The developing world already knows firsthand that global warming caused by greenhouse gases that humanity emits implies changes in precipitation patterns that increase the probability of droughts. In fact, the lack of rain combined with low adaptive capacity and poorly developed water infrastructure is the reason for real water crises in countries like Madagascar, Chad or Iran, which see how scarcity affects their population hard. However, this climatic phenomenon is also increasingly affecting countries with much greater economic and technological capacity, such as United Stateswhich tries to prevent one of its biggest sources, the colorado riverrun out of water.
And it is that the climatic emergency in the form of long-term drought is beginning to drain the mythical riverwhich for many years reigned in the frontier imaginary of the Far West: The federal government declared a water shortage for the first time on Monday. on Lake Mead, one of the river’s main reservoirs. Specifically, the levels of this dam, the largest in Colorado, have fallen to about historic lows that allow a white ring of minerals to be observed along its perimeter, outlining the place where the high water line once stood.
The government decision will have immediate effects, since among other things water supply cuts are planned which, for now, will mainly affect the Arizona farmers. And it is that, as of January of next year, they will not be able to receive a large part of the water on which they have depended for decades, a situation that their counterparts in Nevada and New Mexico.
However, the greatest danger is that, if the situation does not improve, the declaration of scarcity motivates that in the coming years larger outages affecting the more than 40 million people in the west who depend on the river for at least part of their water supply, as the inexorable rise in temperatures that has occurred in recent decades could continue to reduce the amount of water flowing into the Colorado due to less rain and melting snow.
“As this apparent inexorable decline in supplythe scarcity that we are beginning to see implemented will only increase”, explains in the New York Times Jennifer Pitt, who runs the Colorado River program at the National Audubon Society. “Once we’re on that train, it’s not clear where it stops,” he notes with concern.
The decline of Lake Mead
At the center of this Colorado River crisis is Lake Mead, one of the largest dams in the United Statess that was formed by the construction of the Hoover Dam in the 1930s and is one of several man-made reservoirs that store water for domestic supply, irrigation for farms, and hydroelectric power in the states of Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming, and also parts of Mexico.
But the water levels in this reservoir and the lago Powell, the two largest dams on the river, have been falling for years and faster than experts predicted. Lake Mead now contains about 15,000 hm3 of water, well below its more than 37,000 hm3 capacity. The last time it was nearly full was two decades ago, and since then much of the Southwest has been engulfed in a drought that climate scientists say rivals some of the longest and most severe in the last 2,000 years.
In this way, scorching temperatures and less snow melting in the spring have reduced the amount of water flowing from the Rocky Mountains, where the river originates before winding 1,450 miles southwest toward the Gulf of California. “We are at a point where we are considering how we continue to prosper with less waterAnd it’s very painful.” explains the NPR Sarah Porterdirector of the Kyl Center for Water Policy at Arizona State University.
For the time being, attempts to control the drought without declaring scarcity have failed. Under a 2019 contingency plan, Arizona, Nevada, California and Mexico agreed to give up parts of their water to maintain water levels in Lake Mead, with a series of voluntary measures that have not been enough. And while the shortage announced Monday affects only the lower basin states, the Bureau of Reclamation appears to plan to declare a similar scarcity for the upper basin, maybe as soon as next year, as pointed out by Washington Post.
Furthermore, although in theory Lake Mead and Lake Powell could be filled relying on the aquifers of the area, “it would be more prudent to plan for a hotter and drier future with less river water,” Porter predicts. A challenge in which new techniques for harnessing and reusing water will have to play an important role: as neighboring California demonstrates, innovation can be an important solution at the level of water adaptation and also partially mitigate the most damaging effects of climate change.
Innovation against drought?
For the people of the state of California, the Colorado River crisis is just the tip of the iceberg for all your water-related problems. According A study spearheaded by the Natural Resources Defense Council (NRDC), California has traditionally been a region severely hit by extreme weather eventsespecially for those related to the high temperatures that have made the Water is a very precious and scarce resource..
Faced with this situation, Californians have opted for the reuse of water as the method par excellence to make the most of this resource. In fact, according to the NRDC, Californians have been reusing water for more than 100 years: In 1910, reused water was used in dozens of municipalities for agriculture and in the 1970s its use expanded to 215 hectometers cubic meters of municipal wastewater reused per year.
Currently, the amount of reused water is approximately 880 cubic hectometres of municipal wastewater reused per year. However, this figure becomes scarce in the face of the new scenario presented by climate change, which crystallizes in crises such as that of the Colorado River, and the demographic expansion of the region that will make more water is required for human use.
To meet this challenge, alliances and public-private collaboration they have become vital tools. After all, much of California’s innovation in greywater reuse would be impossible without the technological and economic drive provided by hundreds of companies throughout this state, the most populous in the US. In fact, there are already projects there that seek to develop direct drinking water reuse by 2023, which, in the words of Californian congressman Bill Quirkwill make the region one of the pioneers from the use of highly purified reclaimed water for the supply of human consumption.