Lake Mead Waters Dropping; Hoover Dam Electricity Could Stop

The water levels behind the Hoover Dam are drying up amid a summer drought and are dangerously low to the point of becoming a dead pool, a problem for anyplace that relies on the dam's hydroelectricity.

It had been a shining example of hydroelectric power, a key selling point of green energy. Now, it might become a dud.

The problem is the water flow of millions of gallons of Colorado River water hurtle through the Hoover Dam every day, generating electricity for hundreds of thousands of homes. Stagnant waters would create another stress on California energy shortages.

Nevada and Arizona also get hydroelectricity from the Hoover Dam, which generates 4 billion kilowatt-hours every year, enough to serve 1.3 million people according to the U.S. Bureau of Reclamation (USBR).

"We are [in the] 23rd year of drought here in the Colorado River Basin and Lake Mead has dropped down to 28%," USBR's Patti Aaron told AFP.

"There isn't as much head so there isn't as much pressure pushing the water into the turbines, so there's less efficiency and we aren't able to produce as much power."

Dead pool waters are when levels get so low they do not flow downstream any longer.

Hoover Dam was a feat of American hope and engineering. Construction began in 1931 as the country was withering under the Great Depression. The dam stopped up the Colorado River, creating Lake Mead, the biggest reservoir in the United States.

At its height, the lake surface sits over 1,200 feet (365 meters) above sea level. But after more than two decades of drought it is now less than 1,050 feet — the lowest since the lake was filled, and falling about a foot a week.

If it drops to 950 feet, the intakes for the dam will no longer be under water and the turbines will stop.

"We're working very hard for that not to happen," Aaron said. "It's just not an option to not produce power or not deliver water."

The Colorado River starts in the Rocky Mountains and snakes its way through Colorado, Utah, Arizona, Nevada, California and northern Mexico, where it empties into the Gulf of California.

It is fed chiefly by the huge snowpack that gets dumped at high altitudes, melting slowly throughout the warmer months.

But reduced precipitation and higher temperatures means less snow is falling, and what snow there is, is melting faster.

As a consequence, there is not as much in a river that supplies water to tens of millions of people and countless acres of farmland.

Boaters on Lake Mead, many of whom come from Las Vegas and its surrounding towns, say they are doing their part to protect supplies.

They point to the drought-tolerant landscapes they have installed instead of lawns, and the high percentage of indoor water that is recycled in desert towns.

"But you've got farmers in California growing almonds for export," said Kameron Wells, who lives in nearby Henderson, Nevada.

Householders in southern California have grumbled about the fate of their luscious lawns since being ordered to limit their outdoor watering to one or two days a week at the start of the summer.

But there, like in the desert periphery of Las Vegas, there is plenty of new construction, with huge houses being put up in the resort settlement of Lake Las Vegas.

And from the air, the vibrant green of dozens of golf courses mark an otherwise dust bowl landscape.

Climatologist Steph McAfee of the University of Nevada, Reno, said the U.S. West has always been something of an improbability.

"The average precipitation in Las Vegas is something like four inches (10 centimeters) a year," she told AFP.

"And to make it possible to have cities like Las Vegas and Phoenix and Los Angeles we rely on water that falls in the mountains as snow in parts of the West that are obviously much, much wetter."

The past two decades of drought are not, McAfee said, actually that unusual in climatic terms, according to tree ring reconstructions.

A sunken boat dating back to World War II is the latest object to emerge from a shrinking reservoir that straddles Nevada and Arizona.

The Higgins landing craft that has long been 185 feet below the surface is now nearly halfway out of the water at Lake Mead.

The boat lies less than a mile from Lake Mead Marina and Hemingway Harbor.

It was used to survey the Colorado River decades ago, sold to the marina and then sunk, according to dive tours company Las Vegas Scuba.

Higgins Industries in New Orleans built several thousand landing craft between 1942 and 1945, the Las Vegas Review-Journal reported. Around 1,500 "Higgins boats" were deployed at Normandy on June 6, 1944, known as D-Day.

The boat is just the latest in a series of objects unearthed by declining water levels in Lake Mead, the largest human-made reservoir in the U.S., held back by the Hoover Dam. In May, two sets of human remains were found in the span of a week.

U.S. Bureau of Reclamation Commissioner Camille Touton said last month the agency would take action to protect the system if the seven states in the Colorado River basin do not quickly come up with a way to cut the use of up to 4 million acre-feet of water — more than Arizona and Nevada's share combined.

An acre-foot is about 325,850 gallons. An average household uses one-half to one acre-foot of water a year.

The two states, California and Mexico already have enacted voluntary and mandatory cuts. Water from some reservoirs in the upper basin — Wyoming, New Mexico, Colorado and Utah — has been released to prop up Lake Powell.

Farmers use a majority of the river's supply.

Information from AFP and The Associated Press were used in this report.