Environment of California

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California is on the western coast of the United States. Map of USA CA.svg
California is on the western coast of the United States.

The environment of California describes results of human habitation of the American State of California.


History of environmental action

Gold miners excavate an eroded bluff with jets of water at a placer mine in Dutch Flat, California sometime between 1857 and 1870. Hydraulic mining in Dutch Flat, California, between 1857 and 1870.jpg
Gold miners excavate an eroded bluff with jets of water at a placer mine in Dutch Flat, California sometime between 1857 and 1870.

California's Mediterranean climate makes vegetation susceptible to wildfires through the dry summers. Aboriginal Californians used fire to control brush, promote growth of seed-producing plants important to subsistence, and perhaps as an aid to hunting wildlife. These periodic fires kept woodland areas relatively open until 20th century laws curtailed burning in an effort to protect structures. [1] European crops and livestock were introduced with missions along the coast from San Diego to San Francisco Bay through the late 18th and early 19th century. The California Gold Rush caused explosive population growth making San Francisco the only 19th century city west of St. Louis, Missouri. [2] Water soon became the limiting factor for population growth, and early laws established water rights for irrigation and hydraulic mining. The Great Flood of 1862 washed gravel displaced by gold mining downstream to cover riparian cropland and fill formerly navigable stream channels serving as transportation corridors to San Francisco Bay. The damage encouraged passage of water pollution control legislation, broadly regulating disposal of waste to include relatively innocuous materials like gravel. [3] These California laws provided a template for the United States Environmental Protection Agency National Pollutant Discharge Elimination System.

Population and transportation

20th century petroleum extraction helped the city of Los Angeles become one of the largest in the United States. Oil wells just offshore at Summerland, California, c.1915.jpg
20th century petroleum extraction helped the city of Los Angeles become one of the largest in the United States.

California's aboriginal population of about 300,000 was distributed in relatively self-sufficient groups with subsistence resources on the coastal wetlands near the mouth of the Smith River, along the Klamath River and its interior wetlands, on the coastal wetlands surrounding Humboldt Bay, on the wetlands surrounding San Francisco Bay and the rivers of the California Central Valley, along the Salinas River, and along the coastal wetlands between Morro Bay and San Diego Bay. Early European trade was by ship, but El Camino Real extended northward along the southern California coast and through the California Coast Ranges from Mexico to San Francisco Bay to link individual missions with seaports. San Francisco Bay became the most important seaport for the gold rush and ferries of San Francisco Bay carried trade between the seaport and mining areas. The California Trail became the first important land link between San Francisco Bay and the eastern United States during the gold rush and became the route of the First transcontinental railroad in 1869. The gold rush brought approximately 200,000 new residents to California, and 36% of Californians lived around San Francisco Bay by 1870. [2] Lumber from coastal redwood forests was transported to San Francisco by ships. Redwood proved poorly suited for railroad ties, so fast-growing Australian eucalypts were widely planted to provide future supplies.

San Francisco Bay remained the focus of a railway network extending north and south until Atchison, Topeka and Santa Fe Railway completed a transcontinental rail link to Los Angeles and San Diego in 1885. Eastbound rail shipment of citrus began in 1890. Petroleum was discovered in 1892, and the first offshore drilling occurred at Summerland Oil Field in 1896. [4] Hollywood's film industry and shift of the United States Navy Battle Fleet home port to San Pedro in 1919 accelerated growth of southern coastal cities to 36% of the state population by 1920. [2]

A majority of Californians live, commute, and work in the hazy web of Southern California freeways. Los Angeles - Echangeur autoroute 110 105.JPG
A majority of Californians live, commute, and work in the hazy web of Southern California freeways.

As California petroleum production peaked, the United States Highway System of 1925 included routes paralleling older transportation corridors. U.S. Route 101 followed El Camino Real and extended through the redwoods to Humboldt Bay. U.S. Route 99 extended northward from Los Angeles following railways through the Central Valley; and the Lincoln Highway and U.S. Route 66 followed the transcontinental rail routes from San Francisco Bay and Los Angeles, respectively. Popularity of automobile travel encouraged construction of California Route 1 connecting California State Beaches, U.S. Route 395 through the Sierra Nevada, and the Arroyo Seco Parkway as the first freeway. Smog was recognized as an air pollution problem in 1954 [5] as Los Angeles Railway, Pacific Electric Railway and Key System public transport facilities were dismantled during the great American streetcar scandal. Southern California cities were home to 51% of Californians when the Interstate Highway System arrived in 1959, while 26% lived around San Francisco Bay. Lincoln Highway became Interstate 80, Route 66 became Interstate 40, and Interstate 5 extended from San Diego through Los Angeles and north up the rain shadowed western side of the Central Valley and the eastern end of San Francisco Bay. [2]

Modern commuter rail service includes Bay Area Rapid Transit, Caltrain, Muni Metro, Metro Rail (Los Angeles County), San Diego Trolley, Sacramento Regional Transit District, Santa Clara Valley Transportation Authority light rail, and Amtrak's Pacific Surfliner and Capitol Corridor . In 2010, 9 million Californians (24% of the population) lived around San Francisco Bay and 21 million (57% of the population) lived in the southern coastal cities. [6]

Water transfers

The Salton Sea is an endorheic basin of evaporating irrigation return flows. Salton Sea Tilapia.jpg
The Salton Sea is an endorheic basin of evaporating irrigation return flows.

Unsuccessful gold prospectors soon recognized California's agricultural potential and their mining equipment began adjusting timing and location of stream flows to increase food production. Mono Lake and Tulare Lake shrank as flows were diverted to irrigation. [7] Little Lake was drained to form the town of Willits, California in 1874, [8] and Laguna de Santa Rosa was drained to bring rail service to Sonoma County. [9] The Klamath Project drained large shallow lakes for conversion to cropland in 1905. The Potter Valley Project diverted water from the Eel River to the Russian River in 1906 to provide hydroelectric power to Ukiah, California; and Lake Pillsbury was formed behind Scott Dam in 1922 to increase summer flows allowing irrigation of Potter Valley. [10]

California Water Wars opened with the Los Angeles Aqueduct in 1913 as the first large-scale transfer of water from northern mountains to meet population needs of southern California's coastal cities. Hetch Hetchy Aqueduct transferred water to San Francisco in 1932 after John Muir's unsuccessful efforts to preserve Yosemite National Park's Hetch Hetchy Valley. The 1922 Colorado River Compact allowed completion of the Colorado River Aqueduct to Los Angeles in 1941. [11]

U.S. Bureau of Reclamation public works projects included Friant Dam on the San Joaquin River in 1942 and Shasta Dam on the Sacramento River in 1945. These dams reduced winter flooding and summer salinity of the Sacramento-San Joaquin Delta encouraging crop production on drained wetlands. The Central Valley Project continued with Folsom Dam on the American River, Trinity Dam on the Trinity River, and Oroville Dam on the Feather River. Construction of the California Aqueduct has been completed to Southern California except for a Peripheral Canal which might restore pre-dam delta salinity concentrations. [11]

A major fraction of water transferred to southern California is used for production of food. Irrigation return flows like the New River may contain pesticides and elevated concentrations of dissolved minerals, and may accumulate in endorheic basins like Kesterson Reservoir. The Salton Sea was enlarged by diversion of water from the Colorado River. [12]

New environments

Cat eating a house sparrow. Cat-eating-prey.jpg
Cat eating a house sparrow.
Raccoon and skunk eating cat food in a Hollywood back yard Urban raccoon and skunk.JPG
Raccoon and skunk eating cat food in a Hollywood back yard

Aside from simple agricultural environments, water transfer has created a unique southern California urban area. The relatively low urban population density encouraged by automobile mobility features edge effect habitats including a broad range of landscaping plants. Omnivores able to cross streets, roads, and freeways thrive in this spatially fragmented habitat with dry season water available from landscape irrigation. Columbidae, Corvidae, house sparrow, European starling and gulls fly between isolated habitat segments, while raccoons, opossums, skunks and rats travel under bridges and through culverts and storm drains. Animals killed during unsuccessful crossing attempts are a food source for scavengers also seeking garbage or food intended for pets or wild birds and squirrels. Domestic cats and dogs kill small animals for recreation and have established feral predator populations. Coyotes prey on these smaller predators. [13]



Climate change

See also

Related Research Articles

<span class="mw-page-title-main">Sacramento River</span> River in Northern and Central California, United States

The Sacramento River is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for 400 miles (640 km) before reaching the Sacramento–San Joaquin River Delta and San Francisco Bay. The river drains about 26,500 square miles (69,000 km2) in 19 California counties, mostly within the fertile agricultural region bounded by the Coast Ranges and Sierra Nevada known as the Sacramento Valley, but also extending as far as the volcanic plateaus of Northeastern California. Historically, its watershed has reached as far north as south-central Oregon where the now, primarily, endorheic (closed) Goose Lake rarely experiences southerly outflow into the Pit River, the most northerly tributary of the Sacramento.

<span class="mw-page-title-main">Central Valley (California)</span> Flat valley that dominates central California

The Central Valley is a broad, elongated, flat valley that dominates the interior of California. It is 40–60 mi (60–100 km) wide and runs approximately 450 mi (720 km) from north-northwest to south-southeast, inland from and parallel to the Pacific coast of the state. It covers approximately 18,000 sq mi (47,000 km2), about 11% of California's land area. The valley is bounded by the Coast Ranges to the west and the Sierra Nevada to the east.

<span class="mw-page-title-main">Tulare Lake</span> Freshwater dry lake in the southern San Joaquin Valley, California, United States

Tulare Lake is a freshwater dry lake with residual wetlands and marshes in the southern San Joaquin Valley, California, United States. After Lake Cahuilla disappeared in the 17th century, Tulare Lake was the largest freshwater lake west of the Mississippi River and the second-largest freshwater lake entirely in the United States, based upon surface area. A remnant of Pleistocene-era Lake Corcoran, Tulare Lake dried up after its tributary rivers were diverted for agricultural irrigation and municipal water uses.

<span class="mw-page-title-main">Hetch Hetchy</span> Valley, reservoir, and aqueduct in California, USA

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 before the arrival of settlers from the United States in the 1850s, the valley was inhabited by Native Americans who practiced subsistence hunting-gathering. During the late 19th century, the valley was renowned for its natural beauty – often compared to that of Yosemite Valley – but also targeted for the development of water supply for irrigation and municipal interests. The controversy over damming Hetch Hetchy became mired in the political issues of the day. The law authorizing the dam passed Congress on December 7, 1913.

<span class="mw-page-title-main">San Joaquin Valley</span> Area of the Central Valley in California

The San Joaquin Valley is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven counties of Northern and one of Southern California, including, in the north, all of San Joaquin and Kings counties, most of Stanislaus, Merced, and Fresno counties, and parts of Madera and Tulare counties, along with a majority of Kern County, in Southern California. Although the valley is predominantly rural, it has densely populated urban centers: Fresno, Bakersfield, Stockton, Modesto, Tulare, Visalia, Hanford, and Merced.

<span class="mw-page-title-main">California Aqueduct</span> Water supply project

The Governor Edmund G. Brown California Aqueduct is a system of canals, tunnels, and pipelines that conveys water collected from the Sierra Nevada Mountains and valleys of Northern and Central California to Southern California. Named after California Governor Edmund Gerald "Pat" Brown Sr., the over 400-mile (640 km) aqueduct is the principal feature of the California State Water Project.

<span class="mw-page-title-main">Carquinez Strait</span> Tidal strait in Northern California

The Carquinez Strait is a narrow tidal strait in Northern California. It is part of the tidal estuary of the Sacramento and the San Joaquin rivers as they drain into the San Francisco Bay. The strait is eight miles (13 km) long and connects Suisun Bay, which receives the waters of the combined rivers, with San Pablo Bay, a northern extension of the San Francisco Bay.

<span class="mw-page-title-main">Sacramento–San Joaquin River Delta</span> Inland river delta and estuary in Northern California

The Sacramento–San Joaquin River Delta, or California Delta, is an expansive inland river delta and estuary in Northern California. The Delta is formed at the western edge of the Central Valley by the confluence of the Sacramento and San Joaquin rivers and lies just east of where the rivers enter Suisun Bay, which flows into San Francisco Bay and then the Pacific Ocean via San Pablo Bay. The Delta is recognized for protection by the California Bays and Estuaries Policy. Sacramento–San Joaquin Delta was designated a National Heritage Area on March 12, 2019. The city of Stockton is located on the San Joaquin River on the eastern edge of the delta. The total area of the Delta, including both land and water, is about 1,100 square miles (2,800 km2). Its population is around 500,000 residents.

<span class="mw-page-title-main">Colorado River Aqueduct</span> Water conveyance in Southern California

The Colorado River Aqueduct, or CRA, is a 242 mi (389 km) water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California (MWD). The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border, west across the Mojave and Colorado deserts to the east side of the Santa Ana Mountains. It is one of the primary sources of drinking water for Southern California.

<span class="mw-page-title-main">Pyramid Lake (Los Angeles County, California)</span> Reservoir in Los Angeles County, California, United States

Pyramid Lake is a reservoir formed by Pyramid Dam on Piru Creek in the eastern San Emigdio Mountains, near Castaic, Southern California. It is a part of the West Branch California Aqueduct, which is a part of the California State Water Project. Its water is fed by the system after being pumped up from the San Joaquin Valley and through the Tehachapi Mountains.

<span class="mw-page-title-main">San Gabriel River (California)</span> River in Los Angeles County, California, United States

The San Gabriel River is a mostly urban waterway flowing 58 miles (93 km) southward through Los Angeles and Orange Counties, California in the United States. It is the central of three major rivers draining the Greater Los Angeles Area, the others being the Los Angeles River and Santa Ana River. The river's watershed stretches from the rugged San Gabriel Mountains to the heavily developed San Gabriel Valley and a significant part of the Los Angeles coastal plain, emptying into the Pacific Ocean between the cities of Long Beach and Seal Beach.

<span class="mw-page-title-main">Metropolitan Water District of Southern California</span> Regional wholesaler of water in Southern California

The Metropolitan Water District of Southern California is a regional wholesaler and the largest supplier of treated water in the United States. The name is usually shortened to "Met," "Metropolitan," or "MWD." It is a cooperative of fourteen cities, eleven municipal water districts, and one county water authority, that provides water to 19 million people in a 5,200-square-mile (13,000 km2) service area. It was created by an act of the California Legislature in 1928, primarily to build and operate the Colorado River Aqueduct. Metropolitan became the first contractor to the State Water Project in 1960.

<span class="mw-page-title-main">History of California (1900–present)</span> Overview of the history of California from 1900 to today

This article continues the history of California in the years 1900 and later. For events through 1899, see History of California before 1900.

<span class="mw-page-title-main">California State Water Project</span> Flood control, energy production, and water conveyance infrastructure

The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public water and power utilities in the world, providing drinking water for more than 23 million people and generating an average of 6,500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5,100 GWh.

<span class="mw-page-title-main">Piru Creek</span> Creek in Ventura County, California

Piru Creek is a major stream, about 71 miles (114 km) long, in northern Los Angeles County and eastern Ventura County, California. It is a tributary of the Santa Clara River, the largest stream system in Southern California that is still relatively natural.

<span class="mw-page-title-main">Transportation in California</span> Overview of the transport in the State of California

California's transportation system is complex and dynamic. Although known for its car culture and extensive network of freeways and roads, the state also has a vast array of rail, sea, and air transport. Several subway, light rail, and commuter rail networks are found in many of the state's largest population centers. In addition, with the state's location on the West Coast of the United States, several important ports in California handle freight shipments from the Pacific Rim and beyond. A number of airports are also spread out across the state, ranging from small general aviation airports to large international hubs like Los Angeles International Airport and San Francisco International Airport.

The Peripheral Canal was a series of proposals starting in the 1940s to divert water from California's Sacramento River, around the periphery of the San Joaquin-Sacramento River Delta, to uses farther south. The canal would have attempted to resolve a problem with the quality of water pumped south. Pumps create such a powerful suction that the boundary between freshwater to saltwater has shifted inland, negatively affecting the environment. The pumps have increased by 5 to 7 million acre-feet the amount of water exported each year to the Central Valley and Southern California. However, the peripheral canal as proposed would have reduced the overall freshwater flow into the Delta and move the freshwater-saltwater interface further inland, causing damage to Delta agriculture and ecosystems.

<span class="mw-page-title-main">Water in California</span> Water supply and distribution in the U.S. state of California

California's interconnected water system serves over 30 million people and irrigates over 5,680,000 acres (2,300,000 ha) of farmland. As the world's largest, most productive, and potentially most controversial water system, it manages over 40 million acre-feet (49 km3) of water per year.

<span class="mw-page-title-main">San Diego Creek</span> River in California, United States

San Diego Creek is a 16-mile (26 km) urban waterway flowing into Upper Newport Bay in Orange County, California in the United States. Its watershed covers 112.2 square miles (291 km2) in parts of eight cities, including Irvine, Tustin, and Costa Mesa. From its headwaters in Laguna Woods the creek flows northwest to its confluence with Peters Canyon Wash, where it turns abruptly southwest towards the bay. Most of the creek has been converted to a concrete flood control channel, but it also provides important aquatic and riparian habitat along its course and its tidal estuary.

<span class="mw-page-title-main">O'Shaughnessy Dam (California)</span> Dam in Tuolumne County, California, United States

O'Shaughnessy Dam is a 430-foot (131 m) high concrete arch-gravity dam in Tuolumne County, California, United States. It impounds the Tuolumne River, forming the Hetch Hetchy Reservoir at the lower end of Hetch Hetchy Valley in Yosemite National Park, about 160 miles (260 km) east of San Francisco. The dam and reservoir are the source for the Hetch Hetchy Aqueduct, which provides water for over two million people in San Francisco and other municipalities of the west Bay Area. The dam is named for engineer Michael O'Shaughnessy, who oversaw its construction.


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