The San Pablo Bay Watershed encompasses approximately 1,575 square miles in Northern California. It is fed by several main rivers, including the Napa, Petaluma, and Sonoma, and receives a significant amount of precipitation from winter storms. The watershed also has a unique microclimate that supports a diverse array of flora and fauna. In terms of hydrology, the San Pablo Bay Watershed is highly influenced by the San Francisco Bay, which serves as its outlet to the Pacific Ocean. The watershed's surface water is also impacted by agricultural and urban runoff, as well as wastewater treatment plants. Snowpack is not a significant factor in the San Pablo Bay Watershed due to its location in a temperate coastal climate. The watershed contains several reservoirs, including Lake Berryessa and Lake Sonoma, which provide drinking water and flood control. The largest reservoir, Lake Berryessa, is also a popular recreational area for boating and fishing. Interesting climatic facts and trends include rising average temperatures and declining precipitation in recent years, which can impact water availability and the health of the watershed's ecosystems. The region also experiences periodic droughts and flooding events.