Reservoir and redirecting that 2,400 AFY to Brisbane through its regional water system. The SFPUC evaluated the effects of increasing diversions from the Tuolumne River and, in turn, reducing flow releases from Hetch Hetchy Reservoir on the Tuolumne River and its resources in the program EIR it prepared on its Water System Improvement Program (WSIP) (San Francisco Planning Department, 2008). This program EIR is incorporated by reference and is available for review on the San Francisco Planning Department website (http://www.sf-planning.org/index.aspx?page=1829) and also at the City of Brisbane Planning Department during regular business hours.

The WSIP Program EIR evaluated the impacts of a range of possible additional diversions from the Tuolumne River from 2 mgd to 24 mgd. As described and analyzed in the WSIP Program EIR (Volume 7a, page 13-8, Table 13.2, and Volume 8, Appendix O-3), the adopted WSIP would result in an increase in average annual diversions of 2 mgd from the Tuolumne River over existing conditions in the area along the Tuolumne River between Hetch Hetchy and Don Pedro Reservoirs. The WSIP Program EIR described and analyzed impacts on the following potentially affected resources (see Program EIR Volume 3, Section 5.3, and Volume 7a, Sections 14.5, 14.6, and 14.7): stream flow and reservoir water levels, geomorphology, surface water quality, surface water supplies, groundwater, fisheries, terrestrial biological resources, recreational and visual resources, and energy resources. With one exception, the WSIP Program EIR determined that impacts of the adopted WSIP—including the MID water transfer—on potentially affected resources in the Tuolumne River watershed and downstream water bodies would be less than significant, and no mitigation measures would be required. The one exception is that the WSIP Program EIR identified potentially significant—but mitigable—impacts on terrestrial biological resources in the Tuolumne River watershed due to an increase in average annual diversions from the Tuolumne River and the associated modifications in releases from Hetch Hetchy Reservoir. This impact was identified for the reach of the river between Hetch Hetchy Reservoir (O’Shaughnessy Dam) and Don Pedro Reservoir, with particular impact on meadow and alluvial features in this reach, including the Poopenaut Valley. The impact on meadow and alluvial features would occur under a range of diversion increases, from the 2 mgd of the adopted WSIP up through the 30-mgd diversion increase proposed under the original WSIP project. The impact would result from both the increase in diversion as well as the changes in system operations adopted as part of the WSIP.

The proposed water transfer agreement would contribute to this potential impact on the Tuolumne River associated with changes in the SFPUC’s existing reservoir release pattern from Hetch Hetchy Reservoir that, in some years, could lead to flow changes that could adversely affect streamside meadows and other alluvial deposits. The SFPUC is implementing adopted WSIP Program EIR mitigation in order to reduce potential impacts on the streamside meadows and other alluvial deposits along the Tuolumne River below this reservoir to less-than-significant levels. The SFPUC’s mitigation action will, in effect, address this impact and remedy it such that it would not continue to be an impact for water transfers such as is proposed between OID and Brisbane for the Baylands.