San Lorenzo Creek ( es, Arroyo de San Lorenzo) is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data
The National Map
accessed March 15, 2011 year-round natural stream flowing through

Hayward, California Hayward () is a city located in Alameda County, California in the East Bay subregion of the San Francisco Bay Area. With a population of 162,954 as of 2020, Hayward is the sixth largest city in the Bay Area and the third largest in Alameda Coun ...

and other neighboring unincorporated communities into

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from a ...

at the

Hayward Regional Shoreline Hayward Regional Shoreline is a regional park located on the shores of the San Francisco Bay in Hayward, California. It is part of the East Bay Regional Parks system. The 1,713 acre park extends to the shores of San Lorenzo. Part of the park is fo ...

San Lorenzo Creek and bridge downtown Hayward

Watershed

The creek begins in

Castro Valley Castro Valley is a census-designated place (CDP) in Alameda County, California, United States. At the 2010 census, it was the fifth most populous unincorporated area in California and the twenty-third most populous in the United States. The popula ...

, and is the main tributary within the San Lorenzo Watershed, including the formerly independent Sulphur Creek, which had most of its flow diverted into San Lorenzo Creek in the 1960s to reduce the risk of flooding in

downtown Hayward Downtown Hayward is the original and current central business district of Hayward, California, United States, and is home to the current Hayward City Hall, along with the two previous city halls, Alex Giualini Plaza and the City Center Buildin ...

. Only in large flow events does some of the creek flow follow its old course into the Bay. The creek runs through the City of Hayward and the

unincorporated communities An unincorporated area is a region that is not governed by a local municipal corporation. Widespread unincorporated communities and areas are a distinguishing feature of the United States and Canada. Most other countries of the world either have ...

of Cherryland, Ashland and San Lorenzo and empties into San Francisco Bay. A portion of the

San Francisco Bay Trail The San Francisco Bay Trail is a bicycle and pedestrian trail that when finished will allow continuous travel around the shoreline of San Francisco Bay. As of 2020, of the trail have been completed. When finished, the trail will be over of p ...

runs along the mouth of the creek. The Cull Canyon and

Don Castro Don Castro (born December 28, 1949) is an American former professional motorcycle racer who is an inductee of the AMA Motorcycle Hall of Fame. During his career he was a works rider for Triumph and Yamaha' and a privateer on Triumph, Montesa, Y ...

reservoirs, both located within regional parks, feed into the creek.

History

The creek marks the farthest northward point of exploration by the

Portolá expedition thumbnail, 250px, Point of San Francisco Bay Discovery The Portolá expedition ( es, Expedición de Portolá) was a Spanish voyage of exploration in 1769–1770 that was the first recorded European land entry and exploration of the interior of ...

of 1769–70. Scouts camped at the creek before turning back to join the main party on the west side of the bay. Further explorations, led by Monterey presidio commander Pedro Fages in 1770 and 1772, also used the camp before continuing to the north. From records dating to 1772, the creek was previously known to Spanish colonists as Arroyo de San Salvador de Horta, and Arroyo de la Harina. The current name for the creek, Arroyo de San Lorenzo, dates to at least 1812, and was recorded as such in land grants from 1841 and 1842.

El Camino Viejo El Camino Viejo a Los Ángeles ( en, the Old Road to Los Angeles), also known as El Camino Viejo and the Old Los Angeles Trail, was the oldest north-south trail in the interior of Spanish colonial Las Californias (1769–1822) and Mexican Alta Cal ...

now Mission Boulevard, passed through what is now

San Lorenzo, California San Lorenzo (Spanish for "St. Lawrence") is a census-designated place (CDP) located in the East Bay of the San Francisco Bay Area in Alameda County, California, United States. The population was 29,581 at the 2020 census. It is an unincorporate ...

, crossing San Lorenzo Creek where Mission Boulevard crosses it now.

Ecology

San Lorenzo Creek historically supported

steelhead Steelhead, or occasionally steelhead trout, is the common name of the anadromous form of the coastal rainbow trout or redband trout (O. m. gairdneri). Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and ...

(the

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

form of the coastal rainbow trout ''Oncorhynchus mykiss irideus''), , and other

salmonids Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whit ...

. A 1997 paper states that, due to reasons tied to the ever increasing urbanization, dams, and their effect on the area, no sign of juvenile nor mature steelhead could be found in the creek. Since steelhead in the Bay Area and California's Central Coast were listed as threatened under the

Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...

in 1997, numerous organizations, and governmental agencies have cooperated on restoration projects to allow migratory fish from the Bay to reach spawning habitat in various Bay Area watersheds.

References

External links

San Lorenzo Creek Watershed Archive

Friends of San Lorenzo Creek

{{Authority control Rivers of Alameda County, California Geography of Hayward, California Tributaries of San Francisco Bay El Camino Viejo Rivers of Northern California

Watershed

History

Ecology

See also

References

External links