Quarterly Water Supply Strategy and
Budget Report
California American Water, Water
Distribution System: October – December 2005
September 19, 2005
1. Management
Objectives
The
District desires to maximize the long-term production potential and protect the
environmental quality of the Carmel River and Seaside Ground Water Basins. In addition, the District desires to maximize
the amount of water that can be diverted from the Carmel River Basin and
injected into the Seaside Ground Water Basin while complying with the instream
flow requirements recommended by the National Marine Fisheries Service (NMFS)
to protect the Carmel River steelhead population. To accomplish these goals, a water supply
strategy and budget for production within the California American Water (Cal-Am)
water distribution system is reviewed quarterly to determine the optimal
strategy for operations, given the current hydrologic and system conditions.
2. Quarterly
Water Supply Strategy: October – December 2005
On
September 7, 2005, staff from the District, Cal-Am, California Department of
Fish and Game (CDFG), and NMFS discussed the proposed water supply strategy and
related topics for the remainder of September 2005 and the October – December
2005 period. As of August 31, 2005, Los
Padres Reservoir was drawn down to elevation 1,029 feet with 1,101 AF of
storage, the Carmel River unimpaired inflow at San Clemente Dam was
approximately 6 cubic feet per second (cfs), and the drying riverfront was
located at Cal-Am’s Cypress Well at River Mile 5.4 (RM 5.4).
Based
on the runoff that has occurred since the beginning of WY 2005 and the higher
than expected flows since April 2005, the group agreed to set the projected
unimpaired monthly flows at San Clemente Dam for October, November and December
to above normal levels, which are equivalent to flows that have been exceeded
25-38% of the time during the historical record (1958-2004). Staff reviewed the likely inflow to date
through September 2005, and decided that slightly higher inflow levels are justified
for the remainder of September. Accordingly,
Table 1 shows a monthly breakdown
of the diversion and release schedule based on the assumption that unimpaired
inflows at San Clemente Dam will equal 243 Acre-Feet (AF) in September, 483 AF
in October, 1,155 AF in November and 3,630 AF in December. Table 1 shows expected inflows, outflows,
and storage volumes at Los Padres and San Clemente Reservoirs for the
October-December 2005 period. For this
analysis, it was assumed that Cal-Am would not directly divert water from San
Clemente Reservoir to the Carmel Valley Filter Plant, consistent with the 4d
rules adopted by the NMFS to protect steelhead, State Water Resources Control
Board Water Order WRO 2002-0002 and the Conservation Agreement between NMFS and
Cal-Am, which governs diversions during the low-flow period.[1]
The diversion and release rates specified for the October-December 2005
Water Supply Strategy and Budget are consistent with the terms and assumed
inflow conditions in the 2005 MOA between Cal-Am, CDFG and the District, but
the releases from Los Padres Reservoir are higher than the minimums required
under the 2005 MOA. During October and
November 2005, actual inflows may be significantly more or less than projected.
If so, the group will reconvene and adjust the release rates accordingly.
For
the Seaside Basin, it was agreed that in the October-December 2005 quarter,
Cal-Am will produce a total of 1,268 AF, with 468 AF in October, 450 AF in
November and 350 AF in December. These levels will help to conserve aquatic
habitats in the Carmel River and constrain annual withdrawals from the Seaside
Basin, and represent a 6 % reduction in production from previous years. In
conformance with the District’s temporary water appropriations permit to divert
water and inject it into the Seaside Basin, it is assumed that no water will be
diverted and injected during the October – December 2005 period.
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9/15/2005 1:19 PM
[1]
The
low-flow period is defined as times when streamflow in the Carmel River at the
MPWMD gage at Don Juan Bridge is less than 20 cfs for five consecutive days,
which occurred on July 20, 2005. Based
on projected inflows, streamflow is expected to be less than the 20 cfs
threshold in October and November. In December, inflows may increase above the
threshold, but the timing of this event and the continuance of the 2005 San
Clemente Interim Drawdown Project into December may preclude any significant
change in operations.