The Suffering River Due to Drought: First Ever Water Cuts Declared for Colorado River

5th September 2021

The federal government on 16. August declared a water shortage on the Colorado River (around 40 million people in the US and Mexico rely on the river for water) for the first time, triggering mandatory water consumption cuts for states in the Southwest.

Climate change-fueled drought cause unprecedented lows in Lake Mead, one of the basin’s largest reservoirs in the US by volume.

The reservoir has drained at an alarming rate this year. At around 1,066 feet above sea level and 35% full.

It is at its lowest water level since the lake was filled after the Hoover Dam was completed in the 1930s (concrete placement in the dam was completed May 29, 1935).

Annual elevation diagram of Lake Mead made by Szilvia Kullai

Find all data about end of month elevation of Lake Mead at Hoover Dam, supplied by Bureau of Reclamation Records below in the link:

The reservoir, which was created near Las Vegas after the building of the Hoover Dam holds water for cities and farms in Arizona, Nevada, California and Mexico. The lake's rapid decline has been outpacing projections from just a few months ago and not it is so parched and depleted that Mead is projected to continue dropping next year and into 2023.

In 2000, Lake Mead was nearly full, and its surface was lapping at the spillway gates of the Hoover Dam. Since then, the reservoir has fallen nearly 143 feet (~43,5 m). And it's now at the lowest levels since 1937.

Hoover Dam aerial view from the year 2000 by Lynn Betts on Wikimedia

To compare the current and previous water-levels you can take a look of the intake towers, how highly rise it out now from the river or the minerals deposition on the rock walls above the lake.

Hoover Dam Diagram by Jarek Tuszynski on Wikimedia
Photo by Ricardo Frantz on Unsplash
Photo by Ricardo Frantz on Unsplash

"This is like a different world," said Pat Mulroy, the former head of the Southern Nevada Water Authority.

“We are in the twenty-second year of drought and the lake was about 95% full in year 2000, and now we are at 35%.” says Patti Aaron, Lower Colorado Regional Public Affairs Officer at Bureau of Reclamation and continued− “we have a decrease of about 25% of our capacity in producing power because of the lower lake levels.”

For the comparison of the drought situation here are two maps from the years 2001, and 20 years later, from 2021.


U.S. Drought Monitor Maps. Authors: (2001) David Miskus, NOAA/NWS/NCEP/CPC

(2021) Curtis Riganti, National Drought Mitigation Center

Here is another remarkable illustration from Google Earth Timelapse about the drought condition.

Google Earth Timelapse photos from the years 1984 and 2020.
Google Earth Timelapse photos from the years 1984 and 2020.

“Even if it would be the same wetness as what happened in the 1980s, now we have got warmer temperatures and those are just going to evaporate off more of water, create more water demand.” −Matthew Lachniet, Paleoclimatologist.

Although the water is use 90% by agriculture, we are not allowed to forget that the growth population also add to the water shortage.

Figure of the percent change in resident population and diagram of the growth for the last twenty years.

“We are seeing the effects of climate change in the Colorado River basin through extended drought, extreme temperatures, expansive wildfires, and in some places flooding and landslides. And now is the time to take action to respond to them,” said Tanya Trujillo, Department of the Interior assistant secretary for water and science.

That includes speeding up efforts that cities and water agencies are already undertaking in parts of the Southwest, such as investing in recycling wastewater, capturing stormwater or cleaning up polluted groundwater, said Felicia Marcus, a visiting fellow at Stanford University’s Water in the West program.

Brad Udall, senior water and climate scientist at Colorado State University, told to CNN. "It's something that those of us in the climate community have been worried about for over a decade, based on declining flows due to climate change."

The lower basin was already in a Tier Zero shortage this year, which required modest reductions in water withdrawals from the river by users in Arizona, Nevada, and Mexico. Even so, total water storage in the basin’s reservoirs dropped from 49 percent of capacity at this time last year to 40 percent today.

With the lake expected to remain at around 1,066 feet of elevation into 2022, according to the US Bureau of Reclamation's latest monthly projections, the agency announced that the Colorado River will go into the first tier of water cuts beginning January 1.

"Given ongoing historic drought and low runoff conditions in the Colorado River Basin, downstream releases from Glen Canyon Dam and Hoover Dam will be reduced in 2022 due to declining reservoir levels," the report said.

According to the National Park Service. Under the complex priority system, Nevada and Arizona will be affected by the tier-1 shortage.

Although Nevada will need to adhere to a 7% reduction in its Colorado River water supply in 2022, the state had already reduced its deliveries and no change is expected due to the shortage, according to John Entsminger, general manager of the Southern Nevada Water Authority.

Mexico will see a 5 percent reduction, and Arizona will have its allocation slashed by 18 percent. Farmers in the last-mentioned area will be the first to feel the pain of the cuts. In one county, farmers will receive 65 percent less water next year.

That will shrink the amount flowing through the Central Arizona Project Canal to farmlands in Pinal County that produce alfalfa, cotton, wheat and other crops. Farmers in Pinal plan to pump more groundwater from newly drilled wells, but they’ll still be short with the loss of Colorado River water and are planning to leave some farmlands dry and unplanted over the next couple of years.

Officials from Arizona, Nevada, California and Mexico have been talking about other ways they might work together on long-term projects to shore up water supplies. One idea they’re studying would be for Arizona to work with Mexico to build a desalination plant on the shore of the Sea of Cortez and trade some of the drinking water that’s produced for a portion of Mexico’s Colorado River water.

One more interesting video:

Remembering the last time Lake Mead was full

Szilvia Kullai