September 28, 2014

Colorado River supply concerns mounting

Lake Mead levels stand at an all-time low

By Dale Rodebaugh
Durango Herald

The water in Navajo Reservoir could play a role in meeting Colorado River Compact obligations in the event of continued drought, said Bruce Whitehead, director of the Southwestern Water Conservation District.

Release of water to Lake Powell from Navajo Reservoir, Flaming Gorge Reservoir on the Green River in Utah and Blue Mesa Reservoir on the Gunnison River is one of three measures his district and the Colorado River District want implemented if water storage in the network that supplies seven Western states approaches crisis level, Whitehead said.

The other measures call for increasing the amount of water available and, lastly, reducing use.

“We’re not in crisis now,” Whitehead said. “The 2013-2014 water year has been almost normal as far as the amount of water in Lake Powell.

“But the reality is that in spite of some good water years, we’re in a 15-year drought,” Whitehead said. “We need a plan to meet a crisis if the same conditions continue.”

The three measures to meet a critical water shortage came out of a recent meeting of Southwestern and the Colorado River District, which between them cover the Western Slope.

The recommendations went to the Upper Colorado River Commission, which regulates water matters in Colorado, Wyoming, Utah and New Mexico, the Upper Basin states that supply Arizona, Nevada and California, the Lower Basin states.

The water from the Colorado River and its tributaries is stored in Lake Powell at Page, Arizona. Lake Powell replenishes Lake Mead located 25 miles from downtown Las Vegas as Lower Basin states use water.

Lake Powell has a capacity of 24.3 million acre-feet, Lake Mead, 28.9 million acre-feet. An acre-foot of water would cover a football field to depth of 1 foot.

This year, Lake Powell has released 7.5 million acre-feet of water to Lake Mead. But the downstream reservoir has supplied more than that amount to Lower Basin states.

Lake Mead currently stands at an all-time low of less than 40 percent of capacity and Lake Powell at around 50 percent of capacity, Whitehead said.

According to agreements, Lake Powell is scheduled to send 8.23 million to 9 million acre-feet to Lake Mead next year.

The concern about Lake Powell is that if water drops below the level needed to generate electricity, federal agencies would lose $120 million a year in power sales.

The revenue from power sales funds among other things environmental programs such as protecting fish species in the San Juan River, Whitehead said.

If the water level in Lake Powell allows generation of power, there should be enough water to satisfy the 1922 Colorado River Compact, Whitehead said.

Again, Whitehead said, Lake Powell and Lake Mead aren’t at critical levels. But the Upper Colorado River Commission and counterparts in Lower Basin states are looking at what-if situations.

Thus, the recommendations from his district and the Colorado River District, Whitehead said.

Measures to increase the amount of water available through cloud seeding, removal of water-hungry nonnative vegetation such tamarisk and Russian olive and evaporation-containment methods are a first step, Whitehead said.

A second early step, Whitehead said, would be the release to Lake Powell of water from Navajo, Blue Mesa and Flaming Gorge reservoirs which, respectively, have acre-feet capacities of 1.7 million, 829,500 and 3.79 million.

The contributions of Navajo and Blue Mesa could be less than optimal because of contractual obligations, Whitehead said. Blue Mesa also generates electricity.

If the first two steps aren’t enough, water users would be affected directly, Whitehead said. The consumption of cities and agricultural users would be reduced. Fallowing of fields also could be required.

The two commissions said if water for agriculture is reduced, the loss must be shared by Colorado River water users on the Front Range.

Front Range users receive 500,000 to 600,000 acre-feet of water a year from Colorado River transmountain diversions, Whitehead said.

Another transmountain diversion sends 90,000 to 100,000 acre-feet a year to the San Juan/Chama Project from the Blanco and Navajo rivers, Whitehead said. Users in Santa Fe and Albuquerque benefit.

A contingency plan may never have to be implemented, but there’s no harm in having it on the shelf just in case, Whitehead said.