The Stevens Creek watershed covers and area of approximately 29 square miles. The headwaters originate in the Santa Cruz Mountains within the City of Palo Alto and Santa Clara County. Much of the headwater area is protected open space managed by the County and the Mid Peninsula Open Space District. In the upper watershed the mainstem flows southeast through for about five miles along the San Andreas Fault, and another three miles northeast to the Stevens Creek Reservoir. From the Reservoir, the Creek flows northward for a total of 12.5 miles through the foothills in the Cities of Cupertino, and Los Altos, and across the alluvial plain through the cities of Sunnyvale, and Mountain View, finally draining into the Lower South San Francisco Bay. Below the reservoir, the watershed is largely developed as residential neighborhoods with commercial areas clustered along major surface streets such as El Camino Real.
Tributaries above the Reservoir include Montebello and Swiss Creeks. One tributary, Heney Creek, joins the mainstem 3.7 miles below the Reservoir.
Stevens Creek supports both warm and cold water native fish. Five native fish species that have been found in the creek include California roach, Sacramento sucker, threespine stickleback, rainbow/steelhead trout and Pacific lamprey.
- Watershed area: 29.2 square miles
- Number of tributary creeks: 12
- Miles of natural creek bed: 54.2
- Miles of Engineered Channel: 1.1
- Local jurisdictions: Santa Clara County, Palo Alto, Cupertino, Los Altos, Sunnyvale, Mountain View
- Percent area by land use:
- Residential 24.5%
- Industrial/Commercial 9.0%
- Forest 49.2%
- Rangeland 12.5%
- Other 4.8%
- Percent Impervious Area: 28.6%
- Miles of Underground Culvert or Stormdrain: 30.0
- Beneficial Uses: Cold Freshwater Habitat (COLD), Warm Freshwater Habitat (WARM), Wildlife Habitat (WILD), Fish Migration (MIGR), Water Contact Recreation (REC-1), Noncontact Water Recreation (REC-2), Freshwater Replenishment (FRSH), Groundwater Recharge (GWR), Municipal Supply (MUN)
- Water Quality Impairments:
- Stevens Creek: Urban Pesticide Toxicity (Diazinon), Water Temperature, Toxicity, Trash
- Stevens Creek Reservoir: Legacy pesticides (Chlordane and Dieldrin), Mercury, PCBs