Our local streams and creeks were once an expansive and meandering network of waterways teaming with an abundance of wildlife. As Santa Clara Valley settled, we began to see the water’s natural paths blocked and straightened to better leverage water for the explosion of farming occurring throughout the Valley. As the population increased, a need to tame winter flooding led to the construction of large dams, which further restricted the wildlife’s movement along these artificial channels.
The Santa Clara Valley watershed includes the water from rain and irrigation, which all flows over our land surfaces carrying oil, grease, trash, and other pollutants into storm drains, creeks, and rivers that eventually flow directly to the San Francisco Bay.
According to the United States Geological Survey (USGS), Santa Clara County has a total of six different watersheds - with the Coyote and Guadalupe Watersheds as the two largest of the group.
The Coyote Watershed is the county's largest watershed and it extends from the urbanized valley floor upward to the vast natural areas of the Mount Hamilton range. The Coyote Creek is its main and longest waterway.
Guadalupe Watershed spans 170 square miles and includes the cities of San Jose, Los Gatos, Monte Sereno, Campbell, and Santa Clara. The Guadalupe Watershed includes: Guadalupe Creek and River, Los Gatos Creek, Ross Creek, Alamitos Creek, and Canoas Creek. The watershed also includes a number of reservoirs, including: Lexington, Vasona, Guadalupe, Almaden, Calero, and Lake Elsman.
FIf you're intersted in learning more about Santa Clara County Watershed and its history, then we recommend a great presentation by Janet M. Sowers, Justine T .Pearce and William Lettice & Associates, Inc. (supported by the Santa Clara Valley Water District and the Oakland Museum.)
The Santa Clara Valley Water District also provides an online interactive map of our creeks and rivers along with some “fast facts” about each waterway.
In our urbanized environment, the quality of our watershed’s waters is largely determined by the quality of the runoff water from our streets. In 1996, the Santa Clara Basin Watershed Management Initiative (SCBWMI) was established by the Environmental Protection Agency, State Water Resources Control Board, and the San Francisco Regional Water Quality Control Board to manage water resources within Santa Clara Basin Watersheds. You can learn more about this part of our watershed management here.