San Lorenzo Creek
San Lorenzo Creek is Alameda County's third largest tributary to San Francisco Bay. The watershed drains a 48-square-mile area, including all of Castro Valley and Cherryland, as well as small portions of Hayward, San Leandro and San Lorenzo. It discharges at the Hayward Regional Shoreline at a point halfway between Oakland International Airport and the San Mateo-Hayward Bridge (Hwy 92).
From Foothill Boulevard (in downtown Hayward) to its outfall at the Bay, a distance of about 4 stream miles, San Lorenzo Creek exists as an engineered flood control channel constructed by the Army Corps of Engineers (USACE) in the early 1960s.
Additional informative resources:
The Rainfall to Runoff Relationship
The magnitude of rainfall runoff can be predicted by estimating rainfall intensity and the antecedent soil saturation condition across the tributary area. This can be done using weather forecasting models, weather radar, rain gauge stations, and soil moisture meters. Stream gauges are used to measure and document actual runoff and may be used to warn of potential downstream flooding. Recorded data are subsequently analyzed to validate or adjust the theoretical rainfall/runoff relationship with the goal of increasing the accuracy of flood forecasting. Gauges used for this purpose in and around the San Lorenzo Creek Watershed are shown below.
Rainfall
Existing Rain Gauge Stations
ALERT Station 1930
ALERT Station 1932
ALERT Station 1934
ALERT Station 1950
ALERT Station 2104
ALERT Station 2118
164th Ave AC Fire Station #24
San Miguel Fire Station
Upper Crow
Lake Chabot Dam
Cull Maintenance Yard
Lower Palomares
Proposed Rain Gauge Stations
Upper Palomares
Niles
San Leandro Reservoir
Ward Creek Dam
Appian Way
Dublin Canyon Rd
Soil Saturation
Proposed Soil Moisture Meters
1 Eden Reservoir, Palomares Hills, Castro Valley
2 Upper Palomares
3 Mission Peak Park, Fremont
4 to be determined
Runoff
Existing Streamflow Gauge Stations
Cull Creek above Cull Reservoir - USGS
San Lorenzo Creek above Don Castro - USGS
San Lorenzo Creek at Hayward - USGS
Crow Creek near Hayward - USGS
Castro Valley Creek at Hayward - USGS
San Lorenzo Creek below Washington - USGS
Pedestrian Bridge at Vining & Hebron, San Lorenzo (Via Hermana) - ACFC
A St - ACFC
Center St - ACFC
Proposed Streamflow Gauge Stations
Washington Ave
Ward Creek Dam
Palomares Road
Crow Canyon Road
Foothill Boulevard
Crow Creek at Norris Creek
San Lorenzo Creek at Palomares Creek
Don Castro Park to Crow Creek Confluence
a recreational reservoir to an incised, natural channel
Recurring illicit encampment in the vicinity of Grove Way; evacuation of stream banks advised prior to anticipated high flows.
View of Don Castro Reservoir from crest of spillway.
Looking toward Don Castro Reservoir at the spillway bridge.
Don Castro Reservoir spillway.
Looking down the Don Castro Reservoir spillway.
Crow Creek Confluence to Center Street Bridge
an incised, natural channel
Center Street Bridge to A Street Bridge
an incised, natural channel
Streamflow Gage Station Locations: USGS 11181000 & District at Center and District at A Street.
Looking upstream from the reconstructed bank at A Street. The bank washed out during the December 31, 2022 storm.
Looking upstream toward the reconstructed bank at A Street.
Looking downstream from the reconstructed bank at A Street.
Looking upstream from the A Street bridge--location of District streamflow gage.
A Street Bridge to 2nd Street Bridge
an incised, natural channel
2nd Street Bridge to Foothill Boulevard / City Center Bridge
an incised, natural channel
Streamflow Gage Station Location: District
Looking upstream toward 2nd Street Bridge.
Looking downstream toward Foothill Boulevard bridge.
Foothill Boulevard / City Center Bridge to Hazel Street Bridge
a concrete-lined, rectangular channel
Hazel Street Bridge to Grove Way Bridge
a concrete-lined, rectangular channel
Grove Way Bridge to Mission Boulevard Bridge
a concrete-lined, rectangular channel
Mission Boulevard Bridge to UPRR Bridge at Western Boulevard
a concrete-lined, rectangular channel
UPRR Bridge at Western Boulevard to Meek Park Pedestrian Bridge
a concrete-lined, rectangular channel
Meek Park Pedestrian Bridge to UPRR Bridge near East Lewelling Boulevard
a concrete-lined, rectangular channel
UPRR Bridge near East Lewelling Boulevard to Meekland Avenue Bridge
a concrete-lined, rectangular channel
Meekland Avenue Bridge to Via Granada Bridge
a concrete-lined, rectangular channel
Looking downstream toward Via Granada bridge.
Via Granada Bridge to I-880 & Hesperian Bridges
a concrete-lined, rectangular channel
Looking downstream toward Hesperian bridge.
Hesperian Bridge to Washington Avenue Bridge
a concrete-lined, rectangular channel
Looking downstream at Washington Avenue bridge.
Washington Avenue Bridge to the vicinity of Budge St / Via Madeline
a concrete-lined, rectangular channel
Streamflow Gage Station Location: USGS 1181040 & District
Looking downstream from Washington Avenue bridge toward gage stations.
Vicinity of Budge St / Via Madeline to KIPP King Collegiate High School
a trapezoidal channel with concrete-lined side slopes
Streamflow Gage Station Location: District
KIPP King Collegiate High School to San Francisco Bay
a tidally influenced, engineered, trapezoidal, earthen channel
Roberts Landing Pump Station
Outlet to San Francisco Bay
The information above was compiled while assisting the Alameda County Flood Control and Water Conservation District with the development of a flood emergency response plan.
Partial funding for the project has been provided through an agreement with the California Department of Water Resources under the Safe Drinking Water, Water Quality & Supply, Flood Control, River & Coastal Bond Act of 2006.
