California's Water: What's New on the Colorado River?

The Colorado River has long been an important source of water for California, providing precious supplies for more than 600,000 acres of farmland and much of urban Southern California. Local water agencies that rely on the Colorado have committed billions of dollars to develop new programs to stretch water supplies and help the state reduce its historic over-use of the river.

This segment of “California’s Water” looks at the canals and aqueducts that bring Colorado River water to Southern California and the many efforts under way to use water as efficiently as possible. Viewers will get a close look at projects to line an earthen canal with concrete, and learn about a 50-year program to improve habitat and protect species along the Colorado River. Background on the Issue

The Colorado River was first tapped for human use some 1,500 years ago. Since then, it has been allocated and re-allocated for a variety uses among seven Western states. Colorado River water has been the lifeblood for cities such as Denver, Las Vegas, Phoenix, San Diego and Los Angeles, as well as more than 3.5 million acres of farmland.

Increasing demands on the river and several years of severe drought have ignited interest in finding new ways to manage the Colorado and maximize its supplies. California, which historically used more water than its 4.4 million acre-feet entitlement, came under extreme pressure in the late 1990s to reduce its reliance on the Colorado.

In October 2003, the state and federal governments and four local agencies that rely on the Colorado River (Coachella Valley Water District, Imperial Irrigation District, Metropolitan Water District of Southern California and San Diego County Water Authority) finalized agreements to execute a landmark water-sharing accord known as the Quantification Settlement Agreement (QSA).

The agreement provides a transition period for California to implement water transfers and supply programs that will reduce its over-dependence on the river. The QSA also commits the state to restoring the environmentally sensitive Salton Sea and provides full mitigation for implementation of the water supply programs.

Current Efforts

A key element of the agreement is the historic transfer of water from Imperial Irrigation District to the San Diego County Water Authority – the largest transfer of water from agricultural use to urban use in U.S. history. The first 10,000 acre-feet of water was transferred in San Diego in late 2003 as part of the agreement, which calls for deliveries to eventually reach 200,000 acre-feet per year by 2022.

Lining of the Coachella and All-American canals to reduce seepage losses is another key program. Constructing concrete-lined canals alongside what are now earthen canals will result in a total savings of 67,000 acre-feet on the All-American Canal and 26,000 acre-feet on the Coachella Canal, for a total savings of 93,700 acre-feet per year. In exchange for helping to fund the construction, San Diego County Water Authority will receive some 77,000 acre-feet of water annually.

Another key effort is the Lower Colorado River Multi-Species Conservation Program, a habitat-based conservation program aimed at providing for the conservation of over twenty-seven species, including six that are currently listed as threatened or endangered under the federal Endangered Species Act. Through an agreement with the California Department of Fish and Game, it also covers eleven species listed as threatened or endangered under the California ESA.

Specific measures include creation of 8,132 acres of habitat, the establishment of mesquite woodlands and cottonwood-willow riparian zones for birds and animals, and the formation of marsh and backwater areas for certain birds and fish. A fish rearing and stocking program also are planned to help increase populations of two endangered fish species.

The $626 million program will be funded by Arizona, California and Nevada.