final Water Supply and Conveyance Agreements between Brisbane, OID, MID, and the SFPUC for various portions of the proposed water transfer. These Water Supply and Conveyance Agreements will contain provisions stating that the delivery of water from OID through MID and the SFPUC to Brisbane will not be permitted to impair the ability of MID or the SFPUC to deliver water to their existing customers.

During drought periods, MID and the SFPUC would continue to operate their systems in accordance with their own drought allocation policies and to comply with applicable regulations requiring diversion curtailments. The transfer of OID water through MID and the SFPUC would not alter drought year allocation or system management for their respective customers. The OID transfer to Brisbane does not involve the MID or SFPUC water supply and thus would not reduce available supplies to MID or SFPUC customers during drought (or non-drought) periods; the transfer only makes use of their water conveyance infrastructure. The transfer of this water through the MID and SFPUC water systems would not be permitted to affect the delivery capability or reliability for MID or SFPUC customers. No MID or SFPUC supply would be used to make up for any losses affecting the OID transfer water amount.

Water demand conservation measures mandated by the SFPUC throughout its service area and the aggressive water conservation measures of the Specific Plan (including an onsite recycled water plant), as stated on pages 4.O-3 to 4.O-4 and 4.O-29 to 4.O-31, respectively, would effectively reduce water demands for the Project Site development during periods of drought. Finally, the Draft EIR considered the water use of the Project Site development during periods of multiple dry year conditions with the Project Site development water savings program and concluded that sufficient firm water supply would be available for Project Site development under all four scenarios.

Water supply agencies throughout California are evaluating the potential effects of climate change on their supply sources. The SFPUC, the wholesale water supplier to the Bay Area peninsula communities that supplies most of Brisbane’s water, has been a leader in assessing climate change affects. As reported in the SFPUC 2010 Urban Water Management Plan (SFPUC 2011, Chapter 7 – Climate Change, p 91.), the SFPUC has conducted a detailed review of the current scientific literature regarding climate change and potential effects on water supply resources and identified several anticipated trends including reductions in average annual snowpack, a shift in snowmelt runoff to earlier in the year, changes in timing, intensity, and variability of precipitation, and an increased amount of precipitation falling as rain instead of snow. The SFPUC report notes that while general trends have been identified, “there is no clear scientific consensus on exactly how global warming will quantitatively affect the state’s water supplies, and current models of State water systems generally do not reflect the potential effects of global warming.” (SFPUC 2011)

The SFPUC conducted its own initial technical assessment of the potential effects of climate change on its Regional Water System and found that through 2025 a projected temperature increase of 1.5 degrees Celsius would result in about 7 percent of the runoff that now drains into Hetch Hetchy Reservoir shifting from the spring/summer season to the fall/winter season. The