LAKE MEAD, ARIZONA — Lake Mead is the massive lake that was created when the Hoover Dam was finished in 1936.
This vital reservoir has now reached the lowest level it has ever been and weather forecasts show that it will probably drop a lot lower.
If this happens, all electricity generation inside the Hoover Dam's wall will shut down, and thousands of farms will turn back to the dust they were before the dam was built.
Here are the details: NBC News reports that water levels in Lake Mead — the largest U.S. reservoir by volume — fell to 36 percent, its lowest level ever, on Thursday 11 June, as the region continues to face the effects of a devastating prolonged drought.
Lake Mead was formed when the Hoover Dam was built in the 1930s.
It provides water for urban, rural and tribal lands across the south-west.
Officials expect levels to get worse through another dry, hot summer.
In normal years, the dam produces enough electricity for 8 million people, but the water shortage will slow energy output.
Every foot of lake-level decline means about six megawatts of lost capacity.
The Hoover Dam's energy capacity has already dropped by 25% and levels will continue to decline through this autumn.
Las Vegas recently became the first city in the U.S. to ban "useless grass" around streets, offices and housing developments, in an effort to conserve water.
The devastating drought has caused the Colorado River system to decline to half its capacity, and the basin has seen historically low inflows over the last 16 years.
The rapid decline has prompted plans for the first ever water-shortage declaration from the federal government.
The declaration, which will probably be issued in August of this year, would affect distribution to states and Mexico.