Sunday, May 17, 2015

"Cool Water"

One of the classic Country-Western songs was "Cool Water," about a cowpoke looking forward to ending the day's ride at a peaceful watering hole. The following video features Marty Robbins singing:


In most of the western United States, water is scarce. Because of this, many western states abrogated the common law right to riparian water in favor of water rights based on seniority of who first developed or used a water source. Consequently, it is possible to have a well, spring, or stream on your property without having any legal right to use the water. As you can guess, the shortage of water led to violence in the Old West, as well as to large irrigation and reclamation projects to increase the efficiency of water use, including the construction of large dams and reservoirs to control flooding, store water, and/or produce electricity. One of the largest of these projects was the Hoover Dam, which formed Lake Mead on the Colorado River--one of the most important sources of water for Nevada, Arizona, and Southern California. But the current drought and over allocation of the river's resources had led to steadily declining levels of water in Lake Mead over the past decade.

Voice of America has a special report on the current condition of Lake Mead. It indicates:

Lake Mead anchors the lower half of the river basin, a system that provides water to nearly 40 million people in seven U.S. states. Cities from San Diego to Denver drink from the Colorado. The river irrigates m
Lake Mead anchors the lower half of the river basin, a system that provides water to nearly 40 million people in seven U.S. states. Cities from San Diego to Denver drink from the Colorado. The river irrigates more than 5 million acres of farmland, including California’s Imperial Valley and Arizona’s Yuma County, two areas that supply the nation with most of its vegetables through the winter season. Both would be barren without its waters.
* * *
Arizona State University researchers calculated that the river supports 16 million jobs, generates $870 billion in income for workers and contributes $1.4 trillion to the region’s economy.
But after 14 years of drought, the system is closer to failure than ever.
This summer, Lake Mead hit a re* * *cord low. At 1,080 feet above sea level, it was less than 40 percent full and just 5 feet from the point at which water authorities must cut deliveries downstream for the first time ever. Winter rains have raised the lake a few feet. But forecasts are not looking good. A cut is expected as soon as 2016. Farmers in central Arizona would take the first hit.
A 30-foot drop, to 1,050 feet, threatens the equipment that generates enough hydroelectricity to meet the needs of 1.3 million people in Southern California and beyond.
At 1,000 feet, the lower water intake for the city of Las Vegas sucks air. The city is building a “third straw” to draw water from the bottom of the lake, at a cost of $817 million.
The reservoir hits “deadpool” at 895 feet. Below that point, water no longer flows out of the lake, leaving users in California, Nevada and Arizona dry.
* * *
The lake sits in a V-shaped basin, narrower at the bottom than the top. That means the lower the water level gets, the faster it drops.
The current drought is already the worst in a century of recorded history. But tree-ring records and other proxy climate data going back more than a millennium show it could still get much worse.
“That region has experienced extended droughts, much longer than the current drought,” said Debra Knopman, principal researcher at the RAND Corp. “These droughts can persist for decades, in fact.”
Even when the drought does end, the region’s water troubles will not. They started even before Hoover Dam was built.
When a 1922 law divided the waters of the Colorado River among the seven basin states, hydrologists had just a few short decades of data on how much flowed in the river.
“Lo and behold, it turns out that that was a period of high flow,” Knopman said.
The river has rarely delivered that much water since. As a result, every drop of its water is spoken for, and then some. And cities that drink from the river continue to grow.
“All the users on the system live on the razor’s edge,” said Kathryn Sorensen, water services director for the city of Phoenix. “We use everything that’s available to us every year. And what that means is, we’re not leaving water behind to prop up levels in Lake Mead to provide for resilience in drought, megadrought [or] climate change.”
And that’s a problem, she said. Most models show the region getting warmer and drier through this century, and droughts will get longer and more severe.
One 2008 study gave 50-50 odds that Lake Mead would hit deadpool by 2021.
* * *
More than 5 million acres of farmland, including California’s Imperial Valley and Arizona’s Yuma County, two areas that supply the nation with most of its vegetables through the winter season. Both would be barren without its waters.

* * *

Arizona State University researchers calculated that the river supports 16 million jobs, generates $870 billion in income for workers and contributes $1.4 trillion to the region’s economy.
 
But after 14 years of drought, the system is closer to failure than ever. 
This summer, Lake Mead hit a record low. At 1,080 feet above sea level, it was less than 40 percent full and just 5 feet from the point at which water authorities must cut deliveries downstream for the first time ever. Winter rains have raised the lake a few feet. But forecasts are not looking good. A cut is expected as soon as 2016. Farmers in central Arizona would take the first hit. 
A 30-foot drop, to 1,050 feet, threatens the equipment that generates enough hydroelectricity to meet the needs of 1.3 million people in Southern California and beyond. 
At 1,000 feet, the lower water intake for the city of Las Vegas sucks air. The city is building a “third straw” to draw water from the bottom of the lake, at a cost of $817 million. 
The reservoir hits “deadpool” at 895 feet. Below that point, water no longer flows out of the lake, leaving users in California, Nevada and Arizona dry.

* * *
The lake sits in a V-shaped basin, narrower at the bottom than the top. That means the lower the water level gets, the faster it drops.
 
The current drought is already the worst in a century of recorded history. But tree-ring records and other proxy climate data going back more than a millennium show it could still get much worse. 
“That region has experienced extended droughts, much longer than the current drought,” said Debra Knopman, principal researcher at the RAND Corp. “These droughts can persist for decades, in fact.” 
Even when the drought does end, the region’s water troubles will not. They started even before Hoover Dam was built. 
When a 1922 law divided the waters of the Colorado River among the seven basin states, hydrologists had just a few short decades of data on how much flowed in the river. 
“Lo and behold, it turns out that that was a period of high flow,” Knopman said. 
The river has rarely delivered that much water since. As a result, every drop of its water is spoken for, and then some. And cities that drink from the river continue to grow. 
“All the users on the system live on the razor’s edge,” said Kathryn Sorensen, water services director for the city of Phoenix. “We use everything that’s available to us every year. And what that means is, we’re not leaving water behind to prop up levels in Lake Mead to provide for resilience in drought, megadrought [or] climate change.” 
And that’s a problem, she said. Most models show the region getting warmer and drier through this century, and droughts will get longer and more severe. One 2008 study gave 50-50 odds that Lake Mead would hit deadpool by 2021.
Read the whole thing.

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