The Ventura River, in western
Ventura County
Ventura County () is a county in the southern part of the U.S. state of California. As of the 2020 census, the population was 843,843. The largest city is Oxnard, and the county seat is the city of Ventura.
Ventura County comprises the Oxnar ...
in
southern California
Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...
, United States, flows from its headwaters to 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 ...
. The smallest of the three major rivers in Ventura County, it flows through the steeply sloped, narrow Ventura Valley, with its final through the broader Ventura River estuary, which extends from where it crosses under a
101 Freeway bridge through to the Pacific Ocean.
Physical geography
Watershed
The Ventura River watershed encompasses consisting of steep mountains and foothills, with altitudes ranging from to sea level. Valley floors are home to communities and farms. Conditions in much of the watershed remain natural and undeveloped, with 57% of its land area in protected status. Most of the watershed's primary streams and drainages are unchannelized, though the natural hydrologic patterns have been modified by two dams (the Casitas and Matilija) and three levees (the Ventura River, Casitas Springs, and Live Oak).
[
Developed land (excluding grazing) comprises only about 13% of the total land area in the watershed. The northern half of the watershed lies within ]Los Padres National Forest
Los Padres National Forest is a United States national forest in Southern California, southern and central California. Administered by the United States Forest Service, Los Padres includes most of the mountainous land along the California coast ...
. The watershed's southern half has agriculture as the dominant land use, with irrigated citrus and avocados as the primary crops while a significant area of land is used for cattle grazing.[ The populated area includes two cities and a number of unincorporated communities. The smaller of the two cities, ]Ojai
Ojai ( ; Chumash: ''’Awhaỳ'') is a city in Ventura County, California. Located in the Ojai Valley, it is northwest of Los Angeles and east of Santa Barbara. The valley is part of the east–west trending Western Transverse Ranges and is ...
, lies entirely within the watershed, at an elevation of . Only 13% of the larger city of Ventura lies within the watershed, adjacent to the coast on the lower stretch of the Ventura River.
The population of the watershed is relatively small and the rate of growth low. The population is approximately 44,140, which represents just 5.4% of Ventura County's population (as of 2010 Census). The population is 58% white, 37% Hispanic or Latino, 2% Asian, and 3% other races. Income varies widely, and several areas qualify as disadvantaged or severely disadvantaged communities.[
]
Course
The river flows from its headwaters through to 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 ...
. The smallest of the three major rivers in Ventura County, the Ventura River's source stream is Matilija Creek
Matilija Creek ( ) is a major stream in Ventura County in the U.S. state of California. It joins with North Fork Matilija Creek to form the Ventura River. Many tributaries feed the mostly free flowing, creek,U.S. Geological Survey. National Hydro ...
, from its confluence with North Fork Matilija Creek. Matilija Creek is Ventura River's highest volume tributary, followed by San Antonio Creek, which joins the Ventura River from the east halfway to the ocean; Coyote Creek enters the river from the west about from the river mouth and Cañada Larga Creek from the east a few miles downstream. Much of the Ventura River's route is contained by the steeply sloped sides of the narrow Ventura Valley, with its final through the broader Ventura River estuary, which extends from where it crosses under a 101 Freeway bridge through to the Pacific Ocean.
Climate
Rainfall varies geographically, seasonally, and from year to year. Median annual precipitation is in the lower watershed, in the middle watershed, and in the upper watershed. However, even in the subhumid upper basin, rainfall is infrequent – falling on as few days in a year as in hot, arid Phoenix
Phoenix most often refers to:
* Phoenix (mythology), a legendary bird from ancient Greek folklore
* Phoenix, Arizona, a city in the United States
Phoenix may also refer to:
Mythology
Greek mythological figures
* Phoenix (son of Amyntor), a ...
, Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
– but when rain does fall it can be extremely heavy with totals of in a week not uncommon in the middle and upper basins. Consequently, cycles of drought and flood are the norm: as an illustration, in the main settlement of Ojai since 1906, 67 percent of the years have had less than the mean rainfall.
Many parts of the Ventura River stream network are typically dry during much of the year. Surface water readily disappears underground in some stream reaches (segments); in others, groundwater regularly feeds streamflow.[
]
Ecology
The watershed's rugged topography, largely undeveloped status, and Mediterranean climate combine to make for an area of exceptional biodiversity. It supports a diverse array of natural habitats, including grassland, coastal sage scrub
Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is w ...
, chaparral, oak woodlands and savannas; coniferous woodlands; riparian scrub, woodlands and wetlands; alluvial scrub; freshwater aquatic habitats; estuarine wetlands; and coastal cobble, dune and intertidal habitats. The Ventura River estuary, at the mouth of the Ventura River, is an exceptionally valuable wetland habitat and ecological resource in the watershed.[
The watershed is home to numerous protected species and habitats, including 137 plants and animals protected at either the federal, state, or local level. The federally endangered southern California steelhead (listed in 1997) is of particular importance, given the watershed's often dry and always variable climate.][ The steelhead found in the Ventura River are part of the Southern California Steelhead Distinct Population Segment (DPS) were listed as federally endangered. Genetic analysis of the ]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'') in the Ventura river watershed (both above and below Matilija Dam) has shown them to be of native and not hatchery stocks.
Invasive species
The watershed is challenged by invasive, non-native plants, such as giant reeds, ice plants and castor bean
''Ricinus communis'', the castor bean or castor oil plant, is a species of perennial flowering plant in the spurge family, Euphorbiaceae. It is the sole species in the monotypic genus, ''Ricinus'', and subtribe, Ricininae. The evolution of ...
, which choke out the willow
Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
s and estuary-area salt marsh
A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated ...
which normally support the native fauna.[ Plans and projects have been underway since the 1990s to restore natural features, flora and fauna to the river.
]
Water Quality
Limited land development and large areas of protected habitat in the watershed help support surface water that is relatively clean compared with more developed areas in the region. However, all of the watershed major waterbodies are on the Clean Water Act
The Clean Water Act (CWA) is the primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters; recognizing the responsibiliti ...
Section 303(d) list of impaired waterbodies. Surface waters are impaired for a number of factors, including trash, algae, water diversion/pumping, eutrophic conditions, low dissolved oxygen, nitrogen, fish barriers, coliform, bacteria, mercury, and total dissolved solids.[
The estuary has been on the Clean Water Act 303(d) list for trash impairment for 10+ years. In 2008 the Los Angeles Regional Water Quality Control Board adopted the Ventura River Estuary Trash Total Maximum Daily Load (TMDL) to address the impairment and establish time schedule orders to improve water quality in this segment of the watershed.
The installation of stormwater treatment devices for the Ventura Freeway crossing was included in funding from the 2021 federal ]Infrastructure Investment and Jobs Act
The Infrastructure Investment and Jobs Act (IIJA), also known as the Bipartisan Infrastructure Bill and originally in the House as the INVEST in America ActH.R. 3684, is a United States federal statute enacted by the 117th United States Congress ...
.
History
A USA Petrochem petroleum refinery, situated within the 100-year floodplain of the river, was shutdown in 1985. In August 2012 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 ...
(EPA) determined there had been discharge to navigable waters of the United States in violation of the Clean Water Act
The Clean Water Act (CWA) is the primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters; recognizing the responsibiliti ...
. The EPA's site assessment found that there were numerous leaking pipelines, leaking tanks and leaking production vessels throughout the abandoned property. The site was also out of compliance with Los Angeles Water Quality Control Board's Ventura River Estuary Trash Total Maximum Daily Load. The EPA issued an order that the site must be cleaned up or daily fines would be sought from the owner. In 2015, the site owner agreed to remove all machinery and equipment, which would complete the cleanup of the plant.
Flooding
Rainfall in the Matilija Wilderness
The Matilija Wilderness is a wilderness area in Ventura and Santa Barbara Counties, Southern California. It is managed by the U.S. Forest Service, being situated within the Ojai Ranger District of the Los Padres National Forest. It is locate ...
, the river's headwaters, is the highest in Ventura County, with average annual rainfall that is over twice that of rainfall at the coast. The steep terrain of the Ventura River watershed, coupled with intense downpours that can occur in its upper portions, result in flash flood conditions where floodwaters rise and fall in a matter of hours. Major or moderate floods have occurred once every five years on average since 1933.
The most damaging flood recorded in the Ventura River watershed occurred in 1969. The watershed above Ojai received of rain in nine days in January. The floodwaters and associated debris flooded homes in Casitas Springs and Live Oak Acres. Much agricultural land, primarily citrus groves, was seriously damaged or destroyed. All over Ventura County, transportation facilities, including roads, bridges, and railroad tracks, were damaged. The wastewater treatment plant below Foster Park was severely damaged and dumped raw sewage into the Ventura River. In addition, sewer trunk lines were broken along the Ventura River and San Antonio Creek. Untreated sewage polluted the river and beach. The capacity of the Matilija reservoir was significantly reduced by siltation from the flood.[
]
Modifications
Water Supply
Unlike almost all of its neighbors in southern California, Ventura River watershed is 100% dependent on local water supplies. Lake Casitas serves as the major surface water supply reservoir in the watershed and groundwater is heavily relied upon. On average, surface water comprises about 55% of the water recovered from the watershed and groundwater comprises about 45%.[
Cycles of drought and flooding occur regularly. Annual rainfall in downtown Ojai has ranged from a low of seven inches to a high of 49 inches—a sevenfold variation. Because the annual amount of rainfall received is highly variable, water supplies must be managed with caution.][
Two small coastal watersheds—the North Ventura Coastal Streams watershed and the Buenaventura watershed—flank the Ventura River watershed's lower section and are dependent on its water. Water from the Ventura River watershed is used to irrigate avocado orchards in the North Ventura Coastal Streams watershed and serves a significant population within the City of Ventura.]
Legal actions
Santa Barbara Channelkeeper filed a lawsuit in 2014 alleging the city of Ventura was taking too much water from the river, hurting habitat for steelhead trout and other wildlife. The city filed a cross-complaint in response to bring in other users of the river, including the Casitas Municipal Water District. Mediation talks began among major users of the Ventura River.
Dams
The flow of the Ventura River and its tributary Coyote Creek have been reduced by the completion of Casitas Dam
Casitas Dam is an earthfill dam across Coyote Creek that forms Lake Casitas in Ventura County, California near Oak View, California. The dam is located two miles (3 km) above the junction of Coyote Creek and the Ventura River. Water from th ...
, which forms Casitas Reservoir
Lake Casitas is a reservoir in Ventura County, California, built by the United States Bureau of Reclamation and completed in 1959. The project provides drinking water and water for irrigation. A secondary benefit is flood control. It was the ven ...
. The dam is on Coyote Creek about 2 miles upstream of the junction with the Ventura River. The Robles Diversion Dam was constructed on the Ventura River in 1958 to divert up to 107,800 acre-feet of water per year through a four-and-a-half mile canal to Casitas Reservoir. About 40% of the total water in Lake Casitas is supplied from high winter flows in the Ventura River. Casitas Municipal Water District sells water to both domestic and agricultural customers.
The Matilija Creek, source stream and main tributary of the Ventura River, is controlled by the Matilija Dam
Matilija Dam is a concrete arch dam in Ventura County, California, completed in 1947. Designed for water storage and flood control, it impounds Matilija Creek to create the Matilija Reservoir in the Los Padres National Forest, south of the Matil ...
. Completed in 1948, it was built to store of water, but sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...
has reduced its capacity by 90%. The Matilija Dam was built by Ventura County, against the advice of the , who pointed out that the characteristics of waterways in the region would lead to sediment buildup, rendering the dam ineffective and dangerous.
A major project underway to remove the Matilija Dam, in part to return access to the steelhead to spawning habitat while also enhancing the overall watershed. Since 1998, efforts to remove the dam have received regulatory approvals but little funding, with one ceremonial section last removed in 2001.[
]
Management
The river bottom and adjacent land is protected by the Ojai Valley Land Conservancy (OVLC), the Ventura Land Trust, Ventura County Watershed Protection District, Ventura County Parks, and the City of Ventura. The Ventura River Preserve, owned by the OVLC, protects of land in and adjacent to the river, including of the river.[
The Ventura River Watershed Council, which includes government agencies, nonprofit groups, businesses, community groups, and individuals, prepared a watershed management plan. Approved in 2015, this comprehensive plan proposed ways to improve the health and sustainability of the watershed.
Camping in the Ventura River bottom, which is dry most of the year, was outlawed by the Ventura City Council in 1995 after floods killed one man and prompted the evacuation of 12 other people near the Main Street bridge.][McDonald, Jeff (July 09, 1995]
"Ventura River Area Gets a 2nd Chance : Environment: Ambitious $754,000 cleanup plan calls for clearing site of harmful invasive vegetation, renewing trails and diverting flood-control channels."
''Los Angeles Times
The ''Los Angeles Times'' (abbreviated as ''LA Times'') is a daily newspaper that started publishing in Los Angeles in 1881. Based in the LA-adjacent suburb of El Segundo since 2018, it is the sixth-largest newspaper by circulation in the Un ...
''
Recreation
The Ventura River Parkway Trail
The Ventura River Parkway Trail is a southern California rail trail along the Ventura River in Ventura County. Roughly paralleling California State Route 33 for from Ventura to Ojai, it follows the route of the former Ventura and Ojai Valley ...
was built on an abandoned railroad spur (CA_VEN-1109H) that was constructed by the Ventura and Ojai Valley Railroad
The Ventura and Ojai Valley Railroad gave Ojai, California, a connection to the national rail network Pacific Coast Line at Ventura Junction. Ventura Junction was located at Southern Pacific Railroad milepost (MP) 397.3 a short distance west of ...
in 1898 and acquired by Southern Pacific
The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the ...
in 1899. The rail trail
A rail trail is a shared-use path on railway right of way. Rail trails are typically constructed after a railway has been abandoned and the track has been removed, but may also share the right of way with active railways, light rail, or streetcar ...
, that runs along the easterly bank of the river, was designated a National Recreation Trail
The National Trails System is a series of trails in the United States designated "to promote the preservation of, public access to, travel within, and enjoyment and appreciation of the open-air, outdoor areas and historic resources of the Nati ...
in 2014. The "Ventura River Trail" part of the trail (completed in 1999) extends from the coast to Foster Park, and the "Ojai Valley Trail" part (completed in 1987) extends from Foster Park into the City of Ojai. The , with the steady grade of the former Southern Pacific Railway right-of-way, is very popular with bicyclists, as well as walkers and horseback riders (on the Ojai Valley Trail segment). , the vision of a "Ventura River Parkway," a network of trails, vista points, and natural areas along the river, is being actively pursued by a coalition of stakeholders.
State Route 33 also roughly parallels the river through the Ventura River Valley. A portion of SR 33, north of the SR 150, is officially designated as a state scenic highway, and the entire Ventura River Valley section is eligible for the designation.[CA Codes (shc:263.3)](_blank)
/ref>
The watershed is a recreation destination for hikers, walkers, bikers, surfers, campers, fishermen, boaters, backpackers, equestrians, and birders, as well as artists, spiritual seekers, and students of natural history. Many local organizations are committed to providing the public with access to nature and nature-based recreation opportunities.
See also
*Riparian zone restoration
Riparian-zone restoration is the ecological restoration of riparian-zone habitats of streams, rivers, springs, lakes, floodplains, and other hydrologic ecologies. A riparian zone or riparian area is the interface between land and a river or stre ...
*List of rivers of California
This is a list of rivers in the U.S. state of California, grouped by region. Major lakes and reservoirs, if applicable, are indicated in italics.
North Coast (north of Humboldt Bay)
Rivers and streams between the Oregon border and Humboldt Bay th ...
*San Buenaventura Mission Aqueduct
The San Buenaventura Mission Aqueduct was a seven-mile long, stone and mortar aqueduct built in the late 18th and/or early 19th century to transport water from the Ventura River to the Mission San Buenaventura in Ventura, California.
Accounts v ...
References
External links
* Friends of the River
**
*
Matilija Dam
* Ojai Valley Land Conservancy
*
Ventura River Confluence
*
Ventura River Preserve
*
Ventura River Steelhead Preserve
* Santa Barbara Channelkeeper
**
*
Stream Team: Ventura River
United States Bureau of Reclamation - Ventura River Project
{{Authority control
Rivers of Ventura County, California
Los Padres National Forest
Topatopa Mountains
Ojai, California
Ventura, California
Rivers of Southern California