, for a total combined storage of 1.375 million gallons. Leaks in the distribution
system are minimal.
Within the Chico urban area, there are 21,602 sewer connections and 12,000 septic tank users.
Calwater Chico does not foresee any supply problems within its service area. Its management
believes that the water supply is adequate for future growth. This assumption is reinforced by the
Butte Basin Water Users Association groundwater model. The company plans to drill additional
wells and pump more water to fulfill higher future demands. On a county-wide level, Calwater
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Chico plans to ensure that groundwater is utilized within the Butte basin before it is transferred
elsewhere.
Dayton Mutual Water Company
Dayton Mutual Water Company provides surface water to meet the area’s agricultural water
needs. Dayton Mutual has water rights to Butte Creek and the West Branch of the Feather River
(diverted through Butte Creek) totaling 19.334 CFS.
Durham Irrigation District
The population residing within the district is approximately 1,500, with service connections
numbering about 400. Expected growth is estimated to be 20 to 30 connections per year. The
average annual water delivery for the period from 1995 to 1999 was 345 acre-feet. The average
water supplied per capita is estimated at 200 gallons per day. The projected increase in demand
is expected to be 4 to 5 acre-feet per year. The District’s water source comes from three
groundwater wells. The district also has 5,000 gallons of storage in the system.
Major concerns of the District include lowering of the groundwater table and potential drinking
water contamination due to an increase in the number of independent domestic and agricultural
wells, and potential damage to the groundwater basin due to “out of basin” transfers of
groundwater, either directly or by in-lieu groundwater substitution pumping associated with
surface water transfers.
Storage Facilities
While the county is nearly devoid of natural lakes, there are numerous man-made impoundments
that store some of the county’s abundant surface water for water supply, as well as provide flood
protection. Oroville Dam and reservoir on the Feather River is the second largest water storage
facility in California and is the initial and largest reservoir of the State Water Project. Its waters
serve many users, both within the county and beyond, including users in southern California.
Lake Oroville
Oroville Dam was completed in 1968 to serve as the headwaters to the California State Water
Project. Oroville Dam is the highest dam in the United States, standing 770 feet above the stream
bed and containing 22 square miles of surface water. Approximately one third of the water
volume stored in the lake is transported to southern California each year. Of the water conveyed
from Lake Oroville through the aqueduct system:
• 59 percent of the water is delivered south of the Tehachapi Mountains to southern
California, supplying approximately 12 million people;
• 32 percent is supplied to the San Joaquin Valley, enough water to irrigate 600 square miles;
• 4.5 percent of the project water is delivered to users south of San Francisco Bay; and
• 4.5 percent is delivered for municipal and industrial users north of San Francisco Bay, in
the Central Coastal area and near the Feather River;
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Butte County has contracted with the DWR Oroville water supply to supplement existing
municipal and industrial supplies. The County has an allocation of 27,500 acre-feet that was
agreed upon as a mitigation measure for accepting Oroville Dam.15 The County did not want to
pay for water it could not use, so it developed an agreement where the amount of water available
each year would start small and slowly grow to the full allocation. There have been a series of
amendments to delay the time when the full 27,500 acre-feet is allocated to the county because
the county is still not ready to use the full allocation. Thermalito Irrigation District, Oroville-
Wyandotte Irrigation District, Biggs-West Gridley, Western Canal, and Richvale water districts
divert water through SWP facilities under their own water rights. Thermalito can divert 8,200
acre-feet a year and Oroville-Wyandotte can divert 17,555 acre-feet per year.
Aside from water deliveries for agriculture, municipal uses and power consumption, Oroville
Dam is a major flood control and protection facility, and Lake Oroville supports many
recreational uses, as well as irrigation, municipal water supply, flood control, and wildlife
habitat. An ancillary use of the Lake Oroville dam is the downstream Feather River Hatchery.
The hatchery was constructed to mitigate the loss of salmonid habitat resulting from construction
of the dam.
Thermalito Forebay and Afterbay
The Thermalito Afterbay and Forebay work together as a system to generate power. The
reservoirs are used for recreational activities and irrigation and support wildlife habitat.
Paradise and Magalia Reservoirs
Paradise Reservoir (also known as Paradise Lake) is located on Little Butte Creek about four
miles north of Magalia in Butte County. The reservoir was formed by the construction of
Paradise Dam in 1957 and is one of two reservoirs (Paradise and Magalia Reservoirs) that supply
the town of Paradise with water. 16 The reservoir is also used for some recreational activities. The
reservoir capacity is 11,500 acre-feet. In 1996, seismic concerns in Magalia Reservoir forced the
District to keep water levels below the maximum capacity, which has reduced the capacity from
2,500 acre-feet to approximately 800 acre-feet.
Other Surface Water Storage Facilities
Butte County has numerous water storage reservoirs, some of which fall under the jurisdiction of
the Department of Water Resources Division of Dam Safety. Table 12-9 lists dams within Butte
County within jurisdiction of the Division of Dam Safety, including information on the dam
name, owner, year completed, stream dammed and storage capacity.
15 Camp Dresser & McKee. Water Inventory and Analysis. 2001.
16 California Department of Water Resources. [Online]. www.dpla.water.ca.gov. 2002.
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TABLE 12-9
DIVISION OF DAM SAFETY JURISDICTION
BUTTE COUNTY DAMS
Name Owner Year
Completed Stream
Storage
Capacity
(Acre-Ft.)
Al Chaffin George Chaffin 1957 Cottonwood Creek Tributary 450
California Park California Park Homeowners
Association 1986 Dead Horse Slough 335
Cannon Ranch Spring Valley Minerals 1870 Oregon Gulch Tributary 176
Concow Thermalito Table Mountain
Irrigation District 1925 Concow Creek 8,600
Desabla Forebay Pacific Gas and Electric Co.1903 Middle Butte Creek 280
Feather R
Hatchery
State Department of Water
Resources 1964 Feather River 580
Forbestown
Division
Oroville Wyandotte Irrigation
District 1962 South Fork Feather River 358
Grizzly Creek Mr. & Mrs. Ronald T. Dreisbach 1964 Grizzly Creek 76
Kunkle Pacific Gas and Electric Co.1907 West Branch Feather River
Tributary 253
Lake Madrone Lake Madrone Water District 1931 Berry Creek 200
Lake Wyandotte Oroville Wyandotte Irrigation
District 1924 North Honcut Creek 1,300
Lost Creek Oroville Wyandotte Irrigation
District 1924 Lost Creek 5,680
Magalia Paradise Irrigation District 1918 Little Butte Creek 2,900
Miners Ranch Oroville Wyandotte Irrigation
District 1962 North Honcut Creek Tributary 912
Oroville State Department of Water
Resources 1968 Feather River 3,537,577
Paradise Paradise Irrigation District 1957 Little Butte Creek 11,500
Philbrook Pacific Gas and Electric Co.1926 Philbrook Creek 5,180
Poe Pacific Gas and Electric Co.1959 North Fork Feather River 1,150
Ponderosa
Division
Oroville Wyandotte Irrigation
District 1962 South Fork Feather River 4,750
Round Valley Pacific Gas and Electric Co.1877 West Branch Feather River 1,147
Sly Creek Oroville Wyandotte Irrigation
District 1961 Lost Creek 65,050
Thermalito
Afterbay
State Department of Water
Resources 1967 Feather River Tributary 57,041
Thermalito
Division
State Department of Water
Resources 1967 Feather River 13,328
Thermalito
Forebay
State Department of Water
Resources 1967 Cottonwood Creek Tributary 11,768
Source: Camp Dresser & McKee, 2001.
Regulatory Setting
The California Safe Drinking Water Act ensures clean drinking water for the state. The provision
of domestic water in the county is regulated by the California Department of Health Services for
projects with more than 200 service connections, while the Butte County Department of
Environmental Health regulates projects involving less than 200 service connections. In addition,
AB 1803, passed in 1985, requires monitoring of public drinking water wells for organic
chemicals. Although the County does not have a monitoring program as of 2003, the
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Environmental Health Department is working with the State Department of Health Services in
developing a program to fulfill this edict. The Environmental Health Department has indicated
that the overall quality of the drinking water is above average.
Emerging Issues
In many of the foothill and mountainous areas of the county, where development pressures
would be expected in the future, water is not always readily available through individual wells.
In remote areas where this condition exists, community or mutual water systems will be
necessary.
Irrigation districts are meeting demands without significant problems. With the exception of
water supply difficulties instigated by drought conditions, no future difficulties are anticipated in
any of these districts. Most agricultural areas have lower population growth rates than urban
centers. Most irrigation districts do not expect population increases of more than two to three
percent annually.
As of 2003, there are no problems with domestic water supply; however, significant population
growth in and around the county’s urban areas warrants consideration of future demand, as well
as development of policies that ensure a stable supply and efficient use of domestic water.
12.3 WATER QUALITY
Water quality is influenced by natural factors and by the activities of people. Quality of water
changes as it moves through the water cycle, stages which are as follows:
• Water vapor mixes with gas in dust and clouds
• Vapor condenses around small particles to form rain or snow
• Evaporation increases concentration of mineral in water left on earth
• Changes in water quality in lakes due to physical, chemical and biological processes
• Quality of surface water is modified by contact with soil and air
• Surface water quality is further modified by chemical reaction among salts, sediment and
biological materials in water
• Groundwater is modified chemically and physically by the minerals and gases dissolved
from the rocks
• Salt water from oceans mixes with fresh water from the rivers (surface water)
• Mixing along salt/fresh water interface (groundwater); this is called the estuarian zone - the
edge of the sea where salt water combines with fresh
• Water quality in oceans is altered by physical, chemical and biological processes
• Dust and spray are picked up by air movement from the land and/or water surface and
introduced into the atmosphere
Increasing population, development, commercial, industrial, and agricultural activity can result
in adverse impacts to water quality. Degradation of water quality can occur through disposal of
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mine waste or agricultural runoff, discharge of improperly treated wastewater, sediments, or
processes that affect the temperature of the water. Irrigation increases concentration of salts in
water. Economic and population growth not only increases the demand for water resources, it
simultaneously produces more waste and wastewater that reach watercourses. The benefits of
using water to transport waste away from the home, factory, or farm must be balanced with the
costs to the environment and water quality.
Existing Conditions
In general, surface water in the county is of a quality level suitable for agricultural use. Butte
County has many outstanding waterways that serve as sources of domestic water supply and for
recreation and fisheries. Groundwater from the Butte Basin has also been historically of good
quality for farming, municipal, and domestic uses.
The relationship of storm water runoff to the maintenance of surface and groundwater quality is
critical. During the “first flush” of fall rains, pollutants that have accumulated on the surface of
the land, especially impervious surfaces, are washed into the drainage system and can enter
surface water bodies or the groundwater.
Groundwater quality in the Sacramento River Hydrologic Region is generally excellent.
Moderate levels of hydrogen sulfide occur in groundwater in the volcanic and geothermal areas
in the western portion of the region. Some Sierra foothills areas have uranium and radon-bearing
rock or sulfide mineral deposits containing heavy metals. Individual septic system development
has affected areas of Butte County, such as the Chico area, where a program is underway to
establish municipal treatment of wastewater to replace septic systems that have led to nitrate
infiltration. Septic effluent especially affects water quality in shallow unconfined portions of
aquifers or in fractured hard rock areas where insufficient soil depths are available to properly
leach effluent before it reaches the local groundwater supply.
Water Quality in Public Supply Wells
Between 1994 and 2000, public supply wells in the Sacramento River Hydrologic Region were
sampled, and 72 percent met California Safe Drinking Water standards (drinking water
legislation is detailed below). Of the exceedances, natural constituents, such as inorganics and
radiological contaminants accounted for 88 percent, while exceedances resulting from human
activity accounted for about 12 percent.
Water quality in Butte County is substantially better than that for the Sacramento Hydrologic
Region as a whole. Water quality standard exceedances are shown in Table 12-10 for Butte
County sub-basins.
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TABLE 12-10
BUTTE COUNTY SUB-BASIN WATER QUALITY
Public Supply Wells Exceeding California Safe Drinking Water Standards
(# wells sampled in parentheses)
Groundwater
Quality (Total
Dissolved Solids in
mg./L)17Name
Inorganic
Primary Radiol
ogical
Nitrates Pesticides
Volatile
Organic
Compounds18
Inorganic
Secondary Average Range
Vina 0 (52)0 (49)4 (56)0 (49)4 (48)1 (52)285 48 - 543
West Butte 0 (29)0 (25)0 (30)0 (26)1 (26)2 (29)293 130 - 676
East Butte 1 (30)0 (25)2 (32)0 (16)0 (19)3 (30)235 122 - 570
North Yuba 0 (27)1 (23)1 (35)0 (23)2 (24)7 (27)N/A N/A
TOTAL BUTTE COUNTY SUB-BASINS
Exceedances 1 1 7 0 7 13
Total
Sampled 138 122 153 114 117 138
ALL
CONSTITUENTS
Percentage
Compliance 99%99%95%100%94%91%96%
Source: Department of Water Resources, 2003.
Regulatory Background
All suppliers of domestic water to the public are subject to regulations adopted by the U.S.
Environmental Protection Agency under the Safe Drinking Water Act as well as by the
California Department of Health Services under the California Safe Drinking Water Plan Act.
State and federal regulations addressing water quality are summarized below.
Federal Regulations
Clean Water Act-National Pollutant Discharge Elimination System
Section 402 of the Clean Water Act established a permit system known as the National Pollutant
Discharge Elimination System (NPDES) to regulate point sources of discharges in navigable
waters of the United States. The U.S. EPA was given the authority to implement the NPDES,
although the act also authorizes states to implement the act in lieu of the EPA. As described
below, in 1972, the Legislature amended the Porter-Cologne Act to give California the authority
and ability to operate the NPDES permits program. Before a NPDES permit is issued, the local
Regional Water Quality Control Board (RWQCB) must certify that the discharge will comply
with applicable water quality standards. In 1987, Section 402 was amended to require the
regulation of storm water runoff under the NPDES.
Safe Drinking Water Act
The federal Safe Drinking Water Act (SDWA), enacted in 1974 and amended in 1986 and 1996,
directed the EPA to set national standards for drinking water quality. It required the EPA to set
17 Total dissolved solids (TDS) are measure of dissolved materials in water indicating salinity. For many purposes, TDS
concentration is a major limitation on the use of water.
18 Volatile organic compounds have high vapor pressure and low water solubility, and are typically are industrial solvents,
constituents in petroleum fuel products, or by-products produced by chlorination in water treatment.
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maximum contaminant levels (MCL) for pollutants. Local water suppliers are required to
monitor their water supplies to assure that regulatory standards are not violated.
State Regulations
Porter-Cologne Water Quality Control Act
Porter-Cologne is the State’s comprehensive water quality control law and is a complete
regulatory program designed to protect water quality and ensure its beneficial use. The act
requires adoption of water quality control plans by the State’s nine RWQCBs, subject to the
approval of the State Water Resources Control Board (SWRCB), and ultimately the U.S. EPA.
To implement the plan, any party conducting activity that could discharge waste into waters of
the state must meet formal waste discharge requirements. Waste discharge requirements must be
consistent with the water quality control plan. The Central Valley Regional Water Quality
Control Board sets standards and enforces the regulations for the discharge of human and
industrial effluent into the waterways of the county and monitors sewage treatment facilities and
their operation.
California Safe Drinking Water Act
In 1976, California enacted its own Safe Drinking Water Act, requiring the Department of Health
Services (DHS) to regulate drinking water, including:
• Setting and enforcing federal and State drinking water standards;
• Administering water quality testing programs; and,
• Administering permits for public water system operations.
The standards established by DHS are found in the California Code of Regulations, Title 22.
Emerging Issues
There are two general water quality areas of concern in the county:
1) Improperly treated waste reaching mountain and foothill rivers and streams. Waste
discharge requires treatment for suspended and settleable solids, biological degradable
organic substances, bio-stimulatory nutrients, toxic substances, and chloroform
organisms to maintain the existing water quality control conditions.
2) Improperly treated waste reaching lowland fresh waters. Waste discharge to these waters
requires removing suspended and settleable solids, biological degradable organic
substances, bio-stimulatory nutrients, toxic substances and chloroform organisms and
nutrients are reduced to a level that will assure against bio-stimulation of surface waters.
Water reclamation and planning for irrigation and other uses of water is important in the
lowland areas where most county water is used.
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An adequate supply of water of a quality suitable for all uses requires water quality management.
Pollution abatement, waste treatment, efficient use of water, recycling of industrial water for
reuse, and reservoir release to increase low streams flows are widely used management
techniques. Water quality management will receive increased attention in the future plans of
water development.
Pollutants of Concern
Coliform bacteria, solvents, and salts have contributed to water quality problems in the county.
In the Chico area and the Town of Paradise area there have been excessive levels of coliform
bacteria or nitrates entering the groundwater. Failed septic systems, or too many septic systems
in a concentrated area, are probable causes. Surface water quality is also at risk from potential
chemical spills, such as occurred in 1991 as a result of a train derailment on the upper
Sacramento River.
The Central Valley Regional Water Quality Control Board directed the abandonment of septic
systems in the Chico Urban Area, and directed the County to prepare a Groundwater Nitrate
Compliance Program. Groundwater in the area became contaminated with nitrates from home
septic systems, many of which are in the unincorporated area surrounding the city. The County
and City of Chico are working to connect homes to the City of Chico’s regional sewer treatment
plant. Approximately 3,500 dwellings are to remain on septic systems, which will be inspected
and repaired or replaced, as necessary. The plan has encountered delays because annexation of
unincorporated parcels is required. Many landowners believe that the Nitrate Compliance
Program is a ploy to force annexation and should be waived. Another concern is the high cost
that individual homeowners may incur connecting to the sewer. It is imperative that the State,
County and the City of Chico, along with the affected property owners, maintain a cooperative
and focused effort to mitigate and solve this threat to the public health.
Future Water Quality Measures
Butte County would benefit from research on water quality issues such as:
• Salt balance of irrigated valleys;
• Waste treatment and water use;
• Effect of conservation measures on sediment yields;
• Effect of herbicides, pesticides and commercial fertilizers on water supply;
• Effect of high water temperature on some fish life and aquatic plants;
• Effect of surface storage on the chemical quality of water;
• Assessment of future water requirements; and,
• Measurement of sediment bedloads.
Based on this research, development proposals in the county could be evaluated on the basis of
their potential for water use and wastewater disposal. Those projects that do not conform to the
standards set by the California Water Resources Board would have the burden of showing that
the development will not have a detrimental effect on the water quality of the county.
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Source Water Quality
Unexpected circumstances involving water can contribute to water quality problems. Drought
can concentrate contaminants and flooding can cause sediment loading, as well as wash other
pollutants into surface water.
Changing conditions require adjustments to treatment, blending of waters from different sources,
and other water management methods to maintain drinking water standards. New information on
health effects of pollutants leads to periodic changes in state and federal drinking water
standards. Standards have become more restrictive over time, introducing uncertainty in water
supply and treatment planning. Protecting source water quality protects against this uncertainty,
as protecting source water quality is less costly than treating polluted water for use.
Agricultural Irrigation
Irrigation water is drained away from the root zone naturally or in drainage infrastructure. This
drainage water, which picks up salts and chemicals from the soil, can create water quality
problems for the receiving surface or groundwater. Agricultural drainage is one of the largest
contributors of human-induced contamination of surface and groundwater in California. Public
agencies in agricultural areas of the state are studying drainage problems and developing
drainage managements strategies based on this information.
12.4 EXISTING SUPPLY AND DEMAND
Historic and present day water demand is presented in the following section to provide baseline
water balance information, inform policymakers, and provide a basis for forward projection of
supply and demand. The results of this analysis will provide both a viable basis for planning and
support information dissemination and consensus development among the county stakeholders.
Historic Water Development
As with many California counties abutting the Sierra Nevada, the lure of gold resulted in the first
organized use of the county’s water resources, though with population growth, other water uses
emerged. Mining companies in Butte County began constructing ditches for hydraulic mining as
early as 1860. Prior to 1870, only a few farmers experimented with irrigating their lands with
water from wells or streams, as many farmers emigrated from the Midwest, where they had
practiced “dry farming.” Butte County farmers soon began using the Feather River for irrigation.
As the agricultural industry expanded in Butte County, local water districts began to look for
more secure water supplies. Several districts constructed upstream reservoirs to capture heavy
winter and spring flows for use during the irrigation season. Other areas of the county, without
access to surface water supplies, began to become increasingly dependent on groundwater as a
reliable source of water.
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The State Water Project (SWP) was approved in 1960, and the California Department of Water
Resources (DWR) started construction of Oroville Dam in 1961, which created Lake Oroville, a
3.5 million acre-feet (MAF) storage reservoir. Land and water use within Butte County was
impacted by the construction of Oroville Dam. Existing facilities for water suppliers within the
county were flooded, and the upstream migration of fish was halted at Oroville. As a part of the
construction of the dam, Thermalito Forebay and Afterbay were also built to regulate the
temperature of the water before it is released into the Feather River. If the water is too cold, it
has the potential to damage rice production.
Existing Demand
The county was divided into water inventory units based on hydrologic basins and common
water sources. The six units are Vina, West Butte, East Butte, North Yuba, Foothill, and
Mountain (Figure 12-10). Existing water demand is presented in the following section according
to water inventory units. The water supplies and demands were assessed for each sub-unit for
both normal and dry years under 1997 population and land use conditions. Table 12-11 lists the
inventory units and water suppliers within inventory unit boundaries.
TABLE 12-11
INVENTORY UNITS AND WATER SUPPLIERS
Inventory Units Water Suppliers
Biggs-West Gridley Water District
Butte Water District
City of Biggs
City of Gridley
Durham Mutual Water District
Richvale Irrigation District
Thermalito Irrigation District
East Butte
Western Canal Water District
Paradise Irrigation District
Del Oro Water CompanyFoothill
Oroville Wyandotte Irrigation District
Mountain N/A
North Yuba California Water Service, Oroville
Vina California Water Service, Chico
California Water Service, Chico
Dayton Mutual Water District
Durham Irrigation DistrictWest Butte
Western Canal Water District
Source: Camp Dresser & McKee, 2001.
Table 12-12 summarizes water demand for normal years, including conveyance losses, which
represent the amount of water required to convey supplies to their destination, and include free
water surface evaporation, evapotranspiration by canal riparian areas, percolation into the
groundwater, and spillage from the system.
The majority of the demand occurs in the valley areas of the county, due to increased urban
population and extensive farming areas. Inventory units in the valley have higher demands than
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those in the foothill or mountain ranges. The greatest demand is in the East Butte inventory unit
(64 percent), followed by West Butte (18 percent) Vina (10 percent), North Yuba (5 percent),
Foothill (2 percent) and Mountain (1 percent). The Mountain Inventory Unit has very high
conveyance losses compared to the water use. These losses are attributed to the large losses
through Oroville-Wyandotte’s delivery canals, which are very leaky and date back to the Gold
Rush era.
Butte County
General Plan
Figure 12-10
INVENTORY UNITS
Source: Camp Dresser & McKee, 2001.
No Scale.
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TABLE 12-12
NORMAL YEAR WATER DEMAND (IN THOUSANDS OF ACRE-FEET)
Inventory Unit Agricultural Municipal &
Industrial Environmental Conveyance
Losses1
Total Applied
Water
East Butte 629.6 9.5 124.0 167.6 930.7
Foothill 7.3 14.8 0.0 5.0 27.1
Mountain 1.1 1.8 0.0 9.4 12.3
North Yuba 54.0 6.7 1.2 5.2 67.1
Vina 121.5 19.7 0.0 2.7 143.9
West Butte 201.1 10.3 14.0 40.2 265.6
County Total 1,014.6 62.8 139.2 230.1 1,446.7
Source: Camp Dresser & McKee, 2001.
Existing Supply
Table 12-13 illustrates the normal year supplies for each inventory unit and sub-unit. These
supplies indicate the amount of water necessary to meet demands. Therefore, the supplies will be
equal to or less than the demand amount in each area. The various surface water supply sources
are separated, including local surface water, Feather River water, and deliveries from the SWP or
Central Valley Project. Some general observations are noteworthy:
• The East Butte and Foothill Inventory Units primarily use surface-water, and the remainder
of the county primarily uses groundwater.
• The primary water source within the county is surface water (55 percent), followed by
groundwater (31 percent) and surface water reuse (14 percent).
• Supplies are distributed throughout the county in the same pattern as demands, with the
most water going to the East Butte inventory unit (64 percent), followed by West Butte
(18 percent), Vina (10 percent), North Yuba (5 percent), Foothill (2 percent) and
Mountain (1 percent).
• Butte County’s supply of 1.4 million acre-feet is approximately 1.8 percent of the total
California water supply of 79.5 million acre-feet.
• During normal years, there are no shortages.
TABLE 12-13
NORMAL YEAR SUPPLIES (IN THOUSANDS OF ACRE-FEET)
Inventory Unit Local Surface Water Feather River SWP CVP Groundwater Surface Water Reuse Total Supplies
East Butte 38.3 576.0 0.0 11.2 124.6 180.6 930.7
Foothill 10.0 12.4 0.0 0.0 3.2 1.5 27.1
Mountain 0.0 8.4 0.0 0.0 2.0 1.9 12.3
North Yuba 0.0 13.3 0.0 0.0 50.2 3.6 67.1
Vina 0.0 0.0 0.0 2.8 138.2 2.9 143.9
West Butte 17.1 70.7 0.0 26.6 121.0 29.6 265.6
County Total 66.0 680.8 0.0 40.6 439.2 220.1 1,446.7
Source: Camp Dresser & McKee, 2001.
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Drought Year Demand versus Supply
In most areas, drought demands are greater than normal year demands. Shortages are shown in
Table 12-14 below for inventory sub-units, which are smaller divisions of the inventory units in
the county that are drawn based on water districts and hydrologic characteristics.
Shortages are concentrated in the southwestern portion of the county. Supply is limited by the
groundwater infrastructure available in the southwest, not by total water supply. The water
shortage in ridge areas is somewhat different than the other areas, and is caused by a lack of
surface water infrastructure. The shortage in Cohasset is due to a lack of groundwater depth and
infrastructure.
Richvale, Biggs-West Gridley, and Butte are all part of the Joint Water District, which has
adequate surface water supplies during normal years. During normal years, it is not economical
for farmers to pump groundwater; so many farmers do not have the necessary infrastructure.
Shortages only occur in areas that do not receive surface water and do not have the infrastructure
to pump groundwater.
TABLE 12-14
WATER SHORTAGES AND DEMAND DURING DROUGHT YEAR
Inventory Unit Sub-Unit
Shortage
Thousand Acre-Feet (TAF)
Total Demand
Thousand Acre-Feet (TAF)
Biggs-West Gridley 37.4 208.2
Butte 13.5 111.5
Butte Sink 3.1 52.2
Cherokee 3.2 31.9
Richvale 33.6 252.9
East Butte
Total 90.8 655.7
Cohasset 0.1 0.5
Ridge 1.2 13.1
Foothill
Total 1.3 13.6
County Total 92.1 669.3
Source: Camp Dresser & McKee, 2001.
Urban
Water delivered to meet urban demand was assessed through a review of local urban water
management plans (AB 797), interviews with water managers, and annual summaries of urban
water production data submitted by urban suppliers to DWR. Several areas with urban
development are not served by an urban water supplier, so these data are not available. Per capita
estimates of urban areas with similar characteristics were applied to these areas to produce urban
demands for all areas. In addition, rural per capita use was estimated to establish domestic well
extractions throughout the county.
Table 12-15 shows the 1997 population in each inventory unit.
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TABLE 12-15
POPULATION PER INVENTORY UNIT
Inventory Unit/Sub-Unit Population
East Butte Inventory Unit 25,438
Mountain Inventory Unit 5,729
Foothill Inventory Unit 56,256
North Yuba Inventory Unit 19,142
Vina Inventory Unit 61,062
West Butte Inventory Unit 30,871
County Total Population 198,498
Source: Camp Dresser & McKee, 2001.
Agricultural
Agricultural water demand includes irrigation water requirements for all crops. Agriculture
produces the majority of county demand, with 71 percent of the total demand. The remaining
demand is composed of conveyance losses (15 percent), environmental demands (10 percent),
and urban demands (4 percent).
Environmental
Applied water demands for managed wetlands include state and federal wildlife refuges, publicly
or privately managed wetland habitat, and agricultural lands flooded for rice straw
decomposition or duck habitat.
Within the county, much of the rice acreage is flooded following harvest for the purpose of
decomposing the remaining rice straw, which provides some habitat value to migratory birds.
Water circulation is especially important when managing an area for waterfowl habitat because
harmful diseases can breed in stagnant water.
These factors were combined to develop an Evapotranspiration of Applied Water (ETAW) for
each wetland area that was included in the regional demand projections. ETAW refers to the total
applied amount of water. As for agricultural lands, the ETAW for these areas was estimated
using the habitat types within each wetlands area.
12.5 FUTURE WATER SUPPLY AND DEMAND
Future Water Demand by Use
Various methods are used to project or forecast demands, and will be used in the Integrated
Watershed and Resource Conservation Plan being developed by the County. Butte County’s
urban water needs will increase in the future. For example, Paradise Irrigation District estimates
that trends in its demands indicate an increase of about 10 percent by 2020 in their urban water
management plan.19 Agricultural demand for water has remained static in the Sacramento Valley,
19 Camp Dresser & McKee. Water Inventory and Analysis. 2001.
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but there has been no comprehensive effort to forecast future cropping patterns, irrigation
methods, and water supplies. In addition to agricultural and residential/commercial needs of the
county’s developed and developing areas, water-dependent habitats and the life these habitats
sustain require water resources for survival. Wetlands in particular support a rich diversity of
life, and often flora and fauna that is considered threatened or endangered by the State or federal
government. Diverting water from wetlands for urban or agricultural needs can result in
irreparable harm to such sensitive environments. Environmental water demand may increase as
more wildlife and waterfowl areas (including wetlands and riparian habitat mitigation banks) are
set aside. However, there has been little analysis of environmental water use trends in the county.
Water Conservation Potential
A Memorandum of Understanding Regarding Urban Water conservation in California provided
the basis for the demand management measures in the Urban Water Management Planning Act
and in forecasts of future urban demands. Urban Best Management Practices (BMPs) have been
identified for use in Urban Water Management Plans, and include the following:
• Water survey programs for single-family and multi-family residential customers;
• Residential plumbing retrofit;
• System water audits, leak detection, and repair;
• Metering with commodity rates for all new connections and retrofit of existing
connections;
• Large landscape conservation programs and incentives;
• High-efficiency washing machine rebate programs;
• Public information programs;
• School education programs;
• Conservation programs for commercial, industrial, and institutional accounts;
• Wholesale agency assistance programs;
• Conservation pricing;
• Conservation coordinator;
• Water waste prohibition; and
• Residential Underground Leaking Fuel Tank replacement programs.
In Butte County, conservation practices such as the following are in effect:
• Conservation requirements for plumbing in new construction;
• Public information programs about water conservation;
• Water audits; and
• Leak detection and repair.
Del Oro Water Company and California Water Service are signatory to the MOU regarding
urban water conservation in California The MOU formed the Urban Water Conservation
Council, which is implementing Urban BMPs in the state.
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Water Recycling
Water recycling is a potential source of supply for groundwater recharge. The amount of treated
effluent generated in Butte County is small compared to the overall water supply. Additionally,
like conservation, it will be most cost-effective in coastal areas where the effluent is lost to the
ocean and can’t be reused. There is little need for much analysis in this area, but it could become
more important in the future as the number of sewer connection increases.
Water Pricing
Water pricing encourages water conservation, recovers environmental costs, or recovers other
external costs. Some water districts in Butte County meter their water to charge by the amount
used, while others charge a flat rate. Statewide, there are major differences in water pricing,
based on different timing of water rights, different infrastructure costs, and varying operation and
maintenance costs. Since newer facilities are more expensive, water providers decide between
charging the new customers the actual incremental cost through higher connection fees, or
combining new costs with the older system costs to be paid by all customers. Drinking water
costs at least several hundred dollars per acre-foot. Agricultural water is more variable, ranging
from a few dollars per acre-foot to several hundred dollars per acre-foot. One of the biggest
challenges in water pricing is how to price water in water contracts.20
20 California Department of Water Resources. Water Plan Update. 2003.