The Alameda Watershed lands are split between Alameda (23,000 acres) and Santa Clara (13,000 acres) Counties and contain two reservoirs -- the San Antonio Reservoir to the north and the Calaveras Reservoir to the south.  Highway I-680 and Route 84 meet in the northern portion of the Watershed, and Calaveras Road extends north-south down the center.  Milpitas and Fremont lie to the west and Pleasanton and Livermore are located to the northeast.

The SFPUC Alameda Watershed lands include 30,000 acres of primary watershed, lands which are tributary to San Antonio and Calaveras Reservoirs as well as lands which drain into Alameda Creek above the proposed Fish Release and Recapture Facility. The primary watershed lands are the most sensitive lands in terms of water quality protection. SFPUC Alameda Watershed Lands also include 6,000 acres of secondary watershed. These are lands where runoff enters Alameda Creek below the proposed Fish Release and Recapture Facility and is not currently captured for water supply purposes. 

Land Use
In contrast to the Peninsula Watershed lands, a portion of the Alameda Watershed lands are leased by and produce revenue for the SFPUC from a variety of uses including grazing, plant nurseries and quarry operations. Several utility companies have easements for routing of public utilities such as gas pipelines, electrical transmission lines and water aqueducts. A portion of the SFPUC’s lands are also leased by the East Bay Regional Park District as part of the Sunol-Ohlone Regional Wilderness.  The portion operated by the District includes many pedestrian, equestrian, and bicycle trails.

Open public access to interior parts of the SFPUC-owned watershed lands is prohibited because of the risk of fire and potential degradation of water quality and natural resources.  The SFPUC, however, does allow access to some internal fire roads by permit for research or educational purposes to groups accompanied by volunteer leaders.

Geology
The southern portion of the Alameda Creek Watershed drains a 175-square mile area that includes Mount Hamilton and is approximately three times larger than the SFPUC-owned portion. This dry and rugged Watershed has a varied topography that ranges from flatlands to areas of over sixty percent slope.

The Calaveras fault runs through the central portion of this Watershed, and elevations rise to over 3,000 feet in some areas. Soils in the San Antonio Reservoir area are subject to high erosion because of the steep slopes and the proximity to faults.

An intricate system of streams and tributaries winds through the Alameda Watershed; the main streams on SFPUC land include San Antonio, Indian and Alameda Creeks in the north and Calaveras, Arroyo Hondo and Alameda Creeks in the south.  

Natural Environment
The Alameda Watershed provides habitat for a variety of wildlife.  Grassland communities cover more than 50 percent fo the watershed and woodlands cover about 22 percent.  Other habitats include freshwater marshes, where streams discharge into resrvoirs, and bursh, scrub, and chaparral communities in the flatter, drier, or steeper lands.

Ridgelands and open water make the area an attractive winter foraging and resting habitat for migrating and resident bird species, drawing birds of prey, waterfowl, and perching birds.  In total, the watershed contains more than 17 types of wildlife habitat that support a range of animals, including tule elk, black-tailed deer, coyote, mountain lions, and bald eagles.

Cattle have grazed on the Alameda Creek Watershed for more than a century.  The SFPUC has taken measures to reduce the potential impacts of erosion, native plant displacement, and water quality degradation often associated with grazing.  Strict grazing management pratices --  from fencing creeks to keep out livestock to limiting the number of animals allowed in the watershed  --  have helped maintain high water quality and reduce the threat of wildfire.  Grazing is considered an important tool in managing fire, because it reduces the amount of grass and other vegetation that might quickly ignite if left unmanaged during the area's hot, dry summers.