ITEM:

ACTION ITEMS

 

17.

RECEIVE AND CONFIRM WATER SUPPLY FORECAST FOR PERIOD OF MAY 1, 2009 THROUGH SEPTEMBER 30, 2010

 

Meeting Date:

May 21, 2009

Budgeted: 

N/A

 

From:

Darby Fuerst,

Program/

N/A

 

General Manager

Line Item No.:

 

Prepared By:

Darby Fuerst

 Cost Estimate: 

N/A

 

General Counsel Approval:  N/A

Committee Recommendation:  N/A

CEQA Compliance:  N/A

 

SUMMARY:  Regulation X of the Monterey Peninsula Water Management District (District) Rules and Regulations requires that a water supply summary forecast report be compiled annually to analyze the status of water supply and demand within the District.  This report quantifies rainfall, runoff, and storage conditions within the District as of May 1, 2009, and forecasts the amount of water that will be available for use during the upcoming water year. 

 

Physical Water Availability:  As of May 1, 2009, usable water storage within the Monterey Peninsula Water Resource System (MPWRS) totaled 30,900 acre-feet or 82% of maximum storage capacity.  A map of the MPWRS is included as Exhibit 17-A.  A breakdown of total storage by reservoir and aquifer is shown in Exhibit 17-B.  As shown, usable reservoir storage totals 1,700 acre-feet and usable aquifer storage totals 29,200 acre-feet.  In addition, a summary of other water-supply related conditions within the MPWRS -- rainfall, runoff, and number of adult steelhead recorded at San Clemente Dam, and California American Water (Cal-Am) monthly diversions from the Carmel River and Seaside Groundwater Basins relative to limits set by the State Water Resources Control Board (SWRCB) and Court -- are shown in Exhibit 17-C and 17-D.

 

The amount of carryover storage that is needed to meet the projected water needs within the District for the remainder of Water Year (WY) 2009 and all of WY 2010 is shown in Exhibit 17-E.  These projections include the water needs of both Cal-Am customers and non Cal-Am water users within the District who rely on water from the MPWRS.  As shown, the projected water demand for the remainder of WY 2009 is 9,423 acre-feet.  Similarly, the projected demand for WY 2010 is 17,793 acre-feet. This projection is based on the maximum annual production amount for the Cal-Am main system from the Carmel River Basin directed by the SWRCB in Order No. WR 95-10 (11,285 acre-feet), the maximum annual production amount for Cal-Am from the Seaside Groundwater Basin specified by the Court as a result of the Seaside Basin adjudication and amended by the Seaside Watermaster on May 7, 2009 (3,462 acre-feet), and the maximum production amount for non Cal-Am users in the MPWRS specified in the District’s Water Allocation Program (3,046 acre-feet).

 

As shown in Exhibit 17-E, the total amount of water needed to meet the projected water demand for the remainder of WY 2009 and all of WY 2010 is 27,216 acre-feet.  Given the current usable storage estimate of 30,900 acre-feet, there is sufficient stored water in the MPWRS to meet the projected water needs for the remainder of WY 2009 and begin WY 2010 with a full year’s supply in reserve.  This is consistent with the District drought protection goal approved by the Board in August 1993.

 

It should also be noted that this approach is conservative in that it is based entirely on storage and does not include any allowance for surface and subsurface inflows that are expected to occur.  Therefore, based on the physical availability of water, no mandatory water demand reductions, i.e., rationing actions, are required at this time.  It should be noted, however, that this analysis does not incorporate environmental considerations such as effects on riparian and aquatic resources.

 

Community Water Demand:   For WY 2009, as of May 1, 2009, Cal-Am had produced 6,780 acre-feet of water from its sources in the MPWRS to serve its customers. This amount of production is 460 acre-feet under the year-to-date at month-end production target (7,240 acre-feet) that had been set for Cal-Am based on SWRCB Order 95-10 and the Seaside Groundwater Basin adjudication decision. 

 

Seaside Groundwater Basin Yield:   It should be noted that this forecast is based on an assumption that Cal-Am can produce up to 14,747 acre-feet each year from its sources in the MPWRS to serve its customers.  This limit is based on the maximum amount that Cal-Am is allowed to produce from the Carmel River Basin (11,285 acre-feet per year) under SWRCB Order 95-10 and the maximum amounts that Cal-Am has been allocated to produce from the Coastal Subareas (3,191 acre-feet) and from the Laguna Seca Subarea (271 acre-feet) of the Seaside Groundwater Basin in the Seaside Basin adjudication (California American Water v. City of Seaside, Monterey County Superior Court No. M 66343).

 

RECOMMENDATION:   The Board should receive the water supply forecast for the May 1, 2009 through September 30, 2010 period. 

 

IMPACTS ON STAFF/RESOURCES:  District staff currently tracks and reports on water production and water supply conditions on a monthly basis; no additional impacts are anticipated related to this item.

 

EXHIBITS

17-A    Map of the MPWRS

17-B    MPWRS Water Storage Conditions

17-C    MPWMD Water Supply Status -- May 1, 2009

17-D    Monthly Cal-Am Diversions from Carmel River and Seaside Groundwater Basins

17-E    Derivation of Water Rationing Triggers for the MPWRS for WY 2009

 

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