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INTRODUCTION
The
principal arena for the Sonoma County Water Agency is the
drainage basin or watershed of the Russian River. The
Russian River watershed covers an area of approximately
1,480 square miles contained within Mendocino and Sonoma
Counties. It traverses 84 miles to its confluence with
the Pacific Ocean. It's 100 mile main stem flows
southward in parallel with the Pacific Ocean and through the
fertile agricultural and wine grape growing regions of the
Potter Valley, Ukiah Valley, Hopland Valley, Cloverdale
Valley, Alexander Valley and the Santa Rosa Plains.
Most of the population in the North Coast Region lives in
and around Santa Rosa. Smaller creeks have been dammed
to create ponds for irrigation, stock watering and frost
control. Over 100 creeks have been fully or partially
channelized for flood control, effecting their natural
functions. Logging practices have severely damaged
tributaries. Dams have cutoff fish passages to prime
spawning territories. Upon completion of the Coyote Dam
alone, the river channel had significantly changed with
summer flows regulated through dam releases and along with
the Scott Dam and Potter Valley diversion changed the
occasionally dry riverbed into one which flowed all
year.
Extreme
bank erosion and river bed degradation has been enacted
through dams stopping sediment and by the practice of
excessive gravel mining. The connected aquifer has
been impacted by riverbed drop and local water tables and
drinking wells have been impacted. A principal bridge
on Highway 101 has been undercut by down cutting in the
riverbed of 22 feet in the past 40 years. The
replacement of the bridge is expected to cost taxpayers in
the amount of $11 million. Terrace gravel mining has
been allowed on over 100 acres with pits reaching depths of
80 feet. The capture of the pits by flood action on
unengineered levees is a future devastation waiting to
happen. Ninety-five (95) percent of the Coho salmon
have been lost.
Impounded
water that draws from and feeds into the Russian River is
located in Lake Mendocino (Coyote Dam), Lake Sonoma (Warm
Springs Dam), Lake Pillsbury (Scotts Dam and Van Arsdale
Dam), and many small dams on the feeding tributaries.
. The Department of Water Resources has designated the
Russian River as Class I or excellent to good as a result of
the dilution of boron levels with the increased from from
Coyote Dam. River pH falls in the slightly basic to
neutral range of 7.2-8.8. Irrigation water uses serve
approximately 30,000 acres in Mendocino and Sonoma
County. Approximately 500,000 people are served
through urban water use.
Water
appropriations and riparian rights are issued by the State
Water Resources Control Board. The are 1,404 water
right permits with 82 unpermitted applications seeking
authority to appropriate water. The 1,404 water right
filings include 77 small domestic use filings, 197 state
filings, 15 stock pond filings, 17 hydropower production
filings, and 1,158 applications, permits and licenses. There
is little or no metering of agricultural withdrawal in
Mendocino and in Sonoma counties. The accompanying
aquifer which abuts the Russian River has long been a
primary water source. The question is, who owns the
water and who or what has first right to the use of the
water.
Eel River
The
Eel River is the third largest river system in the state
with a mean annual discharge of 5.4 million acre feet of
water and its drainage basin covers approximately 3,684
miles in Humboldt, Mendocino, Trinity, Lake and Glenn
counties. The Eel River is contained in the mainstem Eel,
Middle Fork, North Fork, South Fork and the Van Duzen Rivers
for a system of 3,488 stream miles. Eel River water
diversion at the Van Arsdale Dam point of diversion
represents 33% of the Eel River flow at that point. In
certain seasons, 70% of the flow of water in the Russian
River is Eel River water.
Russian River
The
Russian River is fed by the diversion of the Eel River and
by the natural water flow from over 80 tributaries
originating in Humboldt, Lake, Mendocino and Sonoma
Counties. Large creek systems are comprised of Big Sulphur
Creek, Pieta Creek, Forsythe Creek, Feliz Creek, Maacamas
Creek, Mark West Creek, Austin Creek and Dry Creek. The main
river channel begins as two forks (east and west) just
upstream of Ukiah located in Mendocino County. The
watershed is comprised of flat, alluvial valleys made up of
the Ukiah, Hopland, Alexander and the Middle Reach. It
has three canyons at Squaw Rock, Fitch Mountain and at the
Wohler Bridge. The river reaches tidewater at Duncan's
Mills and enters the ocean at Jenner. It takes two
days for the water to flow from the headwaters to the
mouth.
Rainfall and Releases
Available
precipitation data indicates that 90% of precipitation
occurs within the Russian River watershed during the months
of November through April. Total precipitation at the
Ukiah and Healdsburg gages, respectively, were at the lowest
in the recorded water year 1923-24 at 13.09 total rain in
inches per year, and 1976-77 at 16.92 total rain in inches
per year. The highest level in a water year for Ukiah
and Healdsburg gauges, respectively, were in 1982-83 at
68.06 and 83.26 total rain in inches per year. Highest
flood peak was reached in the 1986 flood with a peak of
102,000 cubic feet per second (cfs) at Guerneville. Historic
average annual flows are 706.79 cfs at Hopland, 957.12 cfs
at Cloverdale, 1,406.97 cfs near Healdsburg, and 2,277.13
cfs near Guerneville. It has been estimated at
one time that between 1,900,000 acre fee per annum (afa) and
4-5 million afa flows down the Russian River. Wohler
another estimate has been made that the natural runoff in
the river has varied from a low of 250,000 acre-feet to an
excess of 2.5 million acre-feet.
A review
of the relationship between flow and precipitation during
pre-Sonoma Lake and post-Sonoma Lake periods indicates that
there appears to be a slight increase in depletion from the
watershed.
Russian River Hydrologic Basins and Water Use
Demands
The
Russian River service area consists of several hydrologic
basins comprised of the Forsythe, Coyote, Upper Russian,
Coastal Sonoma, Middle Russian, Dry Creek, Austin, Santa
Rosa, South Sonoma, Lower Russian, Bodega and East and West
Marin.
The
Forsythe includes the drainage upstream from the Russian
River East Fork confluence and includes Redwood
Valley. The 1980 total annual withdrawal in acre-feet
was approximately 500; the projected annual demand by 2010
is estimated to be 4,447 acre feet. The Coyote
Basin is located along the East Fork of the Russian and
includes Potter Valley. It includes mostly agriculture
development and will have an annual dry year demand in 2010
of 10,560 acre-feet.
The Upper
Russian follows the Russian to approximately five miles
north of Cloverdale and includes the Ukiah and Hopland
Valleys. The Upper includes some urban but mostly
agriculture development with urban demand by 2010 needing
7,670 acre-feet and dry year agriculture by 2010 needing
18,600 acre-feet.
The Middle
Russian is above the Dry Creek confluence and includes
Cloverdale, Geyserville and Healdsburg. Urban demand
will reach 5,440 acre-feet by 2010 and agricultural demand
for dry-year will be 12,810 acre-feet.
The Dry
Creek basin includes the Dry Creek Watershed and the Warm
Springs Dam (Lake Sonoma). Urban demand is estimated
to be 2,290 and dry year agricultural demand is to be 2,390
by year 2010.
The Lower
Russian basin is downstream of the Dry Creek confluence and
includes numerous urban water users outside the Russian
River Basin, including the Petaluma River basin, Sonoma
Creek basin and Marin County. The urban demand is
projected to be 90,332 acre-feet per annum. Dependent
users, Sebastopol, Larkfield, Lawndale, Kenwood Village and
Penngrove principally rely on groundwater, yet they may
require 1,792 acre-feet of surface water by 2010.
Windsor and the Airport may need 4,725 acre-feet. The
Russian River Water District anticipates requiring 300
acre-feet.
Cloverdale, Geyserville and Healdsburg depend on Lake
Mendocino and Lake Pillsbury water. Lake Mendocino
holds 92,000 acre-foot and Lake Pillsbury has an 81,100
acre-foot capacity. Lake Pillsbury water, which goes
down the Eel River, is diverted to Lake Mendocino through
PG&E's hydroelectric power plant at Potter Valley and
maintains a flow of water at Healdsburg of 165 cubic feet
per second. Steam developers at The Geysers withdraw water
from tributary feeder streams to the Russian River. The
community of Windsor draws groundwater from the Russian
River above the SCWA diversion point at the Wohler-Mirabel
intakes.
SCWA
anticipates that it could supply the year 2010 needs of its
present customers with its present appropriation rates, but
the growing needs of other communities could not be met
without further appropriation or encroachment of it's 30%
curtailment. The 30% curtailment is the criteria
wherein the water in storage in Lake Sonoma declines to
certain prescribed levels and this calls for reduced water
use. How much demand for more water can be
accommodated depends upon how frequently the 30% diversion
curtailment is deemed acceptable to the homeowners and
industry owners. The maximum annual lower Russian
River urban demand which can be satisfied under the 30
percent curtailment criteria without Lake Sonoma dropping
below the minimum pool is approximately 112,500 acre-feet
per year.
Minimum
stream flow requirements are a water supply demand placed on
the SCWA Russian River system. In a normal year the
water that must be allowed to pass under the Hacienda
Bridge is 80.8 mgd or 90,495 acre-feet per year.
In a critically dry year this can be reduced to 22.6 mgd or
25,340 acre-feet per year. The estimated year 2010 use
will allow over 90 percent of the natural flow to past the
Hacienda Bridge. With approximately 43,000 acre feet
for agriculture and 121,000 acre-feet for urban, there will
still be a stream flow requirement in 2010 of 1,552,000 acre
feet or 505,720,752,000 gallons that is 1,552,000 x 325,851
gallons per acre foot. (In another document, SCWA estimated
Russian River Water demands by 2010 of urban demand to be
141,716 afa and the agricultural demand to be 47,030
afa.)
The SCWA
has stated that the Russian River water supply is adequate
to satisfy all identified water demands which are likely to
be placed upon it in Sonoma and Mendocino counties in the
foreseeable future. Future contracts with Sonoma or
Mendocino County entities which operate public water systems
to allow diversions under Agency appropriative water rights
permits could and probably would advance the date when an
increase in the appropriative water right permit diversion
limits will be necessary.
Russian River Channel
The
Russian River has a long-term trend toward channel
degradation. In the most impacted area of the Middle Reach,
the degradation has reached a depth of over 20 feet from its
1940 bed elevation. beginning in 1940, at the confluence of
the Russian River and Dry Creek mining was done up to 55
feet below the water level with large pits extending over
approximately three miles. It is impacted from
sediment increase due to agricultural impacts and forestry
logging practices. Instream and terrace gravel mining
have contributed greatly to the degradation with large pits
remaining that pose potential pit capture (as happened in
the flood of 1995) and the movement of the river into
another channel. Agricultural reclamation, Rip rap and
levees have forced the river into a narrow and straight
channel. Dams have stopped the natural inflow of
replenishment gravel and have effected the natural flow of
water, while changing the natural seasonal water depths and
the seasonal water temperatures. Land development for
urban growth and agricultural development have effected the
normal pattern of water runoff, water availability and water
quality.
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