Hedge our water bets — @BigPivots – Coyote Gulch

Las Vegas Lake Mead admission diagram, courtesy of SNWA.

Click the link to read the article on the Big Pivots (Allen Best) website:

Las Vegas in 2007 bet on lowering reservoir levels in the Colorado River. The bet now pays off. Municipal water suppliers in Colorado have started to tighten the tap for landscaping. This decision is also wise – but late?

The receding waters of Lake Mead exposed sunken boats, corpses and more. But the wisdom of a bet placed in 2005 by Las Vegas has also been unveiled.

The Southern Nevada Water Authority gets 90% of its water for a population of 2.3 million from Lake Mead. It had two intake pipes, one upper and one lower in the tank. Reservoir levels have dropped precipitously since 2002, when the Colorado River provided just 3.8 million acre-feet of flow. The 1922 pact between Colorado and the other seven basin states assumes more than 20 million annual flows.

Las Vegas dug a third tunnel, this one coming from the bottom of the reservoir. The foresight of this investment and other investments totaling $1.3 billion was revealed in April when reservoir levels fell below what was needed for the highest intake pipe. Dependent on the Colorado River, Las Vegas had wisely hedged its bet.

The facade of the Steamboat Springs municipal building has been designed to use less water. Top photo, Lake Mead floats boats under the now famous Bathtub Ring in December 2021. Photos/+Allen Best

Drought combined with aridification produced by warming temperatures have upset the char in the Colorado River Basin. Apples are rolling everywhere. The simple, visual way to tell this story is with tub rings widening into the giant reservoirs of the Colorado River. Mead and Powell are 73% and 74% empty, respectively.

But the bigger story will be about demand reduction in Colorado and the other six basin states. It falls to California, Arizona and Nevada, especially California, which for years of drought has gulped too generously given emerging climate realities.

Colorado and other upper basin states lived within their compact means. But here, too, changes are afoot, because the water just isn’t there. Farms and ranches, which still consume more than 85% of the water in Colorado, will have to be history. It will be the same for towns and cities still growing.

The changes can be seen most obviously in those places on the outskirts, including the fast-growing suburbs of Aurora and Castle Rock. They are redefining acceptable landscapes in the semi-arid West. Sprawling lawns resembling those of the rain-soaked Eastern states are disappearing.

In Aurora, Colorado’s third-largest city with nearly 400,000 residents, the city council last week approved regulations severely limiting lawns on golf courses and new homes. Residential lots will be limited to 45% or 500 square feet of the yard, whichever is less, for grass. Within this boundary are other boundaries. More Kentucky bluegrass. Other varieties consume less water

The elected officials of Castle Rock, a city of 80,000 inhabitants which expects to fully fill its britches to 142,000 inhabitants, are reviewing similar regulations in early September. “Coloradoscape” is what Castle Rock calls its recommended landscapes. For homes, 500 square feet is tiny, smaller than some bedrooms. For new construction sites, this will be the max. Mark Marlow, director of Castle Rock Water, said town leaders began meeting with stakeholders, including homebuilders, in November.

Marina at Lake Mead. Photo credit: Allen Best/Big Pivots


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