San Gregorio Creek
Encyclopedia
San Gregorio Creek is a river in San Mateo County
, California
. Its tributaries originate on the western ridges of the Santa Cruz Mountains
whence it courses southwest through steep forested canyons. The San Gregorio Creek mainstem begins at the confluence of Alpine and La Honda Creeks, whence it flows 12 miles (19.3 km) through rolling grasslands and pasturelands until it meets the Pacific Ocean
at San Gregorio State Beach
. It traverses the small unincorporated communities of La Honda
, San Gregorio
, Redwood Terrace and Sky Londa
.
's expedition from October 24–27, 1769, when he overshot his goal (Monterey Bay
) and went on to Pacifica
where he ascended Sweeney Ridge
and discovered San Francisco Bay
. The site is registered as California Historical Landmark
26. The creek was called Arroyo de San Gregorio in Spanish times and later, Arroyo Rodrigues in the 1850s.
of Alpine Creek
and La Honda Creek
in La Honda, and flows 11.8 miles (19 km) to its mouth at San Gregorio State Beach
in San Gregorio
.
The creek ends in a lagoon primarily in the incised channel upstream from the Highway 1
Bridge. The lagoon at its seasonal largest, is about five acres and six feet deep, and serves as habitat for Tidewater goby
(Eucyclogobius newberryi)) and rearing steelhead. Coho salmon do not rear in the lagoon but outgoing smolts use it to physiologically prepare for migration to saltwater.
This river floods occasionally on its path down CA Route 84
towards the Pacific Ocean
, most famously during the 1997 El Niño.
, Alpine
, Harrington
, El Corte de Madera
and Bogess Creek
s, contains approximately 33 miles (53.1 km) of historical Coho
(Oncorhynchus kisutch) rearing habitat. In the 1800s the creek had large enough salmon runs to support commercial harvest (Skinner, 1962). As part of the southern range of the Central California Coast Coho Evolutionarily Significant Unit (ESU), the creek is considered an attractive site for re-stocking. In fact, in 1998 the Draft Strategic Plan for Restoration of Endangered Coho Salmon South of San Francisco Bay identified San Gregorio Creek and its tributaries as one of nine creeks in which recovery of coho salmon (Oncorhynchus kisutch) is a priority. South of San Francisco to Monterey Bay the coho salmon was listed by the State of California as endangered in 1995. The San Gregorio watershed has seen recently increasing residential development but remains primarily pastoral with cattle and sheep grazing, timber harvesting, and recreational trails being the main commercial uses. Because of the large private ownership and development potential, water diversions and low base flows are an important issue in this watershed. In 1993, water rights in the San Gregorio watershed were adjudicated and a minimum stream bypass flow was established. However, the prescribed bypass flows are too low to assure viable coho salmon populations.
San Gregorio Creek is also part of the Central California Coast Steelhead trout (Oncorhynchus mykiss) ESU and historically supported a run of 1,000 fish as recently as 1971.
In 2007, the San Gregorio Creek watershed was targeted by the California Department of Fish and Game
for salmon recovery.
In a 2008 survey, both Coho salmon and steelhead trout were noted in the creek but threatened by Highway 84 related barriers to fish passage, as well as pressure from sedimentation from residential development, grazing and logging. The primary threat to salmonids in this report were bridge culverts at three sites which impede fish passage during low creek flows, and one site where a culvert from a small tributary is completely impassable in any season.
Four special-status animal species - California red-legged frog
(Rana draytonii), coho salmon, steelhead trout, and tidewater goby are the focus of a June, 2010 Watershed Management Plan.
Western Leatherwood (Dirca occidentalis), Santa Cruz Manzanita
(Arctostaphylos andersonii), and King’s Mountain Manzanita (Arctostaphylos regismontana), which are all included in the California Native Plant Society
's inventory of rare and endangered plants, have been documented in the La Honda Creek Open Space Preserve.
San Mateo County, California
San Mateo County is a county located in the San Francisco Bay Area of the U.S. state of California. It covers most of the San Francisco Peninsula just south of San Francisco, and north of Santa Clara County. San Francisco International Airport is located at the northern end of the county, and...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. Its tributaries originate on the western ridges of the Santa Cruz Mountains
Santa Cruz Mountains
The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central California, United States. They form a ridge along the San Francisco Peninsula, south of San Francisco, separating the Pacific Ocean from San Francisco Bay and the Santa Clara Valley, and continuing south,...
whence it courses southwest through steep forested canyons. The San Gregorio Creek mainstem begins at the confluence of Alpine and La Honda Creeks, whence it flows 12 miles (19.3 km) through rolling grasslands and pasturelands until it meets the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
at San Gregorio State Beach
San Gregorio State Beach
San Gregorio State Beach is a beach near San Gregorio, California, USA, south of Half Moon Bay. Part of the California State Park System, the beach lies just west of the intersection of State Route 1 and State Route 84...
. It traverses the small unincorporated communities of La Honda
La Honda, California
La Honda is a census-designated place in southern San Mateo County, California, United States. The population was 928 at the 2010 census. It is located in the Santa Cruz Mountains between Silicon Valley and the Pacific coast of California...
, San Gregorio
San Gregorio, California
-History:Named after Pope Gregory I , San Gregorio was a booming town in the 1850s, when wealthy San Franciscans would travel to the San Gregorio House by stagecoach to enjoy fishing, hunting, sea bathing, and boat races. The building still stands, but is no longer a functioning hotel. However, the...
, Redwood Terrace and Sky Londa
Sky Londa, California
Sky Londa is an unincorporated mountain community in San Mateo County, California located at the intersection of State Route 84 and State Route 35...
.
History
San Gregorio Creek is historically significant as the campsite for Spanish explorer Gaspar de PortolàGaspar de Portolà
Gaspar de Portolà i Rovira was a soldier, governor of Baja and Alta California , explorer and founder of San Diego and Monterey. He was born in Os de Balaguer, province of Lleida, in Catalonia, Spain, of Catalan nobility. Don Gaspar served as a soldier in the Spanish army in Italy and Portugal...
's expedition from October 24–27, 1769, when he overshot his goal (Monterey Bay
Monterey Bay
Monterey Bay is a bay of the Pacific Ocean, along the central coast of California. The bay is south of San Francisco and San Jose, between the cities of Santa Cruz and Monterey....
) and went on to Pacifica
Pacifica, California
Pacifica is a city in San Mateo County, California, on the coast of the Pacific Ocean between San Francisco and Half Moon Bay.-Overview:The City of Pacifica is spread along a six mile stretch of the north central California coastal beach and hills, nestled in several small valleys spanning between...
where he ascended Sweeney Ridge
Sweeney Ridge
Sweeney Ridge, a national park in Pacifica, California, is part of the Golden Gate National Recreation Area. Historically, the ridge was the location of the San Francisco Bay Discovery Site, as part of the Portolá Expedition on November 4, 1769.-Description:...
and discovered San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
. The site is registered as California Historical Landmark
California Historical Landmark
California Historical Landmarks are buildings, structures, sites, or places in the state of California that have been determined to have statewide historical significance by meeting at least one of the criteria listed below:...
26. The creek was called Arroyo de San Gregorio in Spanish times and later, Arroyo Rodrigues in the 1850s.
Watershed
The San Gregorio watershed is located approximately 11 miles (17.7 km) south of Half Moon Bay and covers approximately 61 square miles (158 km²). It is the second largest drainage in coastal San Mateo County, with approximately 45 miles (72.4 km) of "blue line" (perennial) streams. The mainstem of San Gregorio Creek begins at the confluenceConfluence
Confluence, in geography, describes the meeting of two or more bodies of water.Confluence may also refer to:* Confluence , a property of term rewriting systems...
of Alpine Creek
Alpine Creek
Alpine Creek is a small river in San Mateo County, California.It flows about , from its source near West Alpine Road about a mile southwest of Skyline Boulevard , to its confluence with La Honda Creek to form San Gregorio Creek in La Honda at California State Route 84.Alpine Creek passes through...
and La Honda Creek
La Honda Creek
La Honda Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek.It flows about , from its source near Bear Gulch Road and Skyline Boulevard , to its confluence with Alpine Creek to form San Gregorio Creek in La Honda.California State Route 84 follows the...
in La Honda, and flows 11.8 miles (19 km) to its mouth at San Gregorio State Beach
San Gregorio State Beach
San Gregorio State Beach is a beach near San Gregorio, California, USA, south of Half Moon Bay. Part of the California State Park System, the beach lies just west of the intersection of State Route 1 and State Route 84...
in San Gregorio
San Gregorio, California
-History:Named after Pope Gregory I , San Gregorio was a booming town in the 1850s, when wealthy San Franciscans would travel to the San Gregorio House by stagecoach to enjoy fishing, hunting, sea bathing, and boat races. The building still stands, but is no longer a functioning hotel. However, the...
.
The creek ends in a lagoon primarily in the incised channel upstream from the Highway 1
California State Route 1
State Route 1 , more often called Highway 1, is a state highway that runs along much of the Pacific coast of the U.S. state of California. It is famous for running along some of the most beautiful coastlines in the world, leading to its designation as an All-American Road.Highway 1 does not run...
Bridge. The lagoon at its seasonal largest, is about five acres and six feet deep, and serves as habitat for Tidewater goby
Tidewater goby
The tidewater goby Eucyclogobius newberryi is a goby native to lagoons of streams along the coast of California.-Taxonomy:The genus name translates as "true cycloid goby", referring to the scales, while the species epithet is in honor of J. S. Newberry. The tidewater goby is the sole member of its...
(Eucyclogobius newberryi)) and rearing steelhead. Coho salmon do not rear in the lagoon but outgoing smolts use it to physiologically prepare for migration to saltwater.
This river floods occasionally on its path down CA Route 84
California State Route 84
State Route 84 is a split-section California State Highway consisting of two sections. The first section is an east–west arterial road running from San Gregorio to Menlo Park, across the Dumbarton Bridge through Fremont and Newark and ending at I-580 in Livermore. The route overlaps the...
towards the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, most famously during the 1997 El Niño.
Ecology
The mainstem of San Gregorio Creek, in combination with its tributaries of La HondaLa Honda Creek
La Honda Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek.It flows about , from its source near Bear Gulch Road and Skyline Boulevard , to its confluence with Alpine Creek to form San Gregorio Creek in La Honda.California State Route 84 follows the...
, Alpine
Alpine Creek
Alpine Creek is a small river in San Mateo County, California.It flows about , from its source near West Alpine Road about a mile southwest of Skyline Boulevard , to its confluence with La Honda Creek to form San Gregorio Creek in La Honda at California State Route 84.Alpine Creek passes through...
, Harrington
Harrington Creek
Harrington Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek....
, El Corte de Madera
El Corte de Madera Creek
El Corte de Madera Creek is a small river in the Santa Cruz Mountains, San Mateo County, northern California...
and Bogess Creek
Bogess Creek
Bogess Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek....
s, contains approximately 33 miles (53.1 km) of historical Coho
Coho salmon
The Coho salmon, Oncorhynchus kisutch, is a species of anadromous fish in the salmon family. Coho salmon are also known as silver salmon or "silvers". It is the state animal of Chiba, Japan.-Description:...
(Oncorhynchus kisutch) rearing habitat. In the 1800s the creek had large enough salmon runs to support commercial harvest (Skinner, 1962). As part of the southern range of the Central California Coast Coho Evolutionarily Significant Unit (ESU), the creek is considered an attractive site for re-stocking. In fact, in 1998 the Draft Strategic Plan for Restoration of Endangered Coho Salmon South of San Francisco Bay identified San Gregorio Creek and its tributaries as one of nine creeks in which recovery of coho salmon (Oncorhynchus kisutch) is a priority. South of San Francisco to Monterey Bay the coho salmon was listed by the State of California as endangered in 1995. The San Gregorio watershed has seen recently increasing residential development but remains primarily pastoral with cattle and sheep grazing, timber harvesting, and recreational trails being the main commercial uses. Because of the large private ownership and development potential, water diversions and low base flows are an important issue in this watershed. In 1993, water rights in the San Gregorio watershed were adjudicated and a minimum stream bypass flow was established. However, the prescribed bypass flows are too low to assure viable coho salmon populations.
San Gregorio Creek is also part of the Central California Coast Steelhead trout (Oncorhynchus mykiss) ESU and historically supported a run of 1,000 fish as recently as 1971.
In 2007, the San Gregorio Creek watershed was targeted by the California Department of Fish and Game
California Department of Fish and Game
The California Department of Fish and Game is a department within the government of California, falling under its parent California Natural Resources Agency. The Department of Fish and Game manages and protects the state's diverse fish, wildlife, plant resources, and native habitats...
for salmon recovery.
In a 2008 survey, both Coho salmon and steelhead trout were noted in the creek but threatened by Highway 84 related barriers to fish passage, as well as pressure from sedimentation from residential development, grazing and logging. The primary threat to salmonids in this report were bridge culverts at three sites which impede fish passage during low creek flows, and one site where a culvert from a small tributary is completely impassable in any season.
Four special-status animal species - California red-legged frog
California Red-legged Frog
The California red-legged frog, Rana draytonii, is a moderate to large species of frog. It is known under the scientific name Rana draytonii, after being long included with the northern red-legged frog The California red-legged frog, Rana draytonii, is a moderate to large (4.4–14 cm) species...
(Rana draytonii), coho salmon, steelhead trout, and tidewater goby are the focus of a June, 2010 Watershed Management Plan.
Western Leatherwood (Dirca occidentalis), Santa Cruz Manzanita
Manzanita
Manzanita is a common name for many species of the genus Arctostaphylos. They are evergreen shrubs or small trees present in the chaparral biome of western North America, where they occur from southern British Columbia, Washington to California, Arizona and New Mexico in the United States, and...
(Arctostaphylos andersonii), and King’s Mountain Manzanita (Arctostaphylos regismontana), which are all included in the California Native Plant Society
California Native Plant Society
The California Native Plant Society is a California not-for-profit organization that seeks to increase understanding of California's native flora and to preserve that flora. Its "paramount purpose is to preserve wild plants".-History:...
's inventory of rare and endangered plants, have been documented in the La Honda Creek Open Space Preserve.
Tributaries
From mouth to head:- Palmer GulchPalmer GulchPalmer Gulch is a creeklet in San Mateo County, California and is a tributary of San Gregorio Creek....
- Coyote CreekCoyote Creek (San Mateo County)Coyote Creek is a stream in San Mateo County, California and is a tributary of San Gregorio Creek....
- Clear CreekClear Creek (San Mateo County)Clear Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek....
- El Corte de Madera CreekEl Corte de Madera CreekEl Corte de Madera Creek is a small river in the Santa Cruz Mountains, San Mateo County, northern California...
- Pine Tree GulchPine Tree GulchPine Tree Gulch is a valley in San Mateo County, California. It contains a small stream which is a tributary of San Gregorio Creek.The stream flows about from its source to its confluence with El Corte de Madera Creek.-Notes:...
- Pine Tree Gulch
- Bogess CreekBogess CreekBogess Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek....
- Kingston CreekKingston CreekKingston Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek. The average flow rate of this river is 60 gpm, as measured midway through the path of the river. The river is pumped for Irragation. Some crayfish live in the river....
(left bank) - Harrington CreekHarrington CreekHarrington Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek....
- La Honda CreekLa Honda CreekLa Honda Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek.It flows about , from its source near Bear Gulch Road and Skyline Boulevard , to its confluence with Alpine Creek to form San Gregorio Creek in La Honda.California State Route 84 follows the...
- Woodhams CreekWoodhams CreekWoodhams Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek.It flows about from its source on Langley Hill to its confluence with La Honda Creek, in the town of La Honda.-Notes:...
- Langley CreekLangley CreekLangley Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek.It flows about from its source on Langley Hill to its confluence with La Honda Creek, a short distance upstream from the town of La Honda.-Notes:...
- Woodruff CreekWoodruff CreekWoodruff Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek....
- Weeks CreekWeeks CreekWeeks Creek is a small creek tributary to La Honda Creek, which in turn is tributary to San Gregorio Creek in western San Mateo County, California. San Gregorio Creek drains to the Pacific Ocean at San Gregorio State Beach. The San Gregorio Creek watershed supports several species listed under the...
- Spanish Ranch CreekSpanish Ranch CreekSpanish Ranch Creek is a small river in San Mateo County, California.It flows about west from its source to its confluence with Weeks Creek, which in turn joins La Honda Creek in the La Honda Creek Regional Open Space, about 2 miles north of the town of La Honda.-Notes:...
- Spanish Ranch Creek
- Woodhams Creek
- Alpine CreekAlpine CreekAlpine Creek is a small river in San Mateo County, California.It flows about , from its source near West Alpine Road about a mile southwest of Skyline Boulevard , to its confluence with La Honda Creek to form San Gregorio Creek in La Honda at California State Route 84.Alpine Creek passes through...
- Mindego CreekMindego CreekMindego Creek is a small river in San Mateo County, California and is a tributary of San Gregorio Creek....
- Rodgers GulchRodgers GulchRodgers Gulch is a valley in San Mateo County, California. It contains a small stream which is a tributary of San Gregorio Creek.The stream flows about from its source on Mindego Hill to its confluence with Alpine Creek, just east of the boundary of the Heritage Grove Redwood Preserve.-Notes:...
- Mindego Creek