2016-05-20. Unplugging the Colorado River.

posted May 25, 2016, 1:50 PM by Alan Gould
By Abrahm Lustgarten, The New York Times. For GSS Energy Use chapter 4. Excerpt: When Glen Canyon Dam was built in the middle of the last century, giant dam projects promised to elevate the American West above its greatest handicap — a perennial shortage of water. These monolithic wonders of engineering would bring wild rivers to heel, produce cheap, clean power and stockpile water necessary to grow a thriving economy in the desert. ...Climate change is fundamentally altering the environment, making the West hotter and drier. There is less water to store, and few remaining good sites for new dams. Many of the West’s big dams, meanwhile, have proved far less efficient and effective than their champions had hoped. They have altered ecosystems and disrupted fisheries. They have left taxpayers saddled with debt. And in what is perhaps the most egregious failure for a system intended to conserve water, many of the reservoirs created by these dams lose hundreds of billions of gallons of precious water each year to evaporation and, sometimes, to leakage underground. ...it is not just the reservoir’s overuse that is causing it to shrink. More than 160 billion gallons of water evaporate off Lake Powell’s surface every year, enough to lower the reservoir by four inches each month. Another 120 billion gallons are believed to leak out of the bottom of the canyon each year into fissures in the earth — a loss that if tallied up over the life of the dam amounts to more than a year’s flow of the entire Colorado River. ...Glen Canyon is not the only dam to fall out of favor. Other major projects are also being decommissioned or re-evaluated. The Hoover Dam’s Lake Mead, which on Wednesday fell to its lowest level ever, some 145 feet below capacity, also loses hundreds of billions of gallons to evaporation and is now 37 percent full. The lake behind Arizona’s Coolidge Dam, one of the state’s largest reservoirs, is virtually empty. ...Six Western dams were deconstructed in 2015 alone. Just last month California and Oregon agreed to dismantle four more power-generating dams on the Klamath River, having realized that the facilities were crippling native salmon fisheries, which also have enormous economic value....  http://www.nytimes.com/2016/05/22/opinion/unplugging-the-colorado-river.html