Colorado River Cuts Will Affect California and Two Other States

Federal reductions in Colorado River deliveries will soon begin in California, Arizona and Nevada. The river serves over 40 million residents in seven states, including Los Angeles and San Diego, while also irrigating five million acres of agricultural land. For Simi Valley residents, the immediate regional significance is California’s inclusion in the reductions and the river’s role in supplying major Southern California cities.

Lake Mead and Lake Powell, the nation’s two biggest reservoirs, now hold only 25 percent of their total combined capacity. Lake Mead has never been lower; its waterline stood 175 feet higher in 2000. The Southern Nevada Water Authority’s original municipal intake, built in 1970, is now above the water and unusable. An intake constructed nearly 200 feet deeper, together with a large pumping station, cost the authority more than a billion dollars.

The decline follows decades of heavy use and a 26-year-long megadrought. Since 2000, Colorado River flows have fallen 20 percent as limited precipitation and extreme heat reduced moisture in soil and waterways. Another small drop at Lake Mead could cut Hoover Dam’s hydropower production by 70 percent. Water managers are already funding alternatives: Phoenix plans three recycling facilities, and its first advanced purification plant is expected to open next year and provide nearly seven million gallons daily. Disputes over the federal reductions could ultimately reach the Supreme Court.