For the first time since its construction in the 1930s, Lake Mead is officially facing a shortage, US authorities said on Monday. The largest artificial reservoir in the country, fed by the Colorado River, will therefore be affected by restrictions.
The agency responsible for managing water resources has just published its forecasts for the next 24 months and the prospects are very worrying: by the end of the year, this gigantic reservoir attached to the Hoover Dam, near of Las Vegas, will have reached its lowest level since its inception. Currently, the lake’s reserves have dropped to around 40% of their capacity compared to 49% a year ago.
Also fed by the Colorado, Lake Powell, the second largest reservoir in the United States, recently reached its lowest level ever recorded, at only 32% filling rate. This poses a threat to the electricity generated by the Glen Canyon Dam, which generates some 5 billion kilowatt hours of electricity each year.
Restrictions that threaten farmers
As a result, federal authorities have announced that they will implement restrictions starting in October for states located downstream of Lake Mead, which will impact millions of consumers, including farmers. Arizona will thus receive regarding 18% less water compared to a normal year, Nevada 7% less and Mexico, where Colorado ends its run, 5% less.
In Arizona, these cuts represent regarding 8% of state consumption, note Axios, adding that farmers may face tough choices, such as leaving their fields fallow or tapping already dwindling groundwater supplies.
Faced with this situation, the governors of ten states in the west of the country called on President Joe Biden to officially declare a drought situation in their states, which would allow farmers to apply for new emergency aid.
The flow of the river has dropped by 20% for a century
Cracked soils as far as the eye can see, dry rivers… The western United States, from Utah to California via Nevada, is hit by an exceptional drought, “one of the driest periods of the 1,200 last years ” according to an official of the Ministry of the Interior. The latest official data shows that 99% of the west of the country is in a drought situation, compared to 63% a year ago, a situation that affects 59.2 million people.
This lack of rainfall “threatens to wipe out entire livestock operations, plummet yields and foster extreme levels of pests and disease that will magnify cumulative losses,” the governors wrote in their letter to Washington.
While Lake Mead is a key element in the water supply of 25 million inhabitants of Los Angeles, San Diego, Phoenix and even Las Vegas, the flow of the Colorado River which feeds it has dropped by an average of 20% for a century, and at least half of this drop can be attributed to rising temperatures in the area, according to a study published last year by the US Geological Survey (USGS).
“Globally, 800 million people are at risk of chronic water scarcity due to the drought caused by a warming of +2°C”, recently recalled a draft report from the IPCC, the UN climate experts. .
