Pictured above is the U.S. EPA 'Surf your Watershed' site’s display of the six watersheds of Alameda County.

‘Surf your Watershed’ is an excellent tool from the U.S. Environmental Protection Agency that helps you find basic data on all the watersheds in your county. The site includes U.S. Geologic Survey data, water quality information, and links to local citizen’s groups working on water stewarship, clean up and other  issues (39 in Alameda County!)

Check it out