Thursday, April 08, 2021

America's Mega-Drought

  Almost two-thirds of the contiguous U.S. is beset by abnormally dry conditions. Warm temperatures forecast for the next several months could make it the worst spring drought in almost a decade, affecting roughly 74 million people across the U.S., the National Oceanic and Atmospheric Administration said.

“Climate models project that the American Southwest is very likely to experience more frequent and more severe droughts,” said William Anderegg, a University of Utah biologist and climate scientist. And drought-breaking rainfall will become less frequent.

The Colorado River provides water to more than 40 million people across seven southwestern states, 29 tribal nations and Mexico - and a lot of major cities in those states are heavily dependent on that water. In Las Vegas, 90% of its water supply comes from the river. In Phoenix and Denver it's 50% and in Los Angeles it's 25%.According to a 1922 agreement, each of these seven states have a legal right to a certain amount of the river's water. But this compact was made under the assumption that there was more water than there actually was.

According to the US Drought Monitor, 90 per cent of California is already experiencing drought conditions, and the rest of the American west has been suffering from a "megadrought" since 1999.

"On paper we've allocated 30% more water than what's in the river today," says Eric Kuhn, the former General Manager of the Colorado River District. "And the science suggests that we got a situation where climate change has impacted it even more. The river is probably a third smaller than what was anticipated when the contract was negotiated."

Scientists have been predicting for years that the Colorado River would continue to deplete due to global warming and increased water demands, but according to new studies it's looking worse than they thought.

With a two-decade drought in the southwestern US and record-low snowfalls Expected snow accumulation in the Sierra Nevada and Cascade mountains was 40 per cent below average levels. When the mountain snows melt, they replenish the Colorado River, which supplies much of Southern California with its water. Recent reports show that the river's water flows were down 20% in 2000 and by 2050 that number is estimated to more than double, "Things seem to be happening even faster than the models or scientists were warning just a few years ago," says Brad Udall, a water and climate scientist at Colorado State University. "If you're not worried about all this, you're not paying attention."

It's a problem we can't engineer our way out of any longer, Udall says.

"We have massive dams on the Colorado River already. A bigger bank account with less income doesn't do you a whole lot of good," he warns.

Many agree there is only one solution - use less water.

"Despite the complexities of how we reach the solutions, the problem is really quite simple. It's a mass balance equation. We have too many demands and not enough water," says Lochhead, CEO of Denver Water, Colorado's largest water utility. "And so at the end of the day, demands overall will need to be reduced and managed in order to keep the bank account solvent."


California is facing another drought after a lack of rainfall in March failed to replenish the state's sources of waterThe state is still recovering after a bought of drought conditions between 2012 and 2017, and may be facing down another season of extremely dry weather.

Various tribes have legal rights to 20% of the river's water, yet don't have equal access. One-third of the 350,000 residents on the Navajo Indian Reservation don't have running water. When the 1922 agreement was signed, not a single tribe had a seat at the table.


 Daryl Vigil, co-director of Water and Tribes in the Colorado River Basin, calls this "the institutional theft of tribal water".


"Somebody is using tribal water for free and you know once again tribes are not able to utilise that on their own reservations. And what is the impact of those things?" he asks. "Tribes and tribal sovereigns are still 19 times more likely not to have indoor plumbing, I mean in 2021."


70% of the Colorado River's flow is consumed by agriculture. But as the river dries, eventually a lot of it will have to leave these communities to sustain cities and suburbs, meaning less water for farmers and ranchers.


In addition to hardships for farms and residents of the state, dry drought conditions also result in more destructive wildfires. Higher temperatures and lower moisture rates brought on by drought result in drier flora, which provides fires with greater fuel to burn. San Jose State University's Fire Weather Research Laboratory issued a warning on Monday saying the outlook for this year's wildfire season was "grim," citing the worsening drought conditions.

The water fight over the shrinking Colorado River - BBC News


California facing another drought and worse wildfires after unseasonably dry wet season, officials warn (msn.com)

1 comment:

ajohnstone said...

California and the drought

https://www.theguardian.com/us-news/2021/apr/06/california-is-on-the-brink-of-drought-again-is-it-ready