Lake Mead sinks to record low

• Lake Mead falls below level that would trigger water-supply shortage if it doesn%27t recover by January
• Water managers expect the lake%27s elevation level to rebound enough to ward off a 2016 shortage
• Drought or no drought%2C the Colorado River is over-allocated%2C experts say

Water levels in Lake Mead dropped to a historic low Tuesday, falling below the point that would trigger a shortage if projections fail to show the massive reservoir will recover by January.

Water managers expect the lake's elevation level to rebound enough to ward off a 2016 shortage thanks to a wetter-than-expected spring. But in the long run, as a Bureau of Reclamation spokeswoman said, "we still need a lot more water."

The reservoir stores water for parts of Arizona, other Western states and Mexico, all of which haveendured a 15-year drought with no end in sight.

The U.S. Bureau of Reclamation would announce a 2016 shortage this August if it projects Lake Mead will be at 1,075 feet or lower at the beginning of next year. Assessments are updated in the middle of every month. This month's report forecasts an improved outlook.

The bureau reported Mead's elevation at 1,074.98 feet Tuesday night. But the elevation climbed slightly above 1,075 feet at 2 a.m. and continued throughout Wednesday. Elevation measures are updated every hour. The current level is the lowest since 1937, two years after the lake began filling, and 150 below the highest level of 1,225 feet in 1983.

Tuesday's historic low signals the reality that Colorado River water users consume more than the river provides, said Drew Beckwith, water-policy manager with Western Resource Advocates, a non-profit environmental law and policy organization.

"This is the check-engine light," Beckwith said. "It really does (make critical) the fact that we have to start changing."

Drought or no drought, the river is overallocated, Beckwith said. He said lower-basin states take more than the river system can sustain.

The upper basin hasn't used its full allocation for years, which has kept the problem at bay because the excess is sent to Lake Mead. But, he said, that setup won't last.

The drought, he said, has just hastened that reality.

Western states are working together to start chipping away at the problem.

Major river users agreed last year to leave hundreds of thousands of acre-feet of water in Lake Mead by 2017 that they would otherwise take. The Central Arizona Project's share is 345,000 acre-feet, or the equivalent of more than 170,000 Olympic-sized swimming pools.

Arizona's water-saving strategies include offering incentives to farmers in Yuma to leave some citrus fields fallow and to farmers in central Arizona to cut back on their water consumption.

Phoenix is also tapping into banked water behind the Roosevelt Dam to offset some of its usual consumption directly from the Colorado River.

Arizona has banked water and enacted regulations to protect residents in major metro areas from draconian cuts if a 2016 or 2017 shortage is declared, but agriculture would take a 50 percent cut from the Central Arizona Project, which brings Colorado River water to the state.

At stake is not only the Southwest's water supply, but the health of ecosystems surrounding the river and economies that depend on the Colorado River. The river attracts 5.36 million adults per year for recreation, supports a quarter million jobs and generates $26 billion in economic impact, according to a 2012 survey for Protect the Flows, an organization that seeks to protect the river.

Many municipalities in desert cities have already made major cutbacks. Las Vegas residents, for example, use 30 percent less water per capita than they did 10 years ago. Phoenix residents have cut back by 27 percent in 20 years.