In the 1960s, the Colorado River was dammed to form Lake Powell with the construction of Glen Canyon Dam on the Arizona-Utah border. When completely filled, the artificial lake has enormous dimensions: It is almost 300 kilometers long, about 170 meters deep at the Glen Canyon Dam, covers an area of over 650 square kilometers, which corresponds to about one and a half times the area of the city of Vienna, and contains over 33 billion cubic meters of water.
All of this is currently theory. According to the “WP” report, the fill level is just 22 percent. The reservoir was last completely full more than 20 years ago, in 2001. Eleven years later, the level dropped to around 60 percent, after the two dry and hot years 2020 and 2021 to around a third and in 2022 finally to below 25 percent. With the current low, there are growing concerns of serious problems for several states and millions of people in the Colorado Basin.
Water and electricity for millions of people
The reservoir is around 350 kilometers northeast of the desert metropolis Las Vegas (Nevada), the turbines on the Glen Canyon Dam, built from 1956, supply electricity for around 4.5 million people, the Colorado and its catchment area, according to “WP”, water for 40 million residents of the US Southwest in seven states.
Last week, the US newspaper wrote, the water level dropped to 3,522 feet (around 1,074 meters) above sea level, the lowest since the reservoir was filled in the 1960s.
The Old Law of the River
Drastic water management measures would now have to be taken in order to avoid “bad consequences”. There is too much demand and too little water supply, the US newspaper quoted hydrologist and climate researcher Brad Udall from Colorado State University (CSU).
The legal agreements on water use would have to be “largely rewritten”. With progressive use of the water from the Colorado, this was historically regulated in the “Law of the River” – numerous agreements between the states and with the government in Washington.
To a large extent, these simply no longer fit the time, according to expert Udall. “We are currently seeing a collision between 19th-century water law, 20th-century infrastructure and 21st-century demographic change and climate change.” Everyone can imagine how this will end.
A few meters to the failure of the turbines
Drought periods, “the chronic excessive use of water resources” and the climate crisis are affecting the Colorado, and the level in the reservoir is falling. If this falls from the current 3,520 to 3,490 feet, i.e. less than ten meters, the turbines on the Glen Canyon Dam could no longer run.
This problem is currently 32 feet (9.75 meters) away, according to expert Udall. And there have been years in the recent past “where we’ve lost 50 or more feet of storage volume.” That means: “We are a bad year away from reaching the point where we can no longer generate hydroelectric power.”
Similar problems at the country’s largest reservoir
Lake Powell is the second largest reservoir in the United States after Lake Mead, which is further south of Las Vegas and also fed by the Colorado River. Located on the Arizona-Nevada border, it is impounded by the Hoover Dam, built in the 1930s. Lake Mead struggles with similar problems as Lake Powell.
From a water level of 3,370 feet (around 1,027 meters) above sea level, the reservoir becomes a “dead” lake, according to the “WP” report, which means that in the worst case the water in it can not flow further downstream and entire regions from the supply threatened to be cut off. Again, one can imagine the possible consequences, so Udall. The reservoir supplies 90 percent of the people of Las Vegas, half of Phoenix, Arizona, and holds a quarter of the water volume of the Los Angeles Basin.
So far no solution
Attempts have already been made to add water to Lake Powell from upstream reservoirs and to slow the flow, but neither have had any lasting success.
In the long term, only drastic measures to limit water consumption would help. This requires consensus among the seven states that use the Colorado River and its waters – California, Arizona, Colorado, Nevada, New Mexico, Utah and Wyoming. So far, however, no agreement has been reached.
