The two largest reservoirs in the United States, Lake Mead and Lake Powell, are currently at their lowest level ever, leading to water and power shortages in the Western United States, in due to the climate crisis and overconsumption of water, according to experts from the United Nations Environment Program (UNEP).

These two huge reservoirs provide water and electricity to millions of people but may soon reach the status of “dead pool” (dead pool, in English); in other words, a water level so low that the valves of the hydroelectric turbines would no longer be submerged, resulting in their total shutdown, and thus the production of electricity.

Lake Mead Reservoir, the largest man-made body of water in the United States, located in Nevada and Arizona, was created in the thirties with the construction of the Hoover Dam, a masterpiece of engineering. Lake Powell, second only to Mead in terms of water capacity, extends into Utah and Arizona. It was created in the 1960s with the construction of the Glen Canyon Dam.

• Water restrictions may not be enough:

The Mead and Powell dams not only provide drinking water and electricity to tens of millions of people – in the state of Nevada, Arizona, California, Wyoming, Colorado, New Mexico and in the neighboring country of Mexico – but also irrigation water for agriculture.

Experts warn that as the crisis worsens, water restrictions will have to be implemented, but this may prove insufficient.

“The regulation and management of water supply and demand is obviously essential in the short and long term, but the heart of the problem is climate change,” said the UNEP Ecosystems Officer in North America, Maria Morgado. “In the long term, we need to tackle the root causes of climate change as well as water demands. »

Over the past twenty years, 90% of major disasters have been caused by floods, droughts and other water-related events. Due to the increased frequency of droughts, people in water-scarce regions will increasingly depend on groundwater, due to its absorptive capacity and resilience to climatic variations.

“Weather patterns in the western United States around the Colorado River Basin have been so dry for more than 20 years that we are now beyond drought,” said UNEP ecosystems expert Lis Mullin Bernhardt. “We speak of aridification to define this new level. »

• “Perfect Storm”:

The increase in water demand, due to population growth and irrigation for agriculture, has been compounded by the effects of climate change, such as reduced rainfall and increased temperatures. The rise in temperature leads to an increase in the evaporation of surface water, a warming of the soil and a decrease in its humidity.

“These conditions are alarming, especially in the Lake Powell and Lake Mead area,” Ms Morgado added, saying all the conditions were in place for a “perfect storm”.

• The trend is global:

The danger of disappearance faced by these two reservoirs in the American West is to be included in a global trend affecting hundreds of millions of people. As climate change takes its toll, drought and desertification are fast becoming the new normal, from the United States to Europe to Africa.

Drought in numbers, a 2022 report by the United Nations Convention to Combat Desertification found that since 1970, weather-, climate- and water-related hazards have accounted for half of all natural disasters s being slaughtered on the planet, and have impacted 55 million people every year worldwide. The report also states that 2.3 billion people face water stress every year.

• Between 20 and 40% of the planet’s land qualified as “degraded”:

Drought is also one of the many factors influencing land degradation. Between 20-40% of the world’s land is classified as ‘degraded’, affecting half of the world’s population and affecting croplands, drylands, wetlands, forests and grasslands.

The United Nations Decade of Ecosystem Restoration, of which UNEP is a leading member, was set up to halt and restore ecosystems around the world. It will be held until 2030, the same deadline as the Sustainable Development Goals (SDGs), and aims to combat climate change and the collapse of biodiversity by restoring ecosystems.