San Diego Creek is a
urban waterway flowing into
Upper Newport Bay
The Upper Newport Bay (known locally as "The Back Bay") is a large coastal wetland (an estuary) in Newport Beach, Southern California and a major stopover for birds on the Pacific Flyway. Dozens of species, including endangered ones, can be ob ...
in
Orange County
Orange County most commonly refers to:
*Orange County, California, part of the Los Angeles metropolitan area
Orange County may also refer to:
U.S. counties
*Orange County, Florida, containing Orlando
*Orange County, Indiana
*Orange County, New ...
,
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
.
Its
watershed
Watershed is a hydrological term, which has been adopted in other fields in a more or less figurative sense. It may refer to:
Hydrology
* Drainage divide, the line that separates neighbouring drainage basins
* Drainage basin, called a "watershe ...
covers in parts of eight cities, including
Irvine Irvine may refer to:
Places On Earth Antarctica
*Irvine Glacier
*Mount Irvine (Antarctica)
Australia
*Irvine Island
*Mount Irvine, New South Wales
Canada
*Irvine, Alberta
* Irvine Inlet, Nunavut
United Kingdom
*Irvine, North Ayrshire, Scotla ...
,
Tustin
Tustin is a city located in Orange County, California, in the Los Angeles metropolitan area. In 2020, Tustin had a population of 80,276. The city is located next to the county seat, Santa Ana, California, Santa Ana, and does not include the un ...
, and
Costa Mesa
Costa may refer to:
Biology
* Rib (Latin: ''costa''), in vertebrate anatomy
* Costa (botany), the central strand of a plant leaf or thallus
* Costa (coral), a stony rib, part of the skeleton of a coral
* Costa (entomology), the leading edge of t ...
.
From its headwaters in
Laguna Woods
Laguna Woods (''Laguna'', Spanish for "Lagoon") is a city in Orange County, California, United States. The population was 16,192 at the 2010 census, down from 16,507 at the 2000 census, with a median age of 78.
Laguna Woods became Orange Count ...
the creek flows northwest to its confluence with
Peters Canyon Wash
Peters Canyon Wash is a tributary of San Diego Creek in central Orange County in the U.S. state of California. About long north-south, the wash, now mostly channelized, flows in a relatively straight course southwest from the Peters Canyon Rese ...
, where it turns abruptly southwest towards the bay. Most of the creek has been converted to a concrete
flood control channel
Flood control channels are large and empty basins which let water flow in and out (except during flooding) or dry channels that run below the street levels of some larger cities, so that if and when a flood occurs, the water will run into these ch ...
, but it also provides important aquatic and
riparian
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...
habitat along its course and its tidal
estuary
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...
.
The watershed is heavily
urbanized
''Urbanized'' is a documentary film directed by Gary Hustwit and released on 26 October 2011. It is considered the third of a three-part series on design known as the Design Trilogy; the first being ''Helvetica'', about the typeface, and the seco ...
with master planned residential and commercial development. It accounts for 80 percent of the whole Newport Bay watershed, which has an urban population of over 700,000. There is also agriculture, high-tech industry and of designated open space.
Orange County Great Park
The Great Park is a public park located in Irvine, California, with a focus on sports, agriculture, and the arts. It is a non-aviation reuse of the decommissioned Marine Corps Air Station (MCAS) El Toro. The Orange County park comprises 28.8% ...
(formerly
El Toro Marine Corps Air Station
Marine Corps Air Station El Toro was a United States Marine Corps Air Station located next to the community of El Toro, near Irvine, California.
Before it was decommissioned in 1999, it was the home of Marine Corps Aviation on the West Coast. ...
), one of the largest urban parks in the US, is also situated in the watershed.
Course
San Diego Creek rises in the foothills of the
Santa Ana Mountains
The Santa Ana Mountains are a short peninsular mountain range along the coast of Southern California in the United States. They extend for approximately southeast of the Los Angeles Basin largely along the border between Orange and Riverside co ...
in the residential communities of
El Toro El Toro, Spanish for "the bull", may refer to:
Geography
* El Toro (Mallorca), a neighbourhood in the municipality of Calvià on the island of Mallorca
* El Toro, Castellón, a town in Castellón, Spain
* El Toro (Jujuy), a rural municipality and ...
, and
Lake Forest. Most of its upper course is culverted under subdivisions of El Toro and Irvine. It flows west, fed by tributaries from northern
Laguna Canyon
Laguna Canyon (also called Cañada de las Lagunas, meaning "Lake Canyon" in Spanish) is a canyon that cuts through the San Joaquin Hills in southern Orange County, California, in the United States, directly south of the city of Irvine. The canyo ...
and from the
Santa Ana Mountains
The Santa Ana Mountains are a short peninsular mountain range along the coast of Southern California in the United States. They extend for approximately southeast of the Los Angeles Basin largely along the border between Orange and Riverside co ...
to the north of the creek. After crossing under Interstate 405 near the site of the former
Irvine Meadows Amphitheatre
Irvine Meadows Amphitheatre (formerly known as Verizon Wireless Amphitheatre) was an amphitheater operating from 1981-2016 in Irvine, California. The venue was built in 1980 funded by four local private investors under the Irvine Meadows Partners ...
, the creek enters an artificial channel and receives
Serrano Creek Serrano Creek is a roughly tributary of San Diego Creek in the U.S. state of California. The creek starts in the Santa Ana Mountains in a canyon in Whiting Ranch Wilderness Park, near the boundary of the Cleveland National Forest. It then flows sou ...
via an underground culvert on the right bank. Directly after the confluence, it passes under
California State Route 133
State Route 133 (SR 133) is a state highway in the U.S. state of California, serving as an urban route in Orange County. It connects SR 1 in Laguna Beach through the San Joaquin Hills with several freeways in Irvine, ending at the SR ...
. It then flows northwest in a nearly straight course through
East Irvine
Old Town Irvine was designated a California Historic Landmark (No.1004) on November 11, 1991. Old Town Irvine is in the city of Irvine, California in Orange County A Historic marker is at 14980 Sand Canyon Avenue, Irvine. The marker is to ...
and the City of Irvine, receiving
Agua Chinon Creek
Agua Chinon Creek or Agua Chinon Wash is an urban stream in the city of Irvine, Orange County, California. The creek flows southwest from its headwaters in the foothills of the Santa Ana Mountains for about to join San Diego Creek near the Ver ...
,
Bee Canyon Wash, and the
Marshburn Channel from the right. All these tributaries originate in the Santa Ana Mountains and are channelized for most of their lengths through Irvine. A few miles past the confluence with Marshburn Channel, San Diego Creek receives its main tributary, Peters Canyon Creek, on the right bank. The creek begins at Peters Canyon Reservoir in the Santa Ana Mountains and runs about south-southwest. Although historically it was a smaller tributary, due to present-day flood control purposes, the channel of Peters Canyon is wider than the channel of San Diego Creek when they join.
[ ]
At the confluence with Peters Canyon Creek, San Diego Creek turns abruptly southwest, flowing underneath Interstate 405 for the second time. After flowing beneath the highway, San Diego Creek enters a series of slackwater pools, known as the San Joaquin Marsh, in the
San Joaquin Wildlife Sanctuary
The San Joaquin Marsh Wildlife Sanctuary is a constructed wetland in Irvine, California, in the flood plain of San Diego Creek just above its outlet into the Upper Newport Bay.
History
The site is owned by the Irvine Ranch Water District; it ...
. The partially man-made marsh stretches approximately to where San Diego Creek turns abruptly westward. The creek receives Bonita Creek on the left bank just a few hundred yards upstream frow where it empties into
Upper Newport Bay
The Upper Newport Bay (known locally as "The Back Bay") is a large coastal wetland (an estuary) in Newport Beach, Southern California and a major stopover for birds on the Pacific Flyway. Dozens of species, including endangered ones, can be ob ...
, which eventually discharges into the
Pacific Ocean
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
.
[
]
Watershed
The San Diego Creek drains a roughly rectangular shaped watershed of in central Orange County. Although most of the watershed is located in Irvine, it also includes parts of the incorporated cities of Aliso Viejo
Aliso Viejo (Spanish for "Old Sycamore") is a city in the San Joaquin Hills of southern Orange County, California. It had a population of 47,823 as of the 2010 census, up from 40,166 as of the 2000 census. It became Orange County's 34th city on ...
, Laguna Hills
Laguna Hills (; ''Laguna'', Spanish for "Lagoon") is a city in south Orange County, California, United States. Its name refers to its proximity to Laguna Canyon and the much older Laguna Beach. Other newer cities nearby—Laguna Niguel and Lagun ...
, Laguna Woods
Laguna Woods (''Laguna'', Spanish for "Lagoon") is a city in Orange County, California, United States. The population was 16,192 at the 2010 census, down from 16,507 at the 2000 census, with a median age of 78.
Laguna Woods became Orange Count ...
, Lake Forest, Orange
Orange most often refers to:
*Orange (fruit), the fruit of the tree species '' Citrus'' × ''sinensis''
** Orange blossom, its fragrant flower
*Orange (colour), from the color of an orange, occurs between red and yellow in the visible spectrum
* ...
, Santa Ana, and Tustin
Tustin is a city located in Orange County, California, in the Los Angeles metropolitan area. In 2020, Tustin had a population of 80,276. The city is located next to the county seat, Santa Ana, California, Santa Ana, and does not include the un ...
. The watershed forms a flat, highly urbanized basin which is bounded on the north by the Loma Ridge, the "front range" of the Santa Ana Mountains, which separates it from the valley of Santiago Creek
Santiago Creek is a major watercourse in Orange County in the U.S. state of California. About long, it drains most of the northern Santa Ana Mountains and is a tributary to the Santa Ana River. It is one of the longest watercourses entirely within ...
. Loma Ridge elevations range from . Santiago Creek flows west to join the Santa Ana River, which drains the coastal plain area immediately west of the San Diego Creek watershed. On the southeast, the San Diego Creek watershed borders that of Aliso Creek and Laguna Canyon
Laguna Canyon (also called Cañada de las Lagunas, meaning "Lake Canyon" in Spanish) is a canyon that cuts through the San Joaquin Hills in southern Orange County, California, in the United States, directly south of the city of Irvine. The canyo ...
Creek. To the south the watershed is bounded by the low San Joaquin Hills which generally rise to elevations of .
The San Diego Creek watershed is about 80 percent of the total land draining into Newport Bay – one of the largest estuaries in Southern California – and contributes between 77 and 95 percent of the total fresh water inflow to the bay. The population of the Newport Bay watershed in 2000 was about 705,000, which is projected to grow to 730,000 by 2030. The primary urban land use in the San Diego Creek watershed (not including the rest of Newport Bay) is transportation and communications. Roads (Interstate 5
Interstate 5 (I-5) is the main north–south Interstate Highway on the West Coast of the United States, running largely parallel to the Pacific coast of the contiguous U.S. from Mexico to Canada. It travels through the states of Califor ...
/405
__NOTOC__
Year 405 ( CDV) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Stilicho and Anthemius (or, less frequently, year 1158 ''Ab ...
, CA 55/ 73/133 133 may refer to:
*133 (number)
* AD 133
*133 BC
*133 (song)
*133 (New Jersey bus) 133 may refer to:
*133 (number)
* AD 133
*133 BC
*133 (song) 133 may refer to:
*133 (number)
*AD 133
*133 BC
*133 (song)
*133 (New Jersey bus) 133 may refer to:
* ...
/241
Year 241 ( CCXLI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Gordianus and Pompeianus by the Romans (or, less frequently, year ...
/261
__NOTOC__
Year 261 ( CCLXI) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Gallienus and Taurus (or, less frequently, year 1014 ''A ...
), rail and airports (John Wayne Airport
John Wayne Airport is a commercial and general aviation airport that serves Orange County, California, and the Greater Los Angeles area. The airport is located in an unincorporated area of Orange County, and it is owned and operated by the cou ...
, El Toro Marine Corps Air Station
Marine Corps Air Station El Toro was a United States Marine Corps Air Station located next to the community of El Toro, near Irvine, California.
Before it was decommissioned in 1999, it was the home of Marine Corps Aviation on the West Coast. ...
and Tustin Marine Corps Air Station) occupied 36 percent of the land area as of 2000. Residential was second, comprising 15 percent of the watershed. Other land uses are agriculture (23%), parks and open space (23%), commercial (8%), industrial (6%). The amount of agricultural and vacant land is decreasing as new residential neighborhoods are being developed around the periphery of Irvine, though on the other hand, the redevelopment of the El Toro air base as the Orange County Great Park will add to the amount of recreational land.
Streamflow
The dry-season flow of San Diego Creek consists mainly of urban
Urban means "related to a city". In that sense, the term may refer to:
* Urban area, geographical area distinct from rural areas
* Urban culture, the culture of towns and cities
Urban may also refer to:
General
* Urban (name), a list of people ...
and agricultural drainage runoff. According to the Environmental Protection Agency
A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...
, average dry-season flow at the mouth is , whereas wet-season runoff is . The average annual flow is about , per year. An all-time highest flow of was recorded on December 6, 1997.
The United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
has operated three stream gages on San Diego Creek and several on its tributaries. Mean, maximum and minimum flow for the period of record are given in the below table:
History
Before the 19th century, the San Diego Creek basin consisted of extensive grasslands and seasonal wetlands, which would flood during the winter and spring with storm runoff from the Santa Ana Mountains and San Joaquin Hills. San Diego Creek did not have a well defined channel like it does today, but rather was a series of interconnected sumps and swamps in the lower elevations of the valley. The Santa Ana River
The Santa Ana River is the largest river entirely within Southern California in the United States. It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside Counties, before cutting through ...
, the main waterway of Orange County, would sometimes flow into Newport Bay via what is now the lower part of the San Diego Creek channel. This was observed several times during the 1800s and geological evidence suggests this regularly occurred as early as the Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
period. The area was known as the "Cienega de las Ranas" (''Marsh of the Frogs'') by early Spanish settlers, for the millions of tree frogs that once inhabited the forested lowlands. Lacking a direct outlet to the sea, the water table
The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated.
T ...
in the area was rather high and resulted in many year round artesian
Artesian may refer to:
* Someone from the County of Artois
* Artesian aquifer, a source of water
* Artesian Builds, a former computer building company
* Artesian, South Dakota, United States
* Great Artesian Basin, Australia
* The Artesian Hotel ...
springs, which supported a rich variety of native plant and animal life.
Starting about 2,000 years ago, the valley was inhabited by the Gabrielino
The Tongva ( ) are an Indigenous peoples of California, Indigenous people of California from the Los Angeles Basin and the Channel Islands of California, Southern Channel Islands, an area covering approximately . Some descendants of the people p ...
(Tongva) Native Americans, who depended on the abundant game of the area for their sustenance. A major landmark for the Gabrielino was the Red Hill, located in present-day Tustin at the northern tip of the Cienega de las Ranas. The Gabrielino called it ''Katuktu'', "place of refuge". According to legend, the people had climbed the hill to escape a great flood that covered the plain in ancient times. This has basis in historical events – every few decades, during an extremely wet winter, the Santa Ana River
The Santa Ana River is the largest river entirely within Southern California in the United States. It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside Counties, before cutting through ...
and Santiago Creek
Santiago Creek is a major watercourse in Orange County in the U.S. state of California. About long, it drains most of the northern Santa Ana Mountains and is a tributary to the Santa Ana River. It is one of the longest watercourses entirely within ...
to the northwest would change their course and flood large portions of the coastal plain.
During the 18th century, the first Spanish explorers traveled through the region, followed by missionaries (''padres''), soldiers and settlers. El Camino Real was established to link the chain of missions constructed in California by the Spanish invaders. The Cienega de las Ranas was a major obstacle along the Camino Real and was completely impassable during most winters. In other seasons, those who were traveling from the south by night relied on the singing of the frogs to guide them to Red Hill (called "Cerrito de las Ranas" or ''Frog Hill'' by the Spanish), which marked the northern edge of the swamps.[ The Cienega was part of the ]Mission San Juan Capistrano
Mission San Juan Capistrano ( es, Misión San Juan Capistrano) is a Spanish mission in San Juan Capistrano, Orange County, California. Founded November 1, 1776 in colonial ''Las Californias'' by Spanish Catholic missionaries of the Franciscan O ...
lands, which encompassed most of what is now south Orange County. The Spanish used the area largely for cattle ranching, the main contributor to the mission's economy.
After Mexico became independent from Spain, it passed the Secularization Act of 1833, which repossessed the mission land holdings and distributed them to individuals as land grants or ''ranchos''. The Cienega became part of the Rancho Cienega de las Ranas, granted to José Antonio Andres Sepúlveda in 1837. The Rancho Bolsa de San Joaquin was combined with Sepúlveda's original lands in 1842 to create the Rancho San Joaquin
Rancho San Joaquin, the combined Rancho Cienega de las Ranas and Rancho Bolsa de San Joaquin, was a Mexican land grant in the San Joaquin Hills, within present-day Orange County, California.
It was granted to José Antonio Andres Sepúlveda ...
. Sepúlveda built a large adobe villa near where the present day San Diego Creek empties into Newport Bay. Shortly after California became part of the United States in 1850, a series of droughts and floods crippled the region, forcing Sepúlveda and other ''rancheros'' to sell their holdings. In 1864, portions of the Rancho San Joaquin, and the adjacent Rancho Loma de Santiago and Rancho Santiago de Santa Ana Rancho Santiago de Santa Ana was a Spanish land concession in present-day Orange County, California, given by Spanish Alta California Governor José Joaquín de Arrillaga in 1810 to Jose Antonio Yorba and his nephew Pablo Peralta. The grant exten ...
were sold to real estate investor James Irvine, one of the founders of the Irvine Ranch.
During most of the late 19th and early 20th century, the watershed was used for agriculture. Increased runoff from farmlands resulted in extensive erosion, which led to the creation of a stream channel that ran northwestwards into the Santa Ana River channel and thence the Upper Newport Bay. As siltation
Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or ...
problems plagued the bay, the Bitter Point Dam was constructed to divert the Santa Ana River to its present mouth at Huntington Beach
Huntington Beach is a seaside city in Orange County in Southern California, located southeast of Downtown Los Angeles. The city is named after American businessman Henry E. Huntington. The population was 198,711 during the 2020 census, maki ...
, leaving the Cienega/San Diego Creek as the main watercourse flowing into the bay.
To support irrigation, farmers drilled numerous wells to tap the region's abundant groundwater. However, with some 1,200 wells in operation by the 1920s, the local wetlands began to disappear as the depth to groundwater increased. Dry farming gradually replaced irrigated farming as it became more expensive to drill new deeper wells. The Irvine Ranch also imported surface water from Santiago Creek
Santiago Creek is a major watercourse in Orange County in the U.S. state of California. About long, it drains most of the northern Santa Ana Mountains and is a tributary to the Santa Ana River. It is one of the longest watercourses entirely within ...
starting in the 1930s, when it constructed Santiago Dam
Santiago Dam (also known as Santiago Creek Dam) is an earth/rockfill dam across Santiago Creek in Orange County, in the U.S. state of California, forming Irvine Lake. The earth dam and its reservoir serve for flood control and recreational purpos ...
to form Irvine Lake
Irvine Lake is a reservoir in Orange County, California, United States. It is on Santiago Creek, located in Silverado, California, east of the city of Irvine and close to Irvine Regional Park. The reservoir is currently operated by the Serrano ...
, the largest body of fresh water in Orange County. A gunite lined aqueduct diverted water from Irvine Lake to the Upper Peters Canyon Reservoir along Peters Canyon Wash, which stored water for later use on farms.
During the 1930s the area around the mouth of San Diego Creek was developed extensively for salt production, with numerous evaporating ponds in the Upper Newport Bay Salt Works. In 1932 the Irvine Conservation Dam, an earthen structure high, was built across San Diego Creek a mile (1.6 km) above the mouth, to capture storm runoff for irrigation, as well as provide flood protection to the salt works. The dam was removed in 1963. Severe flooding in 1969 destroyed the salt works and subsequent floods filled much of the bay with sediment. After a proposal to turn the area into a yacht harbor in the 1970s was thwarted by conservation groups, the bay is now a protected wetlands area.
In 1942, the Marine Corps established two air bases in the watershed. The construction of El Toro Marine Corps Air Station required the burial of a major tributary, the Agua Chinon Creek. Liquid fuel waste disposal at the site between 1942 and 1999, when the base was closed, has resulted in significant contamination of the local aquifer. The second was Marine Corps Air Station Tustin
Marine Corps Air Station Tustin (IATA: NTK, ICAO: KNTK, FAA LID: NTK) is a former United States Navy and United States Marine Corps air station, located in Tustin, California.
History
The Air Station was established in 1942 by the United ...
, an airship
An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air.
In early ...
base, which was built over the deepest part of the Cienega de las Ranas. After World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
, the San Diego Creek watershed experienced rapid urbanization. As the Irvine Company
The Irvine Company LLC is an American private company focused on real estate development. It is headquartered in Newport Beach, California, with a large portion of its operations centered in and around Irvine, California, a planned city of more ...
sought to develop the of the former Irvine Ranch
The Irvine Company LLC is an American private company focused on real estate development. It is headquartered in Newport Beach, California, with a large portion of its operations centered in and around Irvine, California, a planned city of more ...
, an ambitious effort was made to drain the former Cienega via a series of pumping plants and ditches, and later the construction of the flood control channels that today make up the San Diego Creek system.
In 2014, a cannonball believed to be of Civil War
A civil war or intrastate war is a war between organized groups within the same state (or country).
The aim of one side may be to take control of the country or a region, to achieve independence for a region, or to change government policies ...
origins was found in the creek. The Lincoln Memorial Shrine Museum in Redlands confirmed that it had been used by the Union army, but there are no records of Union troops ever passing through the area. A likely scenario is that the cannonball was lost by a contingent traveling to Riverside
Riverside may refer to:
Places Australia
* Riverside, Tasmania, a suburb of Launceston, Tasmania
Canada
* Riverside (electoral district), in the Yukon
* Riverside, Calgary, a neighbourhood in Alberta
* Riverside, Manitoba, a former rural m ...
, and washed down the Santa Ana River (which during the 1860s still flowed into Newport Bay) by floods.
San Joaquin Marsh
The San Joaquin Marsh is a long and narrow, approximately constructed wetland
A constructed wetland is an artificial wetland to treat sewage, greywater, stormwater runoff or industrial wastewater. It may also be designed for land reclamation after mining, or as a mitigation step for natural areas lost to land development. ...
that occupies the lower of the San Diego Creek stream course adjacent to the UC Irvine
UC may refer to:
Arts and entertainment
* ''University Challenge'', a popular British quiz programme airing on BBC Two
** '' University Challenge (New Zealand)'', the New Zealand version of the British programme
* Universal Century, one of the ti ...
campus. It consists of about a dozen ponds fed by San Diego Creek, which is impounded by a series of low rock dams. The marsh is located in the ancient, now abandoned bed of the Santa Ana River
The Santa Ana River is the largest river entirely within Southern California in the United States. It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside Counties, before cutting through ...
which once flowed into Upper Newport Bay. It provides habitat for about 200 bird species, including 100 migrating species and 20 nesting species. The marsh helps to clean polluted runoff in San Diego Creek before it flows into the estuary of Newport Bay. Until the early 2000s, the area was heavily contaminated with the pesticides 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 ( ...
and chlorpyrifos
Chlorpyrifos (CPS), also known as Chlorpyrifos ethyl, is an organophosphate pesticide that has been used on crops, animals, and buildings, and in other settings, to kill several pests, including insects and worms. It acts on the nervous systems ...
, which were successfully removed from the creek after the Environmental Protection Agency
A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...
implemented best management practices in the watershed.
Currently the largest freshwater marsh in Orange County, the San Joaquin was once severely polluted and degraded, having been used first as the Newport salt works and then as farmland. During the 1950s and 1960s, San Diego Creek followed a much shorter, channelized course to the bay, bypassing the marsh entirely. In 1972 the Irvine Company leased the marsh to hunting clubs, which restored the creek's original, longer course to the bay and built levee
A levee (), dike (American English), dyke (English in the Commonwealth of Nations, Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually soil, earthen and that often runs parallel (geometry), parallel to ...
s to create duck ponds. In 1988 ownership was transferred back to the Irvine Ranch Water District. Starting in 1996 large scale habitat restoration work was carried out, with restored by 1997 and a further by 2000. The old diversion channel is still in place; today, it is mainly used for flood control.
In July 2000, the City of Irvine, which owns of the marsh in the San Joaquin Wildlife Sanctuary
The San Joaquin Marsh Wildlife Sanctuary is a constructed wetland in Irvine, California, in the flood plain of San Diego Creek just above its outlet into the Upper Newport Bay.
History
The site is owned by the Irvine Ranch Water District; it ...
, contributed a further $1.5 million to its restoration, along with contributions from the Audubon Society
The National Audubon Society (Audubon; ) is an American non-profit environmental organization dedicated to conservation of birds and their habitats. Located in the United States and incorporated in 1905, Audubon is one of the oldest of such organ ...
and the State of California. The remaining belong to the University of California
The University of California (UC) is a public land-grant research university system in the U.S. state of California. The system is composed of the campuses at Berkeley, Davis, Irvine, Los Angeles, Merced, Riverside, San Diego, San Francisco, ...
and have been designated as the San Joaquin Freshwater Marsh Reserve.
Tributaries
From north to south, the named tributaries of San Diego Creek are the La Cañada Channel (flowing from Laguna Canyon
Laguna Canyon (also called Cañada de las Lagunas, meaning "Lake Canyon" in Spanish) is a canyon that cuts through the San Joaquin Hills in southern Orange County, California, in the United States, directly south of the city of Irvine. The canyo ...
), Serrano Creek Serrano Creek is a roughly tributary of San Diego Creek in the U.S. state of California. The creek starts in the Santa Ana Mountains in a canyon in Whiting Ranch Wilderness Park, near the boundary of the Cleveland National Forest. It then flows sou ...
, Agua Chinon Creek
Agua Chinon Creek or Agua Chinon Wash is an urban stream in the city of Irvine, Orange County, California. The creek flows southwest from its headwaters in the foothills of the Santa Ana Mountains for about to join San Diego Creek near the Ver ...
, Bee Canyon Wash, Como Drain, Lyon Drain, Marshburn Channel, Coyote Canyon Channel, Peters Canyon Wash
Peters Canyon Wash is a tributary of San Diego Creek in central Orange County in the U.S. state of California. About long north-south, the wash, now mostly channelized, flows in a relatively straight course southwest from the Peters Canyon Rese ...
, Barranca Channel, Lane Channel, San Joaquin Wash, Sand Canyon Wash, and Bonita Creek.[
The creek also has a few tributaries that provide the outflow for several water supply and flood control reservoirs in the San Joaquin Hills and Santa Ana Mountains. From source to mouth, these are La Cañada Channel (fed by Laguna Reservoir), Bee Canyon (two unnamed reservoirs), Peters Canyon Wash (Peters Canyon Reservoir), San Joaquin Wash (San Joaquin Reservoir) and Sand Canyon Wash (Sand Canyon and Strawberry Valley reservoirs).][
The largest sub-tributaries include Borrego Canyon Wash (to Agua Chinon Creek), Round Canyon (to Bee Canyon Wash), Santa Ana-Santa Fe Channel (to Peters Canyon) and Culver Drain (to San Joaquin Wash). There are many other ephemeral watercourses and drains in the watershed, but they are too numerous to list entirely.][
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See also
* San Diego Creek bicycle path
* List of rivers of Orange County, California
References
External links
San Diego Creek: Retrofitting a Watershed for Water Quality
{{Authority control
Rivers of Orange County, California
San Joaquin Hills
Newport Beach, California
Rivers of Southern California