A second record-setting heat wave and drought conditions in the Western US are combining to cause severe disruptions to human and farm life. Dozens of wildfires are imperiling homes from Arizona to Wyoming. Drought conditions also are pushing important rivers and lakes needed for 🍊water power to historic lows.
60 wildfires are burning. That’s putting pressure on power grids and forcing evacuations of thousands of people in California, Nevada, and Oregon. Wildfires have been growing more frequent and intense in recent years thanks to broader climate trends. Weather in the region is getting hotter and drier, which turbocharges fires. This year has seen more large wildfires through June than any year since 2011.
The West is also experiencing a megadrought. That’s worsening the drought-like conditions that have existed for years along the Colorado River. It is a vital source of water for seven US states and parts of Mexico.
The Colorado is delivering so little water to Nevada’s Lake Mead and Arizona’s Lake Powell that they have neared or reached record lows. Both reservoirs are falling toward “dead pool” status. That occurs when water levels are so low they can’t spin massive hydroelectric power generators buried in the major dams on the lakes. Without that power and water, large swaths of Arizona farmland aren’t growing crops.
The loss of water surely will prompt water conservation efforts, and likely water restrictions, next year, experts said. Conservation groups believe Arizona will lose more than 500,000 acre-feet of water usually delivered by the Colorado River in 2022.
🍊 Extra Juice: Water, The Hoover Dam, and The West
What is the Hoover Dam?
The Hoover Dam was built in the first half of the 20th century to provide water and hydroelectric power to the Southwestern US. Completed in 1935, the dam is situated at the Nevada-Arizona border. It diverts water from the normally raging Colorado River to large reservoirs like Lake Mead. That stored water, in turn, is used to irrigate 2 million acres of land and provide hydroelectric power to the Western US.
Built mostly during the Great Depression, the Hoover Dam was the largest of its kind and a source of national pride at its opening. The dam was designated a National Historic Landmark in 1985 and became one of America’s Seven Modern Civil Engineering Wonders in 1994. It still is considered a marvel of human achievement. It receives 7 million visitors annually, while Lake Mead, the world’s largest reservoir, attracts another 10 million as a popular recreation area.
Why was the Hoover Dam built?
It was constructed for various purposes. First, it was built to control flooding of the Colorado River as it winds its way through the southwest on its way to the Gulf of California. Second, as the Southwest was populated with more people, the need for water and a power source grew ever greater.
How big is the Hoover Dam?
It is nothing short of massive. The dam is 726 feet tall and 1,244 feet long, or almost a quarter of a mile. At its base, the dam is a whopping 660 feet thick. That’s longer than two football fields stretched end to end. At its top, Hoover Dam is 45 feet thick. That may seem thin compared to its massive base, but it’s still nearly as wide as a four-lane highway.
How much water does it supply and how much power does it generate?
The dam is capable of irrigating 2 million acres, while its 17 turbines generate enough electricity to power 1.3 million homes.
How important is the Hoover Dam to the Western US?
It is a vital resource for water and hydroelectric power. It helps to irrigate the parched Southwest landscape so that farms can thrive. Its construction fueled the development of major cities such as Los Angeles, Las Vegas, and Phoenix.
What is happening now with Lake Mead and water supply in the West
Since 2000, the Colorado River’s flow has dropped by 20% compared to the previous century’s average. This year is the second driest on record, cutting down the flow into Lake Mead to just a quarter of what is normal. Only 1.8% of the West is not experiencing some level of drought, with California, Arizona, and New Mexico all experiencing their lowest rainfalls on record over the previous 12 months. That has pushed Lake Mead and another major man-made reservoir, Lake Powell, created by the Glen Canyon Dam, into potential “dead pool” status. The water level in Lake Mead has plunged about 130 feet over the past 20 years.
This has led to a first-tier of federally mandated cuts in water allocation next year. If water levels continue falling, as scientists expect, a second-tier round of cuts could be instituted. These cuts force water restrictions on millions of people throughout the Southwest and West.
Whose water is cut first and how is that determined?
Preexisting agreements among seven states determine how water from the Colorado River is distributed. Those states are California, Utah, Arizona, Colorado, Wyoming, New Mexico, and Nevada. If second-tier cuts are made next year, per those agreements, Arizona would lose nearly a fifth of the water it receives from the Colorado River. Nevada’s reduction, conversely, would be fairly small because its allotment is tied to a period of time when Nevada was sparsely populated.
What happens if people don’t conserve water this year and next year?
Water is a necessary resource, so humans must adjust when supply starts running short. Right now, “things look pretty grim,” Kathryn Sorensen, a water policy expert at Arizona State University, told the Guardian newspaper. “Humans have always been good at moving water around but right now everyone will need to do what it takes to prevent the system from crashing.”