How is the Region Defined?

The specific geographic extent of the Bay Area IRWMP is based on the boundary of the San Francisco Bay Regional Water Quality Control Board (Region 2). This boundary was selected for two primary reasons: hydrology and jurisdictions. Hydrologically, the Region 2 boundary generally represents the watershed interfluve for Bay-draining surface flows and runoff. Although some coastal Marin, San Francisco, and San Mateo County lands are included within the Region 2 boundary, a majority of lands drain to the Bay. For the purposes of developing a plan to manage integrated water resources, using a physically based watershed boundary that drains (a majority of) lands to a common receiving water body (the Bay) is advantageous. Additionally, Region 2 is a historically defined jurisdictional boundary. Using a well-understood and existing jurisdictional boundary reduces confusion for participating agencies who are already familiar with its geography.

In addition, the Coordinating Committee (CC) has organized the region into subregions. These subregions are explained in the "Regional Acceptance Process (RAP) Submittal" document with a map showing the subregions on page 3-29 (pdf page 51). Each region is represented on the CC, and because of their uniqueness, have their own organizational structure. The RAP document has the most current definition and explanation of the region.