KLAMATH PROJECT
2004 OPERATIONS PLAN
April 7, 2004
INTRODUCTION
This is the 2004 Operations Plan (Plan) for the
Bureau of Reclamation’s (Reclamation) Klamath
Project (Project), which is located within the upper
Klamath River Basin in southern Oregon and northern
California. This Plan describes Project operations
from April 1, 2004 through March 31, 2005 based upon
current and expected hydrologic conditions and
consistent with the biological opinions issued by
the U.S. Fish and Wildlife Service (Service) and
National Oceanic and Atmospheric Administration (NOAA)
Fisheries (formerly the National Marine Fisheries
Service). The Plan is initially derived from the
April 1, 2004 Natural Resource Conservation Service
(NRCS) inflow forecast. Reclamation developed this
Plan to serve as a planning aid for agricultural
water users, Klamath Basin Tribes, national wildlife
refuges and other interested parties. Operating the
Project in the manner described in this Plan is
consistent with the Department of the Interior’s and
Reclamation’s tribal trust responsibilities in the
Klamath Basin and we will continue to consult on a
government-to-government basis with the Klamath
Basin Tribes throughout the operating year on
Project operations. A planning process for
multi-year operations of Project through 2012 is
ongoing. Attachment A summarizes the planning
methodology Reclamation used to develop the Plan.
This plan provides an estimated Project water
supply to the following areas:
- Upper Klamath Lake delivery area:
This
area generally includes lands in Oregon and
California that receive Project water primarily
from Upper Klamath Lake (UKL) and/or the Klamath
River. This area also includes the Tule Lake and
Lower Klamath National Wildlife Refuges.
- East Side delivery area
: This area
generally includes lands within the Langell Valley
Irrigation District and Horsefly Irrigation
District on the east side of the Project area.
This area receives water from Clear Lake
Reservoir, Gerber Reservoir and the Lost River.
UPPER KLAMATH LAKE (UKL) DELIVERY AREA
1. ESTIMATED INFLOW TO UKL DURING 2004:
- The predicted inflow (in acre-feet) to UKL
from April 1 through September 30, 2004, using the
NRCS forecast at 50% exceedance, is 420,000
acre-feet for lake elevation operational
criteria; and at 70% exceedance, is 366,000
acre-feet for river flow operational criteria.
2. UKL WATER YEAR TYPE DURING 2004:
- The initial water year type applicable to
Upper Klamath Lake is BELOW AVERAGE for
lake elevation operations planning, subject to
changes to actual hydrologic conditions subsequent
to April 1. Table 1 shows the four water
year types used for lake elevation operations
planning:
Table 1. UKL Water Year Types for
Lake Elevation Planning
|
Water Year Type |
Above Average |
Below Average |
Dry |
Critical Dry |
UKL
Inflow (1000 acre-feet) |
More than 500 |
500 to 312 |
312 to 185 |
Less than 185 |
Occurrence(s) during 10-yr period |
1993, 1995, 1996, 1997, 1998,
1999 |
1990 |
1991 |
1992, 1994 |
The initial water year type applicable to the
Klamath River is BELOW AVERAGE for river
flow operations planning, subject to changes in
actual hydrologic conditions subsequent to April
1. Table 2 shows the five water year types
for river flow operations planning:
Table 2. UKL Water Year Types for
River Flow Planning
|
Water Year Type |
Wet |
Above Average |
Average |
Below Average |
Dry |
UKL
Inflow
(1000 acre-feet) |
More than 785.2 |
785.2 to 568.6 |
568.5 to 458.4 |
458.3 to 286.8 |
Less than 286.8 |
Occurrences(s) during 10-yr period |
1999 |
1993, 1996, 1998 |
1995, 1997 |
1990 |
1991, 1992, 1994 |
3. LAKE ELEVATION AND RIVER FLOW OPERATIONAL
CRITERIA FOR UKL:
- Reclamation will operate the Project to ensure
that elevations in UKL do not recede lower than
the average end-of-month elevations that occurred
between October 1, 1989 and September 30, 1999
(the "ten-year" period) for the corresponding
water year type. Table 3 displays these
elevations:
Table 3. Lake Elevation
Operational Criteria for UKL
|
Water Year Type |
Above Average |
Below Average |
Dry |
Critical Dry |
March 31 |
4142.5 |
4142.7 |
4141.7 |
4142.0 |
April 30 |
4142.9 |
4142.8 |
4142.2 |
4141.9 |
May
31 |
4143.1 |
4142.7 |
4142.4 |
4141.4 |
June
30 |
4142.6 |
4142.1 |
4141.5 |
4140.1 |
July
31 |
4141.5 |
4140.7 |
4140.3 |
4138.9 |
August 31 |
4140.5 |
4139.6 |
4139.0 |
4137.6 |
September 30 |
4139.8 |
4138.9 |
4138.2 |
4137.1 |
October 31 |
4139.7 |
4138.8 |
4138.2 |
4137.3 |
November 30 |
4140.3 |
4139.0 |
4139.0 |
4138.1 |
December 31 |
4141.0 |
4138.8 |
4139.7 |
4138.9 |
January 31 |
4141.5 |
4139.5 |
4140.3 |
4140.1 |
February 28 |
4141.9 |
4141.7 |
4140.4 |
4141.1 |
- Reclamation will operate the Project to ensure
that Klamath River flows at Iron Gate Dam (IGD)
meet or exceed the operational criteria in Table
4. Table 4 incorporates revisions made to Table
5.9 consistent with the Reasonable and Prudent
Alternative in the final biological opinion.
Table 4. Klamath River Operational
Criteria for Flows at IGD
|
Water Year Type and Flow
(cubic feet/second) |
Wet |
Above Average |
Average |
Below Average |
Dry |
April 1-15 |
5932 |
2955 |
1863 |
1826 |
822 |
April 16-30 |
5636 |
2967 |
2791 |
1431 |
739 |
May
1-15 |
3760 |
2204 |
2784 |
1021 |
676 |
May
16-31 |
2486 |
1529 |
1466 |
1043 |
731 |
June
1-15 |
1948 |
1538 |
827 |
959 |
641 |
June
16-30 |
1921 |
934 |
1163 |
746 |
617 |
July
1-15 |
1359 |
710 |
756 |
736 |
516 |
July
16-31 |
1314 |
710 |
735 |
724 |
515 |
August |
1149 |
1039 |
1040 |
979 |
560 |
September |
1341 |
1316 |
1300 |
1168 |
731 |
October |
1430 |
1346 |
1345 |
1345 |
907 |
November |
1822 |
1414 |
1337 |
1324 |
899 |
December |
1822 |
1387 |
1682 |
1621 |
916 |
January |
2792 |
1300 |
3618 |
1334 |
1030 |
February |
4163 |
1300 |
1300 |
1806 |
673 |
March 1-15 |
8018 |
1953 |
2143 |
2190 |
688 |
March 16-31 |
6649 |
4009 |
2553 |
1896 |
695 |
- The river flow operational criteria include
the following down ramping rates at IGD:
- When IGD flows are above 1750 cubic feet per
second (CFS)
: Decreases in flows of 300 CFS
or less per 24-hour period, and no more than 125
CFS per four-hour period.
- When IGD flows are 1,750 CFS or less:
Decreases in flows of 150 CFS or less per
24-hour period, and no more than 50 CFS per
two-hour period.
- The lake elevation operational criteria will
use a curve to transition from one end-of-month
elevation to the succeeding month, as described in
Attachment A. A similar curve for river flows is
still being developed for future use.
4. PROJECT WATER BANK FOR 2004:
- Beginning on April 1, and extending throughout
the irrigation season of each year, Reclamation
will release water bank water to supplement river
flows according to the flow schedule agreed upon
between NOAA Fisheries and Reclamation (Table 5).
As long as these releases, beginning on April 1
and continuing throughout the irrigation season,
comply with agreed-upon flow schedules, regardless
of whether spill conditions contributed to
achieving those flows, Reclamation will have
fulfilled its BO flow obligations. Reclamation
understands that NOAA Fisheries agrees to this
provision. If the water year type is changed, then
NOAA Fisheries and Reclamation will agree upon the
amount of the water bank water remaining in, or
estimated to accrue to, the water bank to use in a
revised augmented flow schedule appropriate for
the new water year type.
- The Project water bank will be 75,000
acre-feet. During 2004, Reclamation is pursuing
reasonable options for securing water to meet the
water bank requirement. Table 5 displays the flows
(CFS) at Iron Gate Dam (IGD) resulting from NOAA
Fisheries’ recommended distribution of the water
bank (75,000 acre-feet) during a BELOW AVERAGE
water year type (WYT):
Table 5. Recommended IGD Flows
Provided with Project Water Bank (BELOW AVERAGE)
|
"Below Average" WYT IGD Base
Flow
(Source-Table 4) |
Additional Flow Provided by
Water Bank |
NOAA Fisheries’
Recommended IGD Flow (using
Water Bank) |
Water Bank Amount used to
Provide Recommended Flow (acre-feet) |
April 1-8 |
1826 |
174 |
2000 |
2756 |
April 9-15 |
1826 |
0 |
1800 |
0 |
April 16-20 |
1431 |
319 |
1750 |
3164 |
April 21-26 |
1431 |
269 |
1700 |
2668 |
April 27-30 |
1431 |
219 |
1650 |
1738 |
May
1 |
1021 |
629 |
1650 |
1248 |
May
2-6 |
1021 |
579 |
1600 |
5742 |
May
7-11 |
1021 |
529 |
1550 |
5246 |
May
12-15 |
1021 |
479 |
1500 |
4750 |
May
16 |
1043 |
457 |
1500 |
906 |
May
17-21 |
1043 |
407 |
1450 |
4036 |
May
22-26 |
1043 |
357 |
1400 |
3541 |
May
27-31 |
1043 |
307 |
1350 |
3045 |
June
1-5 |
959 |
341 |
1300 |
3382 |
June
6-10 |
959 |
291 |
1250 |
2886 |
June
11-15 |
959 |
241 |
1200 |
2390 |
June
16-20 |
746 |
404 |
1150 |
4007 |
June
21-25 |
746 |
354 |
1100 |
3511 |
June
26-30 |
746 |
304 |
1050 |
3015 |
July
1-15 |
736 |
264 |
1000 |
7855 |
July
16-31 |
724 |
276 |
1000 |
8759 |
August 1-31 |
979 |
21 |
1000 |
1291 |
September 1-30 |
1168 |
0 |
1168 |
0 |
Total Water Bank Amount Used |
75,936 |
5. ESTIMATED PROJECT WATER SUPPLY FROM UKL FOR
IRRIGATION AND REFUGES DURING 2004:
Water Supply for Irrigation. The
estimated Project water supply (assuming a
BELOW AVERAGE water year type) for irrigation from
UKL from April 1 through September 30, 2004 is
335,000
acre-feet
based upon the hydrological conditions existing on
April 1. This may be reduced by the amount of
water acquired for the water bank through land
idling and groundwater substitution. This amount
may increase or decrease in response to
hydrological conditions after April 1 because
actual conditions may differ widely from those
assumed by the operation forecast model. Project
water deliveries after October 15, would be
contingent upon availability of water from UKL and
hydrological conditions from October 2004 through
March 2005.
- Water Supply for Refuges
.
The estimated amount of
Project water from UKL for delivery to national
wildlife refuges from April through October 2004
will be 25,000 acre-feet. This was
estimated in relation to historic deliveries to
refuges.
EAST SIDE DELIVERY AREA
ESTIMATED PROJECT WATER SUPPLY FOR THE EAST SIDE
DELIVERY AREA DURING 2004:
- The estimated Project water supply for
irrigation from Gerber Reservoir and Clear Lake
from April 1 through September 30, 2004 is
71,320 acre-feet. Table 6 displays the
projected elevations of Gerber Reservoir and Clear
Lake on April 1; the minimum elevations needed to
meet the biological requirements of endangered
suckers on September 30 (i.e. to provide adequate
over-wintering habitat for endangered suckers);
and the difference between the April 1 and
September 30 reservoir/lake capacities, minus
evaporation and seepage. The difference between
the reservoir/lake capacity on April 1 and
September 30 is the estimated Project water supply
for irrigation.
Table 6. Estimated Project Water
Supply for East Side Delivery Area
|
Projected
April 1
Elevation |
April 1
Capacity
(acre-feet) |
ESA Minimum
Sept 30
Elevation |
Sept 30
Capacity
(acre-feet) |
Apr 1-Sept 30
evap/seepage
(acre-feet) |
Net diff. between Apr. 1 and
Sept 30 capacities |
Gerber Reservoir |
4822.49 |
49,770 |
4798.1 |
1,300 |
6,400 (est) |
42,070 |
Clear Lake |
4526.24 |
130,400 |
4520.6 |
41,150 |
60,000 (est) |
28,250 |
Total amount of project water
available for East Side delivery area |
71,320 |
OTHER INFORMATION RELEVANT TO 2004 OPERATIONS
PLAN
COMPARISON OF ESTIMATED WATER SUPPLY TO HISTORIC
DELIVERY:
- The following comparison is provided for
information purposes only
and uses a BELOW
AVERAGE water year type for the UKL delivery area
(5 WYT) and a BELOW AVERAGE water year type for
the East Side delivery area (4 WYT). Table 7
compares the 2004 estimated Project water supply
for irrigation and refuges to historical
deliveries from 1961 to 2003.
Table 7. Comparison of Estimated
2004 Project Water Supply to Historic Deliveries
|
2004 Estimated Supply
(1000 acre-feet) |
Historic Delivery (1961-2003)
During BELOW AVERAGE
Water Year Types (1000
acre-feet) |
UKL Delivery Area
|
335.0 |
Ave = 299.0 (235.0 to 330.0) |
National Wildlife Refuges
|
25.0 |
Ave = 36.9 (16.3 to 58.1) |
East Side Delivery Area
|
71.3 |
Ave = 74.4 (56.5 to 89.5) |
ATTACHMENT A
Klamath Project - 2004 Operations
Plan
GENERAL DESCRIPTION OF 2004
OPERATIONS PLANNING PROCESS
The 2004 operations plan was developed in
accordance with the 2002 Service and NOAA
Fisheries biological opinions. The information in
the plan is developed as follows:
FOR THE UPPER KLAMATH LAKE (UKL) DELIVERY AREA:
1. ESTIMATE INFLOWS TO UKL:
- Reclamation estimates the inflow (in
acre-feet) using the NRCS forecast beginning in
early January (for information purposes) and
revises the inflow predictions in early February,
March and on April 1. The estimate of predicted
inflows uses the 50% exceedance for UKL for lake
elevation planning considerations and a 70%
exceedance for UKL river flow planning
considerations.
2. DETERMINE WATER YEAR TYPE FOR 2004:
- UKL water year types for Project operations
planning purposes are defined by historic, actual
inflow. The methodology used to define the water
year type parameters was explained in the
Klamath Project 1998 Operations Plan Environmental
Assessment. For UKL, water year type is
defined by the forecast inflow between April 1 and
September 30 annually. In early April (usually on
or after April 10), Reclamation will determine the
water year type most likely to occur from April
through September. As a result of ESA
consultation, two sets of water year types have
been defined for purposes of annual operations
planning. For lake elevation planning, Reclamation
will use four water year types: (1) above
average; (2) below average; (3) dry;
and (4) critical dry. For river flow
planning, Reclamation will use five water year
types: (1) wet; (2) above average;
(3) average; (4) below average and;
(5) dry. Reclamation will continue to
monitor the NRCS forecasts in May and June. After
June, actual inflow to UKL will be regularly
monitored. The continued monitoring of predicted
and actual inflows will allow Reclamation to adapt
Project operation to respond to the actual water
year type if precipitation and hydrological
conditions after April 1 vary significantly from
conditions prior to April 1. The water year type
can, and will, be changed to either wetter or
drier year types after April 1, if necessary, in
response to actual hydrologic conditions.
3. LAKE ELEVATION AND RIVER FLOW OPERATIONAL
CRITERIA FOR 2004:
- Water deliveries for irrigation from UKL will
be provided within the operations regime observed
from water year 1990 through water year 1999
(ten-year period) consistent with the findings of
the National Research Council’s Interim Report of
February 2002. The observed values for the lake
levels and river flows that occurred during the
ten-year period were used as criteria to determine
the Project’s irrigation and refuge deliveries in
Reclamation’s biological assessment (BA). The
operational criteria for river flows have been
revised to be consistent with the reasonable and
prudent alternative (RPA) in NOAA Fisheries 2002
biological opinion. That biological opinion
specifies that during Phase I (2002-2005)
Reclamation will operate the Project to meet or
exceed the Klamath River flows at Iron Gate Dam
described in Table 5.9 of the biological
assessment (as modified by conversion to five
water year types) plus the additional volume of
water to be provided by the water bank . It also
states that the flows would be modified on an
annual basis by agreed upon use of the water bank
for improved spring flows and/or summer flows and
that by March 31 of each year, NMFS and
Reclamation will determine how this additional
water will be distributed for release.
- The lake elevation and river flow operational
criteria specify certain elevations/flows at
certain time steps (end-of-month for lake
elevations and average monthly or semi-monthly for
river flows). During Project operations in 2002
and 2003, Reclamation found that transitioning
from one time step to the next succeeding step
resulted in abrupt changes in elevations/flows,
especially when the water year type was changed to
either a wetter or drier year types after April 1,
as described in No. 2 above. Such abrupt changes
were at times viewed as being adverse to the lake
or river resources. For 2004 operations,
Reclamation developed a curve, rather than abrupt
steps, to permit a smoother transition of lake
elevations from one time step to the next . The
curve was developed in consultation with the
Service, Tribes and water users. A similar curve
is being developed for river flows but will not
likely be available for use during 2004.
4. QUANTIFY THE PROJECT WATER BANK
REQUIREMENTS FOR 2004:
- Reclamation’s 2002 BA proposed establishment
and use of a "water bank" and that the size of the
water bank would be determined using criteria set
out in the 2002 BA. However, as a result of ESA
consultation, the Service and NOAA Fisheries
established the water bank size for 2004 at 75,000
acre-feet in the 2002 biological opinions (page 11
and page 56 in the respective opinions).
Therefore, the water bank size has been determined
and does not require the calculation as outlined
in the 2002 BA. Reclamation has agreed to operate
the Project during 2004 consistent with the 2002
biological opinions.
- During 2004, Reclamation will pursue
reasonable options for securing water to meet the
water bank requirement. Reclamation believes that
several sources of water, including regulatory
storage, forbearance of surface water use, and
groundwater may be feasible for the water bank.
Forbearance of surface water includes water used
for both irrigation and refuges. Forbearance of
irrigation use involves farmers voluntarily idling
their lands in return for compensation.
Groundwater or conjunctive use involves using
pumped groundwater from wells to supplement
surface water supplies. There may be additional
shortages to irrigation and refuge deliveries due
to hydrological conditions after the water bank is
deducted from the Project water supply.
Agricultural users would not be compensated for
these additional shortages that result from
unanticipated hydrologic conditions.
- The initial water year type for 2004 has been
determined to be BELOW AVERAGE and the
distribution of the water bank is shown in Table 5
of the 2004 Operations Plan. The following table
displays the water bank distribution, as agreed to
by NOAA Fisheries, if the water year type is
changed after April 1 to an AVERAGE water year
type:
Recommended IGD Flows Provided
with Project Water Bank (AVERAGE WYT)
|
"Average" WYT
IGD Base Flow
(Source-Table 4) |
Additional Flow Provided by
Water Bank |
NOAA Fisheries’
Recommended IGD Flow (using
Water Bank) |
Water Bank Amount used to
Provide Recommended Flow (acre-feet) |
April 1-15 |
1863 |
337 |
2200 |
10026 |
April 16-30 |
2791 |
0 |
2791 |
0 |
May
1-15 |
2784 |
0 |
2784 |
0 |
May
16-20 |
1466 |
1034 |
2500 |
10255 |
May
21-25 |
1466 |
734 |
2200 |
7279 |
May
26-30 |
1466 |
534 |
2000 |
5296 |
May
31 |
1466 |
334 |
1800 |
662 |
June
1-4 |
827 |
973 |
1800 |
7720 |
June
5 |
827 |
823 |
1650 |
1632 |
June
6-9 |
827 |
773 |
1600 |
6133 |
June
10 |
827 |
623 |
1450 |
1236 |
June
11-15 |
827 |
573 |
1400 |
5683 |
June
16-30 |
1163 |
137 |
1300 |
4076 |
July
1-15 |
756 |
244 |
1000 |
7260 |
July
16-31 |
735 |
265 |
1000 |
8410 |
August 1-31 |
1040 |
0 |
1040 |
0 |
September 1-30 |
1300 |
0 |
1300 |
0 |
Total Water Bank Amount Used |
75,668 |
Reclamation’s compliance with the biological
opinions requires a water bank which involves
acquiring water from all components of the
Project, including refuges. The water bank amount
has been established for 2004 (i.e. 75,000
acre-feet). The extent that the irrigation and
refuge components of the Project provide water for
the water bank will be based upon their Project
water use. This means that when Project irrigators
are required to reduce a portion of their Project
water use through forbearance, then Project water
deliveries to refuges would be reduced by a
similar proportion.
5. ESTIMATE PROJECT WATER SUPPLY FOR
IRRIGATION AND REFUGES FOR 2004:
Reclamation estimated the Project water supply
for irrigation and refuges available from the
Klamath River upstream from Keno Dam by:
- First, estimating inflow from April 1 through
September 30, 2004.
- Second, determining the applicable water year
type for 2004.
- Third, quantifying the applicable water bank
amount for 2004.
- Fourth, determining the minimum historic
amount of water for agriculture based on the year
type:
- Fifth, using the elevation/flow operational
criteria for the applicable water year type.
- Last, estimating the available Project water
supply, after deducting the water bank amount,
using the KPOPFOR forecasting model that may be
available, keeping in mind that actual conditions
may differ significantly from the model.
6. REFUGE WATER SUPPLY:
- Project water has historically been delivered
to Tule Lake and Lower Klamath National Wildlife
Refuges during Project operation (see Table 7) for
maintaining seasonal and permanent refuge
wetlands. Reclamation considered historic refuge
deliveries to assist with 2004 operations
planning. The Service provided information related
to refuge management and operation during various
water year types. The refuges receive water
year-round, not just during April-September.
October-March water deliveries are important to
the refuge and affect overall Project operation.
Reclamation may be required to adjust refuge
Project water deliveries to meet the 2002
biological opinion requirements and irrigation
deliveries, when necessary. Should additional
requirements for Project water develop then
Project water deliveries to refuges could be
further reduced. If additional hydrologic
shortages occur, refuge deliveries could be
completely curtailed.
- Reclamation stated in its 2002 BA that
national wildlife refuges, including Tule Lake,
Lower Klamath, Upper Klamath Lake and Clear Lake
Refuges, are under the jurisdiction of the Service
and their operation is subject to the Service’s
management and control. The BA described only
those effects on the refuges that resulted from
operation of the Klamath Project and not the
effects of refuge operation. During 2004,
Reclamation will operate the Project consistent
with the requirements of the 2002 biological
opinions, including establishment/use of a water
bank, and provide adequate water to Lower Klamath
and Tule Lake National Wildlife Refuges, when in
priority and when water is available. This
requires consideration of refuge water deliveries
as part of the 2004 operations plan because those
deliveries contribute to Reclamation’s ability to
meet the biological opinion requirements and its
legal obligations.
7. OTHER INFORMATION RELEVANT TO THE
OPERATIONS PLAN:
Reclamation considered other information relevant
to the operations plan that could influence the UKL
Project water supply for irrigation and refuges,
such as:
- Comparing the estimated 2004 Project water
supply for the UKL delivery area to historic UKL
irrigation and refuge deliveries, and comparing
the estimated 2004 Project water supply for the
East Side delivery area to historic East Side
irrigation deliveries. The comparison of estimated
supplies to historic deliveries serves to inform
both Reclamation and Project water users of
potential needs for additional demand
reduction/supply enhancement measures. Reclamation
may investigate and implement measures to either
further reduce demand or enhance supply as a
result of the comparison, if needed. Such measures
would be in addition those implemented to
establish the water bank.
- Reclamation considered the effects of
pre-season fall/winter irrigation of agricultural
and lease lands in the UKL delivery area. This
pre-irrigation could, during drier hydrologic
conditions, affect Reclamation’s ability to meet
the UKL operational criteria for endangered
suckers by reducing the amount of water storage in
the lake. If such a circumstance were to arise,
then Project operation could be modified in
response to pre-season irrigation and/or the
available supply for pre-irrigation could be
reduced. This condition did not occur prior to
April 1, 2004.
- Precipitation in Klamath Falls, Oregon during
February and March establishes the agricultural
demand index when the irrigation season starts in
early April. This index is integrated into
operation planning model used to predict the
Project water supply.
FOR THE EAST SIDE DELIVERY AREA:
ESTIMATED PROJECT WATER SUPPLY FOR THE EAST SIDE
DELIVERY AREA DURING 2004:
- Reclamation will operate the Project
reservoirs that serve the East Side delivery area
(Gerber Reservoir and Clear Lake) consistent with
the 2002 biological opinions, as amended to
clarify application of the operational criteria
for endangered suckers. This operation ensures
that reservoir/lake elevations do not recede lower
than the minimum elevations needed to protect
endangered suckers on September 30, i.e.
elevations 4798.1 for Gerber Reservoir and 4520.6
for Clear Lake. Reclamation estimated the Project
water supply for irrigation by: (1) determining
the April 1 reservoir/lake volume (assuming that
the April 1 elevation is no less than the minimum
required elevation to protect endangered suckers);
(2) adding any inflows and subtracting
evaporation/leakage between April 1 and September
30; and (3) subtracting the September 30
reservoir/lake volume at the minimum required
elevations to protect endangered suckers.
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