Lake Mead Water Level Dropping

Category: Hoover Dam | 21/04/2009 - 05:49:39

Lake Mead

Created by water trapped by the Hoover Dam, Lake Mead is the United States’ largest man-made reservoir - 640 square kilometres in area and up to 500 feet deep in parts. Aqueducts connect Lake Mead’s water to millions of people living both in Nevada and California.

Lake Mead - Could it Dry Up?

Recent scientific research, highlights how Lake Mead could dry up completely before long, as a result of climate change, as well as other factors like water management and the needs of an ever-increasing population.

The Hoover Dam sits between Nevada and Arizona.  Construction of the Hoover Dam finished in 1936, at which point it stood as the largest electric-power generating site in the world, as well as the largest structure made out of concrete – twin titles that it held onto for nine years.

These days, Hoover Dam – the name of which came from Herbert Hoover, the former US President - is still globally significant in terms of size and power – it being the 35th largest site of its kind in the world.

In terms of power output, the Hoover Dam is capable of producing approximately 4 billion Kilowatt-hours (KW-h) per annum. The water turbine’s highest power output capacity at any one time is 2.08 Gigawatts.

The Hoover Dam is comprised of 17 turbines, 15 of them rated at 178,000 horsepower, one at 100,000 horsepower and one at 86,000 horsepower.

Lake Mead forms part of the Colorado River system, and is itself made up of a number of basins – Boulder Basin, Virgin Basin, Temple Basin and Gregg Basin.

According to a pair of researchers at San Diego’s Scripps Institution of Oceanography, David Pierce and Tim Barnett, the annual rate of water loss from this system is approaching one million acre-feet.

Lake Mead’s water disappearance, the two scientists say, is linked to the following factors:

  • Naturally-occurring evaporation
  • The demand placed on its water supply by the millions of people who draw upon it
  • Climate change as a result of human activity

Even if measures are put in place to halt Lake Mead’s water level drop, the suggestion is that it and other rivers could still become empty in the very near future.

Pierce and Bennett estimate the chance of this happening within just five years at 10 per cent and, within 12 years, 50 per cent.

Lake Mead Water Level Drop

Over the past nine years alone, Lake Mead’s water level has dropped by in excess of 100 feet.

Lake Mead Water Levels

In mid-April 2009, the US Bureau of Reclamation forecast that, within three months (by July 2009), the water level would have come to rest at 1,092 feet – its lowest level for over four decades.  17 feet lower and, at 1,075 feet, it would be at the height at which – under the terms of a 2007 agreement – the lake would be declared officially short of water.

A measurement of its overall capacity taken on April 13th highlighted how Lake Mead was a staggering 54 per cent empty.

Beyond the implications for residents living in the areas which Lake Mead supplies, the water loss has ramifications for the local economy too: a recent estimation suggested that Lake Mead National Recreation Area, along with affiliated marine operators, were losing around $3 million for every ten foot of lake lost.

Marinas and ramps used for launching boats used to be plentiful – now, few remain, and those that are still there have been forced to relocate as a result of the water drop.

Visually, Lake Mead’s water level drop is very apparent, with a white line around its edges indicating the water’s previous height.

This part of the US has suffered from droughts in recent times, meaning that the River Colorado has fed less and less water into the lake.  Natural river fluctuations, however, mean that the exact moment when the last drop of water leaves Lake Mead is impossible to predict.  The same goes for if it will actually dry up at all.

Despite this, the scientific research intimates that total water loss by 2021 is as probable as it is not – a highly alarming forecast.

Barnett’s and Pierce’s forecast formed part of a publication issued in 2008 entitled ‘When will Lake Mead go dry?’ “We were stunned at the magnitude of the problem and how fast it was coming at us”, Barnett said at the time. “Make no mistake, this water problem is not a scientific abstraction, but rather one that will impact each and every one of us that live in the Southwest."

Pierce – commenting on the wider effects of Lake Mead’s water level drop – added: “It's likely to mean real changes to how we live and do business in this region.”

The same message was given at the report’s end, which asserted: “The alternative to reasoned solutions to this coming water crisis is a major societal and economic disruption in the desert southwest; something that will affect each of us living in the region.”