When the Lights Go Out in Las Vegas
by John Lawrence
Climate change is reducing the abilities of the west's 2 main reservoirs, Lake Mead and Lake Powell, to provide water and hydropower to 7 western states. The water elevation in these reservoirs has gotten so low that the water intake valve is exposed so they had to drill another one even lower. How low can they go? Reservoirs upstream from lake Mead can release water to elevate Lake Mead, but there are only so many acre-feet available in total because of the mega drought brought on by climate change. The west relies on Colorado river water which comes from the snowpack in the Sierra Nevada mountains. As earth has warmed, less snow and more rain has fallen in the mountains. This means that there is more flooding and less gradual release of water in the summer months as the snowpack melts. The net result is that there is less water and power available. If the water level gets too low the hydro electric generators must be turned off because there is not enough water pressure to run them.
USA Today reported:
When the water level in a dam falls so low that an intake valve becomes exposed, you know the lake is in trouble. But when that happened this week at Lake Mead, it didn't surprise experts or state and federal officials.
They have known that Lake Mead, the nation's largest manmade reservoir and home to Hoover Dam, is hitting historic low water levels, threatening the water supply for as many as 25 million people in the western U.S.
Water levels at Lake Mead, located in Arizona and Nevada, have dropped to elevation 1,055 feet, the lowest since 1937, a year after Hoover Dam became operational and created the reservoir. In comparison, Lake Mead was at elevation 1,080 feet this time a year ago – a year in which federal officials declared a water shortage for southwestern U.S. areas served by Lake Mead.
To add insult to injury, the less that renewable and non-polluting hydropower is available, the more polluting natural gas has to be burned to provide power. Hoover dam is home to one of the largest hydropower plants in the country, supplying power to around 1.3 million people in Nevada, Arizona and California, including tribal communities in the region. Hoover Dam's hydropower efficiency has dropped about 25% due to the historically low levels. As of March, 2022, the water level in Lake Mead was 1061.49 feet.The hydropower plant will continue generating power until Lake Mead's water level hits 950 feet. The Bureau of Reclamation says Lake Mead has an increased likelihood of hitting 1,025 and 1,000 feet by 2025, estimating the chances at 58% and 21%. So it's only a matter of a few years before both water and power are shut off to millions of people in the west since climate change is only getting worse. Already Los Angeles has imposed water restrictions. It gets 15% of its water from Lake Mead. San Diego is more fortunate. More than 43 percent of San Diego's power comes from renewable sources like solar and wind – and a majority of the rest is natural gas.
To reduce its dependence on Colorado river water San Diego built a seawater desalination plant, the largest in the United States and now the envy of desperate communities up the coast, in spite of environmental concerns. Since 2015, millions of gallons of seawater have flowed into the $1 billion facility in Carlsbad each day, where it is filtered into something that tastes like it came from an Evian bottle, not the Pacific Ocean. San Diego also made a deal with Imperial County farmers to take some of their water which they reclaimed by lining an aqueduct to save water seepage into the earth. Eventually farmers all over the state will lose their water allotments in order to continue to send water to households. That means that California crops which feed much of the country and indeed the world will become less available and prices will rise.
The basic problem is that most southern California water is shipped in from northern California. Southern California itself is mainly a desert with few natural sources of water. The same is true for the other western states that rely of Colorado river water. The large reservoirs will probably dry up before 2030. That means that coastal cities like LA will have to build more expensive desalination plants. Inland cities will be out of luck unless they can build more dams to harness water runoff instead of snowpack runoff. Agriculture will largely become a thing of the past in these areas. This phenomenon is happening all over the world in particular in those areas which rely on Himalayan and Andes glaciers. India, China and other Asian and South American countries are also being affected. Renewable energy can solve much of the power generation, but water sources will be increasingly challenged especially as the population increases will result in demand for more not less water.
