, near
Sylmar. The only way California can support its extensive population and agriculture is to store water in numerous reservoirs and use pipes, tunnels, pumps and canals to distribute it where it is needed when it is needed. Beginning before 1900, California has built extensive water projects costing many billions of dollars to store and move water where it is needed. California water comes primarily from snowfall in the
Sierra Nevada in the northern part of the state during the relatively short winter from about October to March. The rest of the year typically has very little rainfall or snowfall. California weather is also prone to extended
droughts that can last several years. During an average rainfall year, about 14% of the power used in California is generated by hydroelectricity.
Los Angeles Aqueduct The
Los Angeles Aqueduct runs from the
Owens Valley, through the
Mojave Desert and its
Antelope Valley, to dry Los Angeles far to the south. The aqueduct project began in 1905 when the people of Los Angeles approved a million
bond for the "purchase of lands and water and the inauguration of work on the aqueduct". On June 12, 1907, a second bond was passed with a budget of million to fund the project. Construction began in 1908 and finished in 1913 while employing 5,000 workers during that period. The Los Angeles aqueduct as originally constructed consisted of six storage reservoirs and of conduit. Beginning north of Black Rock Springs, the aqueduct diverts the
Owens River into an unlined canal to begin its journey south to the Lower San Fernando Reservoir. This reservoir was later renamed the
Lower Van Norman Reservoir. Creeks flowing from the eastern Sierra are diverted into the aqueduct. The original project consisted of of open unlined canal, of lined open canal, of covered concrete conduit, of concrete tunnels, and of steel siphons. To build it required of railroad track, two hydroelectric plants, three cement plants, of power lines, of telephone line, and of roads. It was later expanded with the construction of the Mono Extension and the Second Los Angeles Aqueduct. The Los Angeles Aqueduct uses
gravity alone to move water and to generate electricity, so it is cost-efficient to operate. Finished in 1911, the Los Angeles Aqueduct was the brain-child of the self-taught engineer
William Mulholland and is still in use today.
Hetch Hetchy Hetch Hetchy is a valley that lies in the northwestern part of
Yosemite National Park and is drained by the
Tuolumne River. Starting in about 1901,
San Francisco started looking for a new supply of municipal water. Following the disastrous
1906 San Francisco earthquake and fire, this search intensified, and they finally chose the Tuolumne River as the "best" available water resource. The City and County of San Francisco bought most of the water rights to the Tuolumne River watershed in 1910. The Hetch Hetchy project centered on damming the main Tuolumne River as it meandered through Hetch Hetchy's wide glacial-cut valley. The river, with its source in a perpetual glacier on
Mount Lyell, drains of watershed of the rugged granite mountains sloping west from the Sierra Nevada crest. The Hetch Hetchy water system's goal was providing up to of water per day to San Francisco and the growing
Bay Region and tap the hydroelectric power that would be generated by a dam and power stations. After a vigorous debate, the United States Congress passed the
Raker Act in 1913 which authorized the building of dam(s), hydroelectricity plant and municipal water supply system inside part of Yosemite National Park. The act was signed by President
Woodrow Wilson in February 1916. A key element of the plan was a new dam and reservoir in the Hetch Hetchy Valley, but access to the area was poor, so a railroad was planned to help build the dam. The steep terrain dictated a 4-degree roadbed, roughly twice as steep as a "regular" railroad. The steep grades dictated geared-down locomotives. The first of the
Hetch Hetchy Railroad (HHRR) were completed in 1915, and the remaining were completed by October 1917. Construction costs for the HHRR were about US$3 million, far less than what the city might have paid contractors to transport workers, concrete and other materials for the dam over the rough and steep terrain by 12 mule train wagons. The president of the railroad was San Francisco Mayor James Rolph, and the vice president and general manager was the construction project's chief engineer
Michael O'Shaughnessy. The Hetch Hetchy Railroad was begun as a connection of the
Sierra Railway at Hetch Hetchy Junction, west of
Jamestown, and extended another to the Hetch Hetchy Dam (later named the
O'Shaughnessy Dam after the chief engineer) site for delivery of construction workers and materials. The regular trains were supplemented by trucks converted to run on the tracks to carry unscheduled loads of men or supplies or evacuate ambulance patients. The railroad was dismantled and part of its road bed converted into a highway after the Michael O'Shaughnessy dam was completed, and the new
Don Pedro Reservoir built in 1971 flooded part of the original track line. across
Hetch Hetchy Valley was initially completed in May 1923 and was raised higher to its height in 1939. The vast Hetch Hetchy Project undertaking created the
Hetch Hetchy Reservoir, miles of tunnels, and a aqueduct to deliver the water and power lines to deliver electricity to the Bay Area. Of the many dams, reservoirs, and power plants, three were in the high country of
Tuolumne County. The main dam was built in two phases. Large pipes called
penstocks channeled water down the mountain to the main Moccasin Power hydroelectric plant completed in 1925 and rebuilt in 1968. In 1923, the O'Shaughnessy Dam was completed to its initial height on the Tuolumne River, creating the Hetch Hetchy Reservoir. The dam was raised higher to its present height in 1939. The dam and reservoir are the centerpiece of the Hetch Hetchy Project, which in 1934 began to deliver water west to San Francisco and its client municipalities in the greater San Francisco Bay Area.
Central Valley Project stores using the
Trinity Dam across the
Trinity River in northern California.
Trinity Dam was the main storage feature of the
Central Valley Project (CVP) proposal to divert water from the
Trinity River in northwestern California to augment water supplies in the CVP service area. In 1948, the
U.S. Bureau of Reclamation, which was responsible for the construction and operations of most CVP facilities, devised a plan of four dams and two tunnels to capture and store some of the flow of the Trinity River and transport it to the
Sacramento River, generating a net surplus of hydroelectric power along the way.
Trinity Dam was the main storage feature of the division, providing a stable flow to the
Lewiston Dam, the diversion point for Trinity River waters into the Central Valley via the Trinity Tunnel. Trinity Lake was completely filled with water from the Trinity River by 1963, becoming the third largest lake in California, with of shoreline. across the
Sacramento River holds back the
Shasta Lake.
Shasta Dam is a concrete arch-
gravity dam across the
Sacramento River in the northern part of California, at the north end of the
Sacramento Valley. The dam mainly serves long-term water storage and flood control in its reservoir,
Shasta Lake. The lake has of mostly steep mountainous shoreline covered with tall evergreen trees and
manzanita. The lake's maximum depth is . Water released from the lake generates hydroelectric power. At high, the dam is the
ninth-tallest dam in the United States and forms the largest reservoir in California. Shasta Dam was envisioned as early as 1919 because of frequent floods and droughts troubling California's largest agricultural region, the
Central Valley. Shasta Dam was first authorized in the 1930s as a state undertaking. However, this coincided with the
Great Depression, and building of the dam was transferred to the federal
Bureau of Reclamation as a public works project. Construction started in earnest in 1937 under the supervision of Chief Engineer
Frank Crowe. During its building, the dam provided thousands of much-needed jobs; it was finished 26 months ahead of schedule in 1945. When completed, the dam was the second-tallest in the United States after
Hoover, and was considered one of the greatest engineering feats of all time. Even before its dedication, Shasta Dam served an important role in World War II, providing electricity to California factories, and it still plays a vital part in the management of state water resources. However, it has brought about major changes to the environment and ecology of the Sacramento River, and met with controversy over its significant destruction of
Native American tribal lands. In recent years, there has been debate over whether or not to raise the dam in order to allow for increased water storage and hydropower generation.
Pardee Dam is a structure across the
Mokelumne River on the boundary between
Amador and
Calaveras counties, in the foothills of the
Sierra Nevada approximately northeast of
Stockton. The Pardee Reservoir impounds of water when it is full. Construction on the Mokelumne Aqueduct and Pardee Dam began in 1926, and by 1929 the concrete arch
Pardee Dam and the First Mokelumne Aqueduct, consisting of a single pipeline, were completed. The first deliveries to the Bay Area from the reservoir were made on June 23, 1929. At the time of completion, Pardee Dam was the tallest in the world (this record was surpassed one year later by
Diablo Dam in
Washington). In 1949, a second pipeline was built, and in 1963 the third pipeline was constructed, bringing the aqueduct to its present capacity. In 1964, the second major dam and reservoir on the Mokelumne River, the
Camanche Dam and
Camanche Reservoir, were completed below Pardee. The
Mokelumne Aqueduct and dam(s)
, run by the
East Bay Municipal Utility District (EBMUD), is the primary water source for 35 communities in
Alameda and
Contra Costa counties, including
Berkeley and
Oakland. EBMUD holds water rights to almost all of the in the Mokelumne River watershed and in other watersheds. EBMUD also has an
American River water right that could be sent to the Mokelumne Aqueduct through the Folsom South Canal. (left) and the
California Aqueduct (right) near
Tracy. The
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. The
Department of Water Resources (DWR) operates and maintains the California Aqueduct, including the two largest
pumped-storage hydroelectric plants in California,
Castaic and
Gianelli. Gianelli is located at the base of
San Luis Dam, which forms
San Luis Reservoir, the largest off-stream
reservoir in the United States. The Castaic Power Plant is located at the northern end of
Castaic Lake, while
Castaic Dam is located at the southern end. The aqueduct begins at the
Sacramento–San Joaquin River Delta at the
Banks Pumping Plant, which pumps from the
Clifton Court Forebay. Water is pumped by the Banks Pumping Plant to the
Bethany Reservoir, which serves as a forebay for the
South Bay Aqueduct via the
South Bay Pumping Plant. From the Bethany Reservoir, the aqueduct flows by gravity approximately to the
O'Neill Forebay at the
San Luis Reservoir. From the O'Neill Forebay, it flows approximately to the
Dos Amigos Pumping Plant. After Dos Amigos, the aqueduct flows about to where the
Coastal Branch splits from the "main line". The split is approximately south-southeast of
Kettleman City. After the Coastal Branch, the line continues by gravity another to the Buena Vista Pumping Plant. From the Buena Vista, it flows approximately to the Teerink Pumping Plant. After Teerink it flows about to the Chrisman Pumping Plant. Chrisman is the last pumping plant before the
Edmonston Pumping Plant, which is from Chrisman. South of the plant the west branch splits off in a southwesterly direction to serve the
Los Angeles Basin. At the Edmonston Pumping Plant it is pumped over the
Tehachapi Mountains. Water flows through the aqueduct in a series of abrupt rises and gradual falls. The water flows down a long segment, built at a slight grade, and arrives at a pumping station powered by
Path 66 or
Path 15. The pumping station raises the water, where it again gradually flows downhill to the next station. However, where there are substantial drops, the water's
potential energy is recaptured by hydroelectric plants. The initial pumping station fed by the Sacramento River Delta raises the water , while a series of pumps culminating at the Edmonston Pumping Plant raises the water over the Tehachapi Mountains. The Edmonston Pumping station requires so much power that several
power lines off Path 15 and
Path 26 are needed to ensure proper operation of the pumps. A typical section has a
concrete-lined channel at the base and an average water depth of about . The widest section of the aqueduct is , and the deepest is . Channel capacity is , and the largest pumping plant capacity at Dos Amigos is . , at is the highest
embankment dam in the U.S., and at
Lake Oroville is 60% of the SWP's total water storage capacity. It is located on the
Feather River. The
California State Water Project, commonly known as the
SWP, is a
water management project under the supervision of the
California Department of Water Resources. The SWP is the world's largest publicly built and operated water and power development and conveyance system, providing drinking water for more than 23 million people and generating an average of 6,500
GWh of hydroelectricity annually. However, as the largest single consumer of power in the state, its net output in an "average" rainfall year is 5,100 GWh. The SWP collects water from rivers in northern California and redistributes it to the water-scarce but populous south through a network of aqueducts, pumping stations and hydroelectric plants. About 70% of the water provided by the project is used for urban areas and industry in
southern California and the San Francisco Bay Area, and 30% is used for
irrigation in the
Central Valley. To reach southern California, the water must be pumped over the
Tehachapi Mountains—the highest single water lift in the world. The SWP shares many facilities with the federal
Central Valley Project (CVP), which primarily serves agricultural users. Water can be interchanged between SWP and CVP canals as needed to meet peak requirements for project constituents. The SWP provides estimated annual benefits of $400 billion to California's economy. Since its inception in 1960, the SWP has required the construction of 21 dams and more than of canals, pipelines and tunnels, although these constitute only a fraction of the facilities originally proposed. As a result, the project has only delivered an average of annually, as compared to total entitlements of . Environmental concerns caused by the dry-season removal of water from the
Sacramento–San Joaquin River Delta, a sensitive
estuary region, have often led to further reductions in water delivery. Work continues today to expand the SWP's water delivery capacity while finding solutions for the environmental impacts of water diversion. on
Lake Havasu, where
Colorado River waters are initially drawn into the
Colorado River Aqueduct water distribution system. The
Colorado River Aqueduct, or
CRA, is a water conveyance in southern California, 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. This water is then transferred west by pumping stations, reservoirs, and canals 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. Originally conceived by
William Mulholland and designed by Chief Engineer Frank E. Weymouth of the MWD, it was the largest public works project in southern California during the
Great Depression. The project employed 30,000 people over an eight-year period and as many as 10,000 at one time. The system is composed of two reservoirs, five pumping stations, of canals, of tunnels, and of buried conduit and siphons. Average annual throughput is . The stated goal is the recycling of of treated municipal wastewater. On March 14, 2014, the State Water Board approved $800 million in financial incentives for recycled water projects. These projects typically take years to get approved and built. The Water Replenishment District of Southern California (WRD), in service since 1959, is one of the more aggressive agencies that use recycled water for their groundwater replenishment and seawater intrusion barriers. To prevent seawater contamination of their groundwater, they have several sets of
injection wells that inject clean water between their
aquifer and the sea. This creates a local water barrier to seawater intrusion. The other mechanism is to make sure the water level is above sea level. Well users, including municipal water users, in the WRD area pump about of water per year out of their aquifer. This is an "overdraft" of about of water over what their underground aquifer can "normally" refill. To replace this "overdraft" of water into the aquifer, they have flotation ponds that catch rain runoff water, and supplement with other water they either buy or recycle, then let the water soak into the ground (spreading water) to help replenish the water in the aquifer(s). In addition they buy
Colorado River water that is shipped via the
Colorado River Aqueduct, and they accept part of the treated municipal wastewater of the about 4,000,000 people in their district and treat it to additional purity and sanitation levels by using
reverse osmosis and advanced filtering. Their largest
tertiary water treatment facility is the Leo J. Vander Lans Advanced Water Treatment facility. The water out of this facility is better than the water that comes out of the "average" municipal water treatment facility. To finance their water recycling projects WRD charges $268 per acre-foot of water pumped out, which generates about $65,000,000/year. WRD is now on a project (WIN) to enlarge their water treatment facilities to take larger quantities of treated municipal wastewater and treat enough of it that they will not have to buy Colorado River water. Overall it is estimated that this project provides over 40% of the water used in the southern California district served by the WRD. Among the many water recycling projects just being completed, the
South Bay Water Recycling program distributes recycled water to more than 400 customers in the San Jose, area for irrigation, industrial and other purposes. In northern California, two agencies have teamed up to develop the San Ramon Valley Recycled Water Program. Jointly sponsored by the Dublin San Ramon Services District and the East Bay Municipal Utility District, the program will provide recycled water to municipal parks, golf courses, business parks, greenbelts and roadways. The Irvine Ranch Water District has built a dual water system, which supplies recycled water to commercial high rises for use in flushing toilets and urinals. A West Basin Municipal Water District project distributes recycled water to more than 85 customers, including
Chevron and
Mobil refineries. Monterey County Water Recycling Projects provide recycled water for agricultural irrigation to help ease demands on an overused groundwater aquifer. The Padre Dam Water Recycling Facility was expanded to recycle 2 million gallons/day for turf irrigation at parks, golf courses and other commercial and industrial facilities. In the
San Diego region, 16 water agencies are planning to use over of recycled water per year in order to meet the region's water supply demand. The city of
Carlsbad's new recycled water treatment and distribution system will deliver approximately per year of recycled water to customers located in that community. In the southern portion of
San Diego County, the Otay Water District is constructing a distribution system to deliver an estimated per year of recycled water by 2030 purchased from the city of San Diego's South Bay Water Recycling Plant. In southern California, the Elsinore Valley Municipal Water District is using recycled water to help replenish and enhance
Lake Elsinore. The
Orange County Sanitation and
Orange County Water Districts are planning for treated wastewater, currently discharged into the ocean, to undergo
microfiltration,
reverse osmosis and
ultraviolet disinfection. The purified water will be equivalent in quality to distilled water and exceed all state and federal drinking water standards. The purified water will be pumped to spreading ponds near the
Santa Ana River for
percolation into the groundwater basin, with some injected through injection wells along the coast as a barrier to seawater intrusion. Like the WRD projects in southern California, the
Orange County Water District has amassed a long record of successfully recycling water with its Water Factory 21.
Desalination projects On December 24, 2012, the San Diego County Water Authority announced they had sold $734 million worth of tax-free bonds at 4.38% interest to build the
Carlsbad Seawater Desalination Project, the largest seawater
desalination plant in the
Western Hemisphere. The project is located near
Encina Power Station in
Carlsbad, and is expected to produce about of water per year by 2016 when the project is completed. The plant is expected to use over 17,000 reverse osmosis racks. The project includes $80 million in San Diego Water Authority upgrades to its own facilities. A pipeline is being built to deliver desalinated water into its Twin Oaks Valley Water Treatment Plant near
San Marcos. The developer Poseidon Resources is building the plant and pipeline in a
joint venture with contractor Kiewit Shea Desalination. The project will deliver up to 50 million gallons a day of drought-proof, highly reliable water that will become a core, day-to-day resource for the region. It is projected to meet about 7% of San Diego County's demand in 2020. The total cost is projected at $1,849 to $2,257 per acre-foot. The additional cost of desalinating seawater will add $5 to $7 per month to ratepayers' bills—about a 10% increase. Poseidon has also proposed the
Huntington Beach Desalination Plant. The
2014 drought has brought reconsideration of the Charles Meyer Desalination Facility that was built for $34 million in the early 1990s in
Santa Barbara but was later essentially mothballed when the drought was over. There are early discussions about investing around $20 million more to upgrade and restart the desalination plant. They have permits to make about of desalinated water per year, but they will incur additional costs to pump their desalinated water to existing higher elevation reservoirs if they reactivate the plant. The projected costs (2014) were about $3,000 per acre foot. The small city of
Sand City, located on the
Monterey Peninsula, struck out on its own in 2007 to develop a small desalination plant. The city partnered with California American Water for the $14 million project, which started producing 300 acre feet of freshwater a year in 2010. The cost and water are shared with other nearby small communities.
California Department of Water Resource data The web site run by the California Department of Water Resources lists the present reservoir storage levels for each of California's major reservoirs. Individual reservoir capacities and percent of full are given for the major reservoirs. As of April 3, 2014, they had of water stored, or about 65% of the of water they usually would have at that time of year. ==California's highway system==