Water scarcity worries Arizona as reservoirs hit record lows

Colorado River water levels threaten Arizona state drinking water supply and power generation.

State officials have sounded an alarm on water scarcity as Colorado River reservoirs continue to be depleted. Federal projections show Lake Mead and Lake Powell, the two largest reservoirs in the U.S., will reach a water shortage level ‘likely to trigger larger water cuts in 2023 for Arizona and Nevada’ as well as Mexico. Tom Buschatzke, director of the Arizona Department of Water Resources commented, “The gravity of the immediate situation is serious. We expect further significant actions to reduce water use will be required.”

Arizona state and federal officials met 6 May 2022 in Phoenix soon after the U.S. Bureau of Reclamation announced plans for this year to reduce the amount of water released from Lake Powell to reduce the risk of the reservoir water level falling too low at Glen Canyon Dam. In 2021 the Glen Canyon Dam generated sufficient hydroelectricity to meet the needs of more than 300,000 homes. If reservoir levels plummet too low, the loss of hydropower generating capacity is anticipated.

Buschatzke said the latest water level projections show that reduced water release from Lake Powell to Lake Mead will result in a “roughly 22-foot drop in Lake Mead’s level.”

Mead is already at 30% of capacity, the lowest level since it was filled in the mid- to late 1930s, when the Hoover Dam was completed. Water management officials are concerned that Lake Mead’s reservoir level may drop to 895 feet, reaching ‘dead pool’ from the current elevation of 1,054 feet. At dead pool, water will not pass through Hoover Dam – critical infrastructure that distributes irrigation water and produces renewable energy. Its role in flood control seems less relevant as the western region continues to face a 22-year drought.

Despite collective efforts by California, Arizona, and Nevada in addition to Mexico to withdraw less water from the Colorado River, reservoir water levels continue to decline. Higher ambient air temperatures are drying out soil moisture and evaporating water.

“We’re getting way less runoff than we’re getting precipitation, a disturbing trend and a challenge for us managing the river moving forward,” remarked Buschatzke. He advised Arizonans to prepare for additional cuts in 2023 and even larger water budget cuts in 2024.

This year the snowpack was a little below average, but inflow from snow meltoff is projected to be 62% of average according to Dan Bunk, Chief of USBR’s Boulder Canyon Operations Office. “We seem to be getting precipitation, but … warmer temperatures and dry soil conditions … all seem to be conspiring, to some extent, against the actual runoff.”

Reclamation monitors snow and other basin conditions since snow acts as a frozen water reservoir which later runs off into drinking source water in its watersheds. Based on this snow monitoring data, the federal agency forecasts water supplies.