Vanishing water — The Las Vegas Desert Sun #ColoradoRiver #COwater

Drought affected Lake Mead via the Mountain News
Drought affected Lake Mead via the Mountain News

Here’s an in-depth look at Climate Change and the current affects on water supply in the Colorado River Basin, from The Las Vegas Desert Sun (Story by Ian James / Photos by Richard Lui). Here’s an excerpt:

The biggest reservoir in the United States is dropping 1 foot each week. Lake Mead’s rapidly sinking water level is set to reach an all-time low in July, driven down by a 14-year drought that scientists say is one of the most severe to hit the Colorado River in more than 1,200 years.

The water behind Hoover Dam supplies vast areas of farmland and about 25 million people in three states, and this critical reservoir stands just 40 percent full.

Droughts and even decades-long mega-droughts have long been part of the natural cycle of the Colorado River, but that ebb and flow is now occurring alongside global warming, which scientists say is influencing the weather and putting new pressures on water supplies that are already over-tapped and declining.

In many ways, climate change is starting to compound the problems of a water system in the Southwest that is fundamentally out of balance:

• The Colorado River would naturally flow through its delta to the Sea of Cortez. But so much water is taken from the river that it seldom reaches the sea, and federal officials say water use has begun to surpass the available supply, drawing down the river’s reservoirs.

• Beneath desert cities and towns, in places from Palm Desert to Borrego Springs, groundwater levels have been dropping as more water is pumped from wells than flows back into aquifers.

• Scientists aren’t sure to what degree climate change is influencing the natural cycle of droughts in the West, but they say it’s clear that hotter temperatures worsen droughts, meaning that future dry spells will become more intense, more frequent and longer-lasting. And the current drought is taking an economic toll on agriculture in California’s Central Valley, with UC Davis researchers estimating losses this year at $1.7 billion.

• Already, scientists say hotter temperatures across the West have led to less mountain snowpack and earlier melting of snow in the spring. More of the snow and rain that does fall is evaporating due to warmer temperatures, and that diminishes the flows of water into the Colorado River that sustain cities and farms across the Southwest.

More Colorado River Basin coverage here and here.

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