Creeks in the Watershed

Upper Watershed

Bolinas Creek: The most remote and pristine creek, a mostly native riparian corridor.

Crow Creek: The cool water temperatures support fish, although there is substantial grazing and illegal dumping and exotic species.

Cull Creek: The upper area of Cull Creek is primarily grazing land with good water quality and excellent wildlife habitat. The lower area suffers from non-native species invasion and illegal dumping. Cull Creek Dam, built in the early 1960s, provides some flood protection and is about .25 miles above where Crow Creek merges with Cull Creek.

Eden Creek: this meandering creek provides clean, cool water and good riparian habitat, although its hillsides are severely eroding and cattle often find their way into the creek.

Hollis Creek: While the creek flows through grassland and oak woodland, providing habitat for the red-legged frog, its hills are highly erosive and are a major source of silt in Don Castro Dam.

Norris Creek: Just north of Eden Creek, it features mostly native riparian habitat, although there is also erosion and sedimentation as well as bank failures.

Palomares Creek: Many diverse species of animals and fish rely on the habitat provided by this mostly native riparian corridor surrounded by rural development and equine facilities.

Upper San Lorenzo Creek: The healthiest section of the creek that gives the watershed its name, it flows directly into Don Castro Dam. The surrounding land is mostly suburban.

The natural riparian area meets the flood control channel at Foothill Blvd.

 

Middle Watershed

 

Castro Valley Creek: Flowing from urbanized Castro Valley into San Lorenzo Creek, it is subject to illicit discharges, non-native species, extensive channelization and undergrounding, pollution and illegal dumping. A section near the library has been daylighted and restored with native vegetation.

Chabot Creek: This urbanized creek is natural where it flows along Carlos Bee Park, and receives intense urban runoff which has resulted in a lack of wildlife.

Middle San Lorenzo Creek: Here the creek is a natural channel in a highly urbanized area; it provides a good riparian corridor with some deep pools and continuous water flow that could support fish. It changes to a culvert at Foothill Boulevard.

Upper Sulphur Creek: Flow from this creek has been diverted into San Lorenzo Creek in downtown Hayward through many underground drainage pipelines, and it acts as urbanized drainage.

Flood Channel

 

Lower Watershed

 

Lower San Lorenzo Creek: Below Foothill Boulevard, the creek is a concrete-lined channel with no habitat and high water temperatures, flowing out to the Bay through earthen levees. It’s subject to illegal dumping, polluted urban runoff and graffiti. Based on new data, the flood channel capacity is not sufficient and earthen levees are too low for FEMA to certify.

Bockman Canal: Now actually a series of storm drains that drain the western watershed south of San Lorenzo Creek, it has only one mile of open channel.

Estudillo Canal: An engineered flood control channel, it drains the western watershed north of San Lorenzo Creek. It was designed to provide flood protection for water flows that might occur during a storm that has less than a 10% chance of occurring during any given year. Current engineering standards call for protecting against storms that have a 1% chance of occurring in any given year. Upgrades to the canal are underway (more information is available at www.acgov.org/pwa.