Guide to San Francisco Bay Area Creeks
San Francisco Watershed Finder
The southeastern portion of San Francisco is mostly bedrock and alluvial soil. This area was dominated by the watersheds of two large creeks, Mission Creek and Islais Creek.
The Richmond, Sunset, Western Addition, and Financial Districts of San Francisco were largely lacking in creeks. In these areas isolated bedrock hills poked through a blanket of
sand dunes. Rainwater soaked into the permeable soils. Today most runoff is collected by the combined sewers, conveying both rain water and wastewater
to treatment plants. The modern watersheds shown here are defined by the sewer networks and high-flow discharge points.
Click on map for detailed watershed maps