High Quality Content by WIKIPEDIA articles! The Guadalupe Watershed consists of 170 square miles (400 km2) of land within northern California`s Santa Clara County. This watershed is owned and managed by the Santa Clara Valley Water District. The surface runoff from this area drains into the various rivers (namely the Guadalupe), streams, reservoirs or other bodies of water which all eventually gets carried into the San Francisco Bay (indicated below, with surrounding counties in red). Essentially, all the water from the creeks and rivers that make up the Guadalupe watershed, including water from storm drains, flows into the Guadalupe River, and then flows downstream into the San Francisco Bay at the Alviso Slough in Alviso. The Guadalupe watershed`s main tributaries include Los Gatos Creek, Trout Creek, Hendlys Creek, Ross Creek, Pheasant Creek, Rincon Creek, Herbert Creek, and Golf Creek. Six major reservoirs exist in the watershed: Calero Reservoir on Calero Creek, Guadalupe Reservoir on Guadalupe Creek, Almaden Reservoir on Los Alamitos Creek, Vasona Reservoir, Lexington Reservoir, and Lake Elsman on Los Gatos Creek.