Agricultural Irrigation & Drainage
The Valley’s Success Is in Its Agricultural RootsThe Coachella Valley’s farmland is among the largest crop-growing regions in the state, renowned for its dates, citrus, grapes, and bell peppers. More than 2/3 of local farmland is irrigated in part with Colorado River water delivered via the Coachella Canal, a branch of the All-American Canal. Thanks to the Coachella Canal, Coachella Valley Water District delivers 280,000 acre-feet annually of imported water to some of the most productive farms anywhere in the world.
The 123-mile Coachella Canal and its underground water delivery system, managed by CVWD and used to irrigate nearly 60,000 acres of farmland, continues to attract irrigation specialists from throughout the world, more than a half century after it was built.
Watch the Colorado River Special - Huell Howser and Peter Nelson 2003 video on YouTube.
More than 60% of area farms use drip or other micro-irrigation. This reduces water use, allows pesticides and herbicides to be added directly into irrigation lines and contributes to increased crop yields. Area farms are among the most efficient agricultural water users in the state.
Farming in the Coachella Valley is an incredible success story. More than a century ago, farmers came to the Coachella Valley for cheap land, a warm climate that allowed for year-round growing and a seemingly endless abundance of water. Much of that water once flowed freely to the surface because of plentiful artesian wells. During those early years, farming proved to be too successful as agricultural growth led to a dramatic drop in groundwater tables at a time when there were no other available sources of water.
If CVWD had not worked to import Colorado River water to the valley in the early decades of the 20th century, the local aquifer would have been overdrawn to a point where it would have been too costly to operate wells, there would have been no supply of water for agricultural irrigation and farming might have ceased as a viable industry. In fact, the Coachella Canal allowed agriculture to boom for decades and preserved precious groundwater for residential growth.
An Engineering MarvelFor decades after it was built, the Coachella Canal was considered an engineering marvel around the world. Water travels down the canal entirely by gravity flow, thus eliminating all electricity costs normally associated with pumping. This energy savings is passed on to canal customers in the form of lower water rates.
Coachella CanalThe water that flows through the canal travels several hundred miles, beginning at the Colorado River and diverted into the All-American Canal at the Imperial Dam, located 18 miles north of Yuma, Arizona. The water is then diverted again 37 miles downstream into the Coachella Canal, a branch of the All-American Canal.
Construction of the canal began in the 1930s but was interrupted by World War II. Work resumed when the war ended. Construction was completed in 1948. The first water deliveries were made in the 1949.
The 122-mile canal has the capacity to handle a flow of water up to 1,300 cubic feet per second, allowing for nearly 2,600 acre-feet of water to be delivered in a 24-hour period. This equates to the potential delivery of nearly a million acre-feet of water in a year! One acre foot is equivalent to 325,851 gallons of water.
The district’s 500-mile underground delivery system was built in the 1950s. This lateral distribution system delivers water to farmers at the highest point of every 40 acres of eligible land within the district's service area.
Underground Delivery System
Shortly after work on the canal was completed, construction began on an underground tile drainage system designed to carry used agricultural irrigation water away from farmland and to the Salton Sea. Today, this system boasts nearly 2,500 miles of on-farm and district-maintained drains.
Effective Drainage Disperses Harmful Salts
Experts believe many agrarian-based, ancient civilizations perished because they had inadequate drainage for farmland. As a result, a buildup of salt in the soil made it unusable for crops.
CVWD maintains the valley’s drainage system that serves more than 37,000 acres of farmland.
In 2005, CVWD received a state grant to research effective ways to desalinate drainage. In the future the district intends to use up to 11,000 acre-feet of treated drainage annually for outdoor irrigation.
When built, the 37 most northern miles of the Coachella Canal were lined with concrete to ensure more efficient connections to the underground distribution system.
Along the Canal, Every Drop Counts
In 1980, the 49 southern miles of the canal were replaced by a parallel concrete waterway that resulted in a savings of more than 130,000 acre-feet of water each year.
The remaining 36 miles of earthen waterway were replaced with a parallel, concrete canal in 2006. That project was funded by the state and the San Diego County Water Authority as part of the Quantification Settlement Agreement of 2003 (PDF). The net of 26,000 acre-feet of Colorado River water conserved from eliminated seepage is now redirected to meet urban water demand in San Diego County.
Construction in 1969 of Lake Cahuilla gave CVWD greater control over the flow of canal water into the valley. When constructed, the lake was the largest soil-cement lined reservoir in the world. Lake Cahuilla’s storage ability is a valuable surplus in the event of changing irrigation needs. The lake is located between Avenues 56 and 58, west of Jefferson Street in La Quinta. It is 3/4 of a mile long, up to half that in width, 10 feet deep, and it holds about 1,300 acre-feet of water. Riverside County oversees the lake's recreational uses and stocks it with fish. Today, while fishing is prohibited along the canal, Lake Cahuilla is a popular spot for fishing, camping and day-use recreation.
Diversified Water NeedsInitially, water delivered from the canal was used exclusively by agriculture. As residential growth moved into the eastern valley other water users, primarily golf courses and homeowner associations, began using Colorado River water for large landscape irrigation. The use of canal water for non-potable purposes helps conserve the valley's groundwater supply for domestic use.
Today, water imported via the Coachella Canal is also used at 2 groundwater replenishment facilities that benefit the eastern Coachella Valley’s aquifer. In the future, the canal may provide a potential source of water for CVWD to treat to drinking standards and deliver to urban customers.