Item #6b 1 Towards a Bay Area Watershed Model Presented to the SPLWG May 14, 2008 John Oram & Lester McKee

Item #6b 2 Objectives To improve understanding of both gauged and un-gauged streams throughout the Bay Area To improve estimates of water, sediment, and contaminant loads to the Bay from local watersheds

Item #6b 3 Previous / Ongoing Studies Bay Area Hydrology Model (BAHM) –Focus: hydrograph modification effects of land development projects –Extent: counties of Alameda, San Mateo and Santa Clara. –Model: HSPF –Usability: documented and downloadable Brake Pad Partnership (BPP) –Focus: estimate Cu loads to Bay –Extent: watersheds discharging to Bay –Model: HSPF –Usability: well-documented, not available

Item #6b 4 Where to go from here? Should we: –Develop a Bay Area-wide hydrologic model of our own? Could potentially build on BAHM and/or BPP –Continue current path of modeling well- studied watersheds (e.g., Guadalupe) and adding additional models incrementally? Candidates are Z4LA, Coyote Creek, Napa, Sonoma