Guadalupe Watershed

The Guadalupe River Watershed drains approximately 171 square miles.  The headwaters drain from the eastern Santa Cruz Mountains near the summit of Loma Prieta in heavily forested unincorporated county land with pockets of low-density residential developments.  The Guadalupe River actually begins on the Valley floor at the confluence of Alamitos Creek and Guadalupe Creek, just downstream of Coleman Road in San Jose.  From here it flows north, approximately 14 miles until it discharges to the Lower South San Francisco Bay via Alviso Slough.  On its journey, it traverses through the town of Los Gatos, and the Cities of San Jose, Campbell, and Santa Clara, and is joined by three other tributaries:  Ross, Canoas, and Los Gatos Creek.  The largest of these, Los Gatos Creek joins the mainstem about 3 ½ miles downstream of its origination, and passes from unincorporated county land, through the towns of Monte Sereno, Los Gatos, and the Cities of Campbell and San Jose.

The upper watershed is characterized by heavily forested areas with pockets of low-density development.  As the creeks traverse the alluvial foothills, residential density gradually increases to high density on the valley floor.  Commercial development is focused along major surface streets.  Industrial developments are located closer to the Bay, primarily downstream of the El Camino Real crossing.

Six major reservoirs exist in the watershed:  Calero Reservoir on Calero Creek, Guadalupe Reservoir on Gaudalupe Creek, Almaden Reservoir on Alamitos Creek, Vasona Reservoir, Lexington Reservoir, and Lake Elsman on Los Gatos Creek. 

Watershed Facts

  • Drainage area:  171.3 square miles
  • Number of creeks: 50 (wmi) (45 querying creeks.shp in gis)
  • Miles of creek:  207.3
  • Miles of Engineered Channel:  45.5
  • Miles of Underground Culvert or Stormdrain:  265.3
  • Local jurisdictions:  Santa Clara County, Los Gatos, San Jose, Santa Clara
  • Percent area by land use:
    • Residential 29.6%
    • Industrial/Commercial 13.6%
    • Forest 34.7%
    • Rangeland 15.5%
    • Other 6.6%
  • Percent Impervious Area:  37.1%
  • Beneficial Uses:  COLD, WARM, WILD, SPWN, REC-1, REC-2, FRSH, GWR, MUN 

back to watersheds map