Final Report, 2010 Urban Water Management Plan - Culver City

• 1999 Water Surplus and Drought Management Plan (WSDM): The WSDM provides thepolicy guidance to manage the region’s water supplies to achieve the reliability goals of theIRP. This is achieved by integrating the operating activities of surplus and shortage suppliesthrough a series of stages and principles.• 2008 Water Supply Allocation Plan (WSAP): The WSAP includes the specific formula forcalculating member agency supply allocations and the key implementation elements neededfor administering the allocation. The need for the WSAP arose after the 2008 Bay-Deltabiological opinions and rulings that limited SWP supplies to its contractors includingMetropolitan. The WSAP formula seeks to balance the impacts of a shortage at the retaillevel while maintaining equity on the wholesale level for shortages of Metropolitan suppliesup to 50 percent.Since the 2008 Bay-Delta reductions, Metropolitan has been using the WSAP formulas tocontend with the reduction in available imported supplies implementing a Stage 2 (Regional10 percent reduction in supply allocation) of the WSAP from July 2009 to April 2011. Duringsuch allocations, Metropolitan institutes severe financial penalties should an entity requestsupply over their reduced allocation. This in effect, limits supply at the retail level. Although itis anticipated that the WSAP will continue to be in effect in the near–term, Metropolitanstates in its 2010 Draft UWMP that there will be sufficient supply to meet member agencydemands in single and multiple-dry years from 2015 through 2035. However, this isassuming that Metropolitan storage levels are at or above average levels prior to thosecycles, and key programs come to fruition as assumed by Metropolitan in their projections.For example, Metropolitan assumes that a Delta conveyance solution will be in place by2022. Also, Metropolitan has indicated that there is a 50 percent probability that storagelevels will be lower than the assumption used. Based on the recent WSAP allocations andregulatory restrictions in the Delta, GSWC’s conservative assumption is that Metropolitan’sprojections in their 2010 Draft UWMP may not be 100 percent reliable in all cases.6.1.1.2 WBMWD Supply ReliabilityWBMWD expects its supplies to be 100 percent reliable through 2035 for normal, single andmultiple-dry year scenarios. WBMWD’s plan for reliability focuses on water resourcediversification. WBMWD’s Draft 2010 UWMP documents a planned shift from a 62 percentdependence on Metropolitan imported water to 36 percent of overall supply coming fromMetropolitan by 2030 as shown in Table 6-1. This would be accomplished by employing adiversified water resources portfolio incorporating increased supply from recycled water,desalination, and conservation-derived supply initiatives.Table 6-1:WBMWD Service Area Projected Water Supply Percent by CategorySupply Source 2010 Percent of Supply 2030 Percent of SupplyConservation-derived supply 8% 11%Recycled Water 8% 19%Imported Water (Metropolitan) 62% 36%Groundwater 22% 23%Desalination 0% 11%Note:West Basin Municipal Water District 2010 Draft Urban Water Management PlanFinal Report, 2010 Urban Water Management Plan – Culver City Page 6-3Golden State Water Companyg:\adminasst\jobs\2010\1070001.00_gswc-uwmp\09-reports\9.09-reports\2011-08\grp3\gswc_culvercity_2010_uwmp-final.doc