The
Colorado River Aqueduct is a water conveyance in
Southern CaliforniaSouthern California, or SoCal, is defined as the southern portion of the U.S. state of California. Its population centers around three major metropolitan areas, each of which have over 3 million people; the Los Angeles Metropolitan Area with over 12 million inhabitants, the San Bernardino-Riverside...
in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
, operated by the
Metropolitan Water District of Southern CaliforniaThe Metropolitan Water District of Southern California is the largest supplier of treated water in the US. The name is usually shortened to the "Metropolitan Water District" or simply "MWD". It is a cooperative of 14 cities and 12 municipal water districts that indirectly provides water to 18...
(MWD). The aqueduct impounds water from the Colorado River at
Lake HavasuLake Havasu is a large reservoir behind Parker Dam on the Colorado River, on the border between California and Arizona. Lake Havasu City sits on the lake's eastern shore. The lake has a capacity of . The concrete arch dam was built by the United States Bureau of Reclamation between 1934 and 1938...
on the California-
ArizonaThe State of Arizona is a state located in the southwestern region of the United States. The capital and largest city is Phoenix. The second largest city is Tucson, followed in size by the four Phoenix metropolitan area cities of Mesa, Glendale, Chandler, and Scottsdale.Arizona was the 48th and...
border west across the
MojaveThe Mojave Desert , , locally referred to as the High Desert, occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, southwestern Utah and northwestern Arizona, in the United States...
and
ColoradoCalifornia's Colorado Desert is a part of the larger Sonoran Desert, which extends across southwest North America. The Colorado Desert region encompasses approximately 7 million acres, reaching from the Mexican border in the south to the higher-elevation Mojave Desert in the north and from the...
deserts to the east side of the
Santa Ana MountainsThe Santa Ana Mountains are a short peninsular mountain range along the coast of Southern California in the United States. They extend for approximately 35 mi southeast of the Los Angeles Basin largely along the border between Orange and Riverside counties.- Geography :The range starts in the...
. It is one of the primary sources of
drinking waterDrinking water or potable water is water of sufficiently high quality that it can be consumed or used without risk of immediate or long term harm...
for Southern California.
Description
The aqueduct begins near
Parker DamParker Dam is a concrete arch-gravity dam that crosses the Colorado River downstream of Hoover Dam. It is high, of which are below the riverbed, making it the deepest, dam in the world. The dam's primary functions are to act as a reservoir, and to generate hydroelectric power. The dam straddles...
on the Colorado southeast of
Lake Havasu City, ArizonaLake Havasu City is a city in Mohave County, Arizona, United States. According to 2006 Census Bureau estimates, the population of the town is 56,355. It was founded in 1964 on the shores of Lake Havasu.-History:...
. It crosses the southern Mojave Desert, skirting around several small mountain ranges and the southern edge of
Joshua Tree National ParkJoshua Tree National Park is located in southeastern California. Declared a U.S. National Park in 1994 when the US Congress passed the California Desert Protection Act , it had previously been a U.S. National Monument since 1936. It covers a land area of . A large part of the park is designated to...
. It enters the
Coachella ValleyThe Coachella Valley is a large valley landform in Southern California. Populated by nearly one million people, the valley is part of the 14th largest metropolitan area in the United States, the Inland Empire, and includes the famed tourist destination, Palm Springs...
north of the
Salton SeaThe Salton Sea is a saline, endorheic rift lake located directly on the San Andreas Fault. The lake occupies the lowest elevations of the Salton Sink in the Colorado Desert of Riverside and Imperial Counties in Southern California. Like Death Valley, it is located below sea level, with the current...
and flows northwest along the
Little San Bernardino MountainsThe Little San Bernardino Mountains are short peninsular range in southern California in the United States. They extend for approximately 40 mi southeast from the San Bernardino Mountains through San Bernardino and Riverside counties to the northeast edge of the Salton Sea. The range separates the...
. It crosses the
San Jacinto MountainsThe San Jacinto Mountains are a mountain range east of Los Angeles in southern California in the United States. The mountains are named for Saint Hyacinth...
west of
Palm SpringsPalm Springs is a desert city in Riverside County, California, approximately 111 miles east of Los Angeles and 136 miles northeast of San Diego. As of the 2000 census, the city population was 42,807. Golf, swimming, tennis, horseback riding and hiking in the nearby desert and mountain areas are...
and terminates at
Lake MathewsLake Mathews is a large reservoir in Riverside County, California, located in the foothills of the Santa Ana Mountains. It is the western terminus for the Colorado River Aqueduct that provides much of the water used by the cities and water districts of the Metropolitan Water District of Southern...
in western
Riverside CountyRiverside County is a county located in the southeastern part of the U.S. state of California, stretching from Orange County to the Colorado River, which forms the border with Arizona...
, from whence it is distributed to multiple communities in the MWD region.
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
aqueductAn aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....
was constructed between 1933-1941 by the MWD to bring water to the 13 cities in the south coast basin that were founding member agencies of MWD. (MWD's service area now extends from Ventura county to San Diego county.) Water first flowed in the aqueduct on January 7, 1939 when the intake pumps at
Lake HavasuLake Havasu is a large reservoir behind Parker Dam on the Colorado River, on the border between California and Arizona. Lake Havasu City sits on the lake's eastern shore. The lake has a capacity of . The concrete arch dam was built by the United States Bureau of Reclamation between 1934 and 1938...
began operation to fill the first of the reservoirs in the system in Gene Basin.
Originally conceived by
William MulhollandWilliam Mulholland was the head of Los Angeles Department of Water and Power, Los Angeles in Southern California, United States...
and designed by Chief Engineer Frank E. Weymouth of the MWD, it was the largest public works project in southern California during the
Great DepressionThe Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...
. The project employed 30,000 people over an eight-year period and as many as 10,000 at one time.
The CRA contributed to urban growth (even sprawl) in the south coast region. Although the CRA brought "too much, too expensive" water in its early years of operation, subsidies (via property taxes) and expansion of MWD's service area brought reduced prices and expanded demand. (Holding supply constant, that meant that the quantity demanded rose to meet supplies.) On subsidies and sprawl, note that it was not until 1954 that Met's revenue from selling water exceed the cost of delivering it; it was not until 1973 that revenue from sales exceeded revenue from taxes. Since about 80 percent of Met's costs are fixed, revenue needs to cover way more than operating expenses if it is going to pay for all costs.
In 1955, the aqueduct was recognized by the
American Society of Civil EngineersThe American Society of Civil Engineers is a professional body founded in 1852 to represent members of the civil engineering profession worldwide. It is the oldest national engineering society in the United States. ASCE's vision is to have engineers positioned as global leaders who strive toward...
(ASCE) as one of the "Seven Engineering Wonders of American Engineering".
External links