Quarterly Water Supply Strategy and
Budget Report
California-American Water, Water
Distribution System: July – September 2006
June
22, 2006
1. Management
Objectives
The
District desires to maximize the long-term production potential and protect the
environmental quality of the
2. Quarterly
Water Supply Strategy: April - June 2006
On
June 6, 2006, staff from the District, Cal-Am, and NOAA Fisheries discussed the
proposed water supply strategy and related topics for the remainder of June 2006
and the July-September 2006 period.
Currently, Los Padres Reservoir is full and spilling,
Given
these “above normal” hydrologic conditions, it was agreed that for the
remainder of June, Cal-Am's diversions from the upper Carmel Valley would be up
to 1.5 cubic feet per second (cfs), including combined production from the
Russell Wells Nos. 2 and 4 and other sources upstream of and including Scarlett
Well No. 8. If feasible, Cal-Am could
divert water from its San Clemente Reservoir during this period. However, the
feasibility of diverting water at San Clemente Dam is constrained by water
quality and operations related to the San Clemente Reservoir Drawdown Project
mandated by the Department of Water Resources (DWR). The proposed budget limits Cal-Am diversions
to 0.5 cfs upstream of and including Scarlett Well No. 8, when the streamflow
recedes to 20 cfs for five consecutive days at the MPWMD gaging station at
For
the
Based
on the rainfall and runoff that occurred during the October-May 2006 period, it
was agreed that the projections for the upcoming quarter should be based on the
assumption that inflows will range into “wet
and extremely-wet year” levels during the budgeted June through September 2006
period. Specifically, the projected daily flows for this period were based on the
reconstructed record of unimpaired flows at San Clemente Dam during WY 1982,
adjusted for differences in timing of the actual recession in WY 2006. Building
on similar forecasts made for the 2006 Memorandum of Agreement, District staff
projected monthly unimpaired inflows at San Clemente Dam of 3,382, 1,520, 651
and 315 AF for the months of June, July, August, and September 2006,
respectively. These monthly inflows are approximately equal to the 12-25% exceedance
levels for these months, based on the 1902-2004 period of record. Table 1 shows a monthly breakdown of the
recommended diversion and release schedule under the projected inflow
conditions. Table 1 also shows
expected inflows, outflows, and storage volumes at Los Padres and San Clemente
Reservoirs for the July-September 2006 period.
It should be noted that there is some uncertainty regarding the runoff that will occur during the upcoming quarter and this uncertainty is compounded by the situation at San Clemente Dam and Reservoir, where Cal-Am is required to draw down San Clemente Dam. Based on the 2006 Biological Opinion for the Interim San Clemente Reservoir Drawdown Project by the NMFS and staff’s most recent projection of the daily flow recession, Cal-Am is likely to operate San Clemente Dam as follows:
1) With fish
trapping scheduled to begin on June 28, 2006, the reservoir will remain full at
the spillway elevation of 525 feet through July 2, 2006.
2) Drawdown of the reservoir from
elevation 525 to 515 feet will commence on July 3, 2006.
3) During the drawdown period from July 3 to approximately August 4, 2006, the reservoir releases may be modified, depending on the physical ability to release water while minimizing the turbidity of water released through the ports or any other passage.
U:\staff\word\boardpacket\2006\2006boardpackets\20060622\PubHrgs\20\item20_exh20b.doc
[1] Limiting diversions to 0.5 cfs upstream
of Scarlett Well No. 8 is consistent with SWRCB Water Rights Order WR 2002-0002
and the 2002 Conservation Agreement between Cal-Am and the National Marine
Fisheries Service.