Related Links April 2008 Water Supply Outlook Letter from the Governor (PDF file, 1.22 MB) July 2007 Water Supply Outlook MWD Water Surplus and Drought Management Plan Report (January 7, 2008) (Powerpoint file, 411 K) WATER CONDITIONS: Tight Supply from Colorado River Could Hike Water Rates Memorandum: Colorado River Board of California (Word document, 39K)

WATER SUPPLY OUTLOOK FOR MAY 2008

Metropolitan Prepares to Call Water Supply Alert

At its May meeting, the Board of Directors of the Metropolitan Water District directed staff to draft a resolution calling for a Water Supply Alert to be considered by the Metropolitan Board at its upcoming June meeting.  The proposed Water Supply Alert would call upon Southern California's cities, counties, member agencies and retail water agencies to take immediate steps to reduce near-term water use. The resolution is also intended to draw public attention to the urgent need for conservation, consistent with Metropolitan's conservation outreach program.

The Water Supply Alert is part of a larger call for extraordinary conservation measures for the remainder of calendar year 2008.  The proposed measures include a broad set of potential near- and long-term water use efficiency actions intended to reduce demands throughout Metropolitan's service area in order to preserve the region's dry-year supply reserves. Actions taken in 2008 to preserve reserve supplies could avoid or reduce the magnitude of potential supply allocations under Metropolitan's Supply Allocation Plan in 2009 or 2010 if the current water supply conditions persist.

As shown in the diagram below, the implementation of extraordinary conservation measures is called for under the "severe shortage" stages within Metropolitan's Water Surplus and Drought Management Plan.  Metropolitan continues to work to avoid implementing a supply allocation in 2008, despite ongoing dry conditions and restrictions in State Water Project pumping.

                      Metropolitan's Water Surplus and Drought Management Plan

Water Supply Conditions

The following is a summary of water supply conditions for the State of California and the Metropolitan service area.

Precipitation Conditions as of May 6, 2008

*     DWR Northern Sierra 8-Station Precipitation Index
**   DWR Bulletin 120 – May 1, 2008

Key Storage Conditions as of April 30, 2008

Summary of Hydrologic Conditions in California

The spring of 2008 is turning out to be extremely dry as two consecutive months of record low precipitation have taken their toll on spring runoff.  For the DWR's Northern Sierra 8-Station Precipitation Index, the combined March and April total precipitation was only 2.3 inches, the driest combined total on record (since 1921).  The 8-Station Index monitors rainfall in the northern Sierra Nevada and Shasta regions that feed into the Sacramento River system - the primary source of SWP supplies.  Since the beginning of the 2008 Water Year in October, the 8-Station Index seasonal total of 33.7 inches is 22nd driest year out of 88 years of record and is now less than last year's seasonal total of 35.5 inches at this time.  The March precipitation total of 1.6 inches (23% of average) was the sixth driest March on record. Statewide, March precipitation was about 20% of average.

Statewide hydrologic conditions as of May 1 were as follows: precipitation - 85 percent of average to date; runoff - 55 percent of average to date; and reservoir storage - 85 percent of average for the date. Statewide forecasts of snowmelt runoff have been significantly reduced by the dry spring, but are still better than last year and are forecasted to be about 60 percent of average. Reservoir storage on May 1 was about 85 percent of average, the lowest since 1994.  Last year May 1 storage was 105 percent of average. About 60 percent of total capacity was being used.  Snowpack water content is about 65 percent of average for the date and about 50 percent of the average on April 1, the date of normal maximum accumulation. This represents a loss of half the measured water content since April 1. Last year the snowpack on May 1 was only 25 percent of average.

The latest National Weather Service Climate Prediction Center (CPC) long-range weather outlook for May 2008 is forecasting below average precipitation for Northern and Southern California and average precipitation for Central California.

Metropolitan Water Surplus and Drought Management (WSDM) Plan Update

Current 2008 projections show that Metropolitan will have a need for over 660 TAF of supplies from WSDM Actions to meet firm, non-interruptible demands. This is based on the following assumptions:

• Range of Demands and Obligations - 1.9 to 2.3 MAF,
• Current Trend Demands and Obligations are 2.18 MAF
• The range of projected actual water sales is 1.9 to 2.2 MAF
  
  
• Colorado River Aqueduct Core Supplies - ≈ 800 TAF
• Basic Apportionment (550,000 AF)
• IID conservation program (85,000 AF)
• IID/SDCWA Transfer (50,000 AF)
• PVID Land Management Program (82,000 AF)
• Additional PVID Fallowing (20,000 AF)
  
  
• State Water Project Supplies - ≈ 750 TAF
• The SWP allocation remains at 35%
  
  
• Replenishment Deliveries Cuts of 100%
• IAWP delivery Cuts of 30%

At the beginning of CY 2008, Metropolitan had approximately 1.72 MAF of storage in its WSDM resource portfolio to manage base supplies and demands. Currently, the WSDM supplies and management actions available for CY 2008 are approximately 750 TAF.  Based on current trend demands, there is a need for approximately 660 TAF to meet base demands.  These demands are projected to be met through:

• Spot Market Water Transfers
  • In April, the Metropolitan Board approved the purchase of up to 54,000 acre-feet of north of Delta agricultural supplies – after accounting for Delta conveyance losses of 20 percent – at approximately $250/acre-foot, not including energy costs to deliver the water to Metropolitan's service area
    
    
• Maximizing Groundwater Production
• Local Groundwater production is expected to be roughly 70 TAF in 2008
  
  
• Withdrawals from Surface Storage and Dry-Year Groundwater Programs
• Withdrawals from the Central Valley (Semitropic, Arvin-Edison and Kern Delta) and southern California (Mojave and San Bernardino) groundwater storage programs were approximately 110 TAF in the first 3 months of 2008
• Additionally, 25 TAF from the 1992 Central Arizona groundwater storage program
• Metropolitan has access to over 400 TAF of surface storage from DVL, Castaic Lake and Lake Perris in CY 2008
  
  
• Extraordinary Conservation Measures
  • Staff presented its proposed extraordinary conservation measures at Metropolitan's May Board meeting.

Water Supply Outlook for April 2008

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