San Mateo Creek (''Spanish for'': St. Matthew Creek) is a perennial stream whose watershed includes

Crystal Springs Reservoir Crystal Springs Reservoir is a pair of artificial lakes located in the northern Santa Cruz Mountains of San Mateo County, California situated in the rift valley created by the San Andreas Fault just to the west of the cities of San Mateo and H ...

, for which it is the only natural outlet after passing

Crystal Springs Dam Crystal Springs Dam is a gravity dam constructed across the San Mateo Creek which is in San Mateo County, California. It impounds water to form the Lower Crystal Springs Reservoir which sits atop the San Andreas Fault in a rift valley created ...

History

After discovering San Francisco Bay from

Sweeney Ridge Sweeney Ridge, is a hilly hiking area of ridges and ravines between San Bruno, California, San Bruno and Pacifica, California, about a 25-minute drive south from San Francisco. The ridge's 1,200-foot-high summit, covered with coastal scrub and gra ...

on November 4, 1769, the Portolà expedition descended what Portolà called the ''Cañada de San Francisco'', now

San Andreas Creek San Andrés Creek (''Spanish for'': St. Andrew's Creek), now called San Andreas Creek, is a perennial stream that flows southeasterly along the San Andreas Fault from Sweeney Ridge in San Mateo County, California, providing the inflow to and outf ...

(or possibly San Mateo Creek). "Laguna Grande" is where the party camped (now covered by the Upper Crystal Springs Reservoir). The Laguna Grande place name is also shown on the 1840s diseño del

Rancho Cañada de Raymundo Rancho Cañada de Raymundo was a Mexican land grant in present-day San Mateo County, California given August 4, 1840 to Raimundo (also known as Raymundo), a native of Baja California, who was sent out by the padres of Mission Santa Clara to capture ...

and an 1856 plat. The campsite is marked by California Historical Marker No. 94 "Portola Expedition Camp". They camped here a second time on November 12, on their return trip. Padre Palóu, on an expedition from

Mission San Carlos Borromeo Mission San Carlos Borromeo del Río Carmelo, or Misión de San Carlos Borromeo de Carmelo, first built in 1797, is one of the most authentically restored Catholic mission churches in California. Located at the mouth of Carmel Valley, Californi ...

(Carmel) to explore the western side of San Francisco Bay led by Captain

Fernando Rivera Fernando is a Spanish and Portuguese given name and a surname common in Spain, Portugal, Italy, France, Switzerland, former Spanish or Portuguese colonies in Latin America, Africa, the Philippines, India, and Sri Lanka. It is equivalent to the G ...

, renamed Portola's ''Cañada de San Francisco'' to ''Cañada de San Andrés'' on November 30, 1774, it being the feast day of

St. Andrew Andrew the Apostle ( grc-koi, Ἀνδρέᾱς, Andréās ; la, Andrēās ; , syc, ܐܰܢܕ݁ܪܶܐܘܳܣ, ʾAnd’reʾwās), also called Saint Andrew, was an apostle of Jesus according to the New Testament. He is the brother of Simon Peter ...

. Palou's name was later applied to the

San Andreas fault The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonics, tectonic boundary between the Pacific Plate and the North American Plate, and its motion is Fault (geology)#Strike-slip fau ...

(misspelled) when the fault was discovered to be the creator of the valley. In 1776, the expedition led by Captain Juan Bautista de Anza, rather than stay on the coast as Portola had done, followed an inland route from

Monterey, California Monterey (; es, Monterrey; Ohlone: ) is a city located in Monterey County on the southern edge of Monterey Bay on the U.S. state of California's Central Coast. Founded on June 3, 1770, it functioned as the capital of Alta California under bo ...

established by

Pedro Fages Pedro Fages (1734–1794) was a Spanish soldier, explorer, first Lieutenant Governor of the Californias under Gaspar de Portolá. Fages claimed the governorship after Portolá's death, acting as governor in opposition to the official governor ...

in 1770. De Anza descended the

Santa Clara Valley The Santa Clara Valley is a geologic trough in Northern California that extends 90 miles (145 km) south–southeast from San Francisco to Hollister. The longitudinal valley is bordered on the west by the Santa Cruz Mountains and on the east ...

to San Francisco Bay and followed its western shoreline up the peninsula to San Francisco. The de Anza party selected the sites for

Mission San Francisco de Asís Mission San Francisco de Asís ( es, Misión San Francisco de Asís), commonly known as Mission Dolores (as it was founded near the Dolores creek), is a Spanish Californian mission and the oldest surviving structure in San Francisco. Located i ...

(''Mission Dolores'') and the

Presidio of San Francisco The Presidio of San Francisco (originally, El Presidio Real de San Francisco or The Royal Fortress of Saint Francis) is a park and former U.S. Army post on the northern tip of the San Francisco Peninsula in San Francisco, California, and is part o ...

. De Anza picked up Portola's trail at

San Francisquito Creek San Francisquito Creek (Spanish for "Little San Francisco" - the "little" referring to size of the settlement compared to Mission San Francisco de Asís) is a creek that flows into southwest San Francisco Bay in California, United States. Histo ...

, following the Cañada de San Andrés north from there. On the return to Monterey, the party camped on the banks of San Mateo Creek on March 29, 1776. In de Anza's diary on March 29, 1776, he wrote: "Night having fallen, at a quarter past six I went down to the arroyo of San Andreas and to another, that of San Matheo, where it descends to empty into the estuary. There I found in our camp nearly all the men of the village, very friendly, content, and joyful, putting themselves out to serve us in every way, a circumstance which I have noted in all the natives seen from the 26th up to now, but one which I had not experienced theretofore since leaving the people of the Colorado River." It is likely that de Anza had met the Ssalson tribe of Ohlone people. The records of the Mission San Francisco de Asís indicate that the Ssalson had three villages along San Mateo Creek and San Andreas Creek named Altagmu, Aleitac, and Uturbe. By 1794, the members of the tribe had moved to the mission. Shortly thereafter, the rest of the de Anza party – families, soldiers, and priests on their way to help establish the presidio and mission – also camped here for three days, June 24–27, 1776. A plaque labelled "California State Historical Landmark No. 47 Anza Expedition Camp" is located at Arroyo Court, one block west on West 3rd Avenue, San Mateo.

Watershed

San Mateo Creek's source elevation is at almost 1,000 feet on Sweeney Ridge from which it flows southeasterly (in a valley east of Cahill Ridge and west of Sawyer Ridge) for 11.2 km (7 mi) before entering the northwest arm of Lower Crystal Springs Reservoir. The northeast arm of Lower Crystal Springs Reservoir is formed by San Mateo Creek's tributary,

which descends to the Reservoir southeast along the

San Andreas Rift The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal). ...

. Another tributary, Laguna Creek, flows northwards from Woodside with its source on Edgewood County Park and Natural Preserve, and historically fed Laguna Grande and then joined San Mateo Creek just upstream from Crystal Springs Canyon, where San Mateo Creek turned east to flow through the canyon. Laguna Grande was submerged when an earthen dam (this was the first Crystal Springs Dam) was constructed in 1877, forming Upper Crystal Springs Reservoir. The old earthen dam became a causeway between Upper and Lower Crystal Springs Reservoirs when the latter was formed by Herman Schussler's concrete Crystal Springs Dam, which dammed up San Mateo Creek in 1888 to form the lower reservoir. The causeway is now crossed by Highway 92. In addition to San Mateo Creek and its San Andreas Creek and Laguna Creek tributaries, the waters of Crystal Springs Reservoir consist of runoff from the eastern slopes of the Montara block of the

Santa Cruz Mountains The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central and Northern California, United States. They form a ridge down the San Francisco Peninsula, south of San Francisco. They separate the Pacific Ocean from ...

and imported

Hetch Hetchy Aqueduct Hetch Hetchy is a valley, a reservoir, and a water system in California in the United States. The glacial Hetch Hetchy Valley lies in the northwestern part of Yosemite National Park and is drained by the Tuolumne River. For thousands of years bef ...

water deriving from the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

. The two Crystal Springs lakes and San Andreas Lake used to be known as ''Spring Valley Lakes'' for the Spring Valley Water Company which owned them. Lower Crystal Springs Reservoir now covers the town of ''Crystal Springs'' which grew up around a resort of the same name. From the

San Mateo Creek flows generally northeast 8 km (5 mi) through San Mateo where it is partly intermittent and altered, to San Francisco Bay about 1.1 km (0.7 mi) west of the mouth of Seal Slough. This

watercourse A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams are ...

lies entirely within

San Mateo County San Mateo County ( ), officially the County of San Mateo, is a county located in the U.S. state of California. As of the 2020 census, the population was 764,442. Redwood City is the county seat, and the third most populated city following Daly ...

and flows generally eastward to discharge 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 ...

Ecology

San Mateo Creek once hosted

coho salmon The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientific species name i ...

(''Oncorhynchus kisutch'') as evidenced by specimens collected by Professor Alexander Agassiz of

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

in the 1850s and 1860s. He also collected

steelhead trout 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 N ...

(''Oncorhynchus mykiss'') from the creek. Historical records indicate that

Chinook salmon The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus ''Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ve ...

(''Oncorhynchus tshawytscha'') occurred in at least two

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...

watersheds, San Mateo Creek in San Mateo County and

San Leandro Creek San Leandro Creek ( es, Arroyo de San Leandro) is a year-round natural stream in the hills above Oakland in Alameda County and Contra Costa County of the East Bay in northern California.U.S. Geological Survey. National Hydrography Dataset high-res ...

in Alameda County.

Fog drip Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Reprint from Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily in ...

may play a key role in the precipitation in the upper watershed. On Cahill Ridge, just west of San Mateo Creek and east of

Pilarcitos Creek Pilarcitos Creek (Spanish for: ''Little Pillars or Pillaries Creek'') is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed March 15, 2011 coastal stream in San Mateo County, California, ...

, at an altitude of 1,000 feet, Oberlander measured fog drip beneath

tanoak ''Notholithocarpus densiflorus'', commonly known as the tanoak or tanbark-oak, is a broadleaf tree in the family Fagaceae, and the type species of the genus ''Notholithocarpus''. It is native to the far western United States, particularly Oregon ...

(''Lithocarpus densiflorus''), coast redwood and three Douglas fir trees, the latter 125 feet tall. He found that the trees most exposed produced the most precipitation and in five weeks of measurement (July 20-August 28, 1951) fog drip below the tanoak produced 59 inches of precipitation, more than the total annual precipitation on nearby grasslands and chaparral. The Douglas fir produced 7-17 inches of fog drip and appeared to provide unique conditions supporting the orchids giant helleborine (''Epipactis gigantea'') and phantom orchid (''Cephalanthera austiniae''), since these plants were found exclusively in these moist ridge tops. The upper reach of the lower watershed of San Mateo Creek below

consists of open space and sparsely developed residential areas of the cities of Hillsborough and

San Mateo, California San Mateo ( ; ) is a city in San Mateo County, California, on the San Francisco Peninsula. About 20 miles (32 km) south of San Francisco, the city borders Burlingame to the north, Hillsborough to the west, San Francisco Bay and Foster C ...

. This upper reach consists of closed canopy

California oak woodland California oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico. Oak woodland is widespread at lower elevations in coasta ...

and serpentine

grassland A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...

. The creek roughly parallels Crystal Springs Road through this section. Due to the unusual

microclimate A microclimate (or micro-climate) is a local set of atmospheric conditions that differ from those in the surrounding areas, often with a slight difference but sometimes with a substantial one. The term may refer to areas as small as a few squ ...

and presence of abundant serpentine there are an unusual number of rare plants in the upper catchment basin. The middle reach consists of increasingly dense single family and multifamily residential land use along with some adjacent school, park and commercial uses. In the lower phase of the middle reach, San Mateo Creek is fully

culvert A culvert is a structure that channels water past an obstacle or to a subterranean waterway. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. In the United Kingdom ...

ed through downtown San Mateo. In the lowest reach San Mateo Creek becomes tidal and discharges to

between Ryder Park and Seal Point Park. The creek mouth area contains

slough Slough () is a town and unparished area in the unitary authority of the same name in Berkshire, England, bordering west London. It lies in the Thames Valley, west of central London and north-east of Reading, at the intersection of the M4 ...

and

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

habitats including

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal fl ...

s that are known

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

of the

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

California clapper rail Ridgway's rail (''Rallus obsoletus'') is a near-threatened species of bird. It is found principally in California's San Francisco Bay to southern Baja California. A member of the rail family, Rallidae, it is a chicken-sized bird that rarely fli ...

. San Mateo Creek was federally designated in 2002 as a section 303 impaired watershed for the substance

diazinon Diazinon (IUPAC name: ''O'',''O''-Diethyl ''O''- -methyl-6-(propan-2-yl)pyrimidin-2-ylphosphorothioate, INN - Dimpylate), a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company ( ...

; however, diazinon has been banned for golf course use by the U.S. Government. There is one golf course that provides

surface runoff Surface runoff (also known as overland flow) is the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when th ...

to San Mateo Creek in the city of San Mateo, and Crystal Springs Golf Course that drains to the Crystal Springs Reservoir.

Watercourse gallery

References

External links