Historic Drought Resulted in Declaration of Unprecedented Water Cuts for Colorado River
August 17, 2021
On Monday, the federal government declared a water scarcity on the Colorado River for the first time. This propelled compulsory water consumption cuts for the Southwest states, as drought caused by climate change pushes the water level in Lake Mead to an all-time low.
The largest reservoir in the US, Lake Mead has drained at an alarming rate this year. Approximately 1607 feet above sea level and 35% full, the Colorado River reservoir is at its lowest since the lake was filled after the inception of Hoover Dam in the 1930s.
The Colorado River also feeds the second largest reservoir, Lake Powell. The lake recently sank to a record low and is currently only 32% full.
Brad Udall, senior water and climate scientist at Colorado State University told CNN that it is very concerning. “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 US Bureau of Reclamation’s latest monthly projections, revealed that the lake is expected to remain at 1066 feet of elevation through 2022. Due to this, the agency announced that the Colorado River will go into the first tier of water cuts which will commence on January 1st.
The report stated that the Glen Canyon Dam and Hoover Dam downstream releases will be reduced in 2022 because of declining reservoir levels. This is spurred on by the ongoing historic drought and low runoff conditions in the Colorado River Basin
According to the National Park Service, Lake Mead supplies water to roughly 25 million people in Arizona, Nevada, California and Mexico. Arizona and Nevada will be affected by the tier-1 cut, under the complex priority system. Arizona will see an 18% decline in the state’s total Colorado River supply, predominantly affecting agriculture. John Entsminger, general manager of the Southern Nevada Water Authority said that even though Nevada will need to comply to the 7% reduction in its Colorado River water supply in 2022, the state had already reduced its supplies and no change is expected due to the scarcity. Additional cuts might be imposed with worsening impact on agriculture and municipal water if Lake Mead continues to fall. The second tier, activated at 1050 feet, cuts could be implemented as soon as 2023.
T.J. Atkin, a cattle rancher in Utah and Arizona, described the toll the drought was taking on his family's business and his animals. Atkin told CNN that the condition has not been this bad in 85 years and this is the first time they have been pushed to this extent.
US officials said at a news conference, announcing the cuts, that climate change is behind the West's water shortage.
According to a UN report released last week, droughts might occur once every 10 years globally. However, it occurs 70% more frequently now. The report also highlighted the role of human caused climate change plays in drought frequency and intensity. More than 95% of the West was in drought, the largest area in the history of US Drought Monitor.
Tanya Trujillo, assistant secretary for water and science at the US Department of the Interior said, "There's no doubt that climate change is real — we’re experiencing it every day in the Colorado River Basin and in other basins in the West." She weighs in further on how to tackle the situation by explaining that the best strategy is to think about a wide range of scenarios and a wide range of potential hydrology, working closely with partners in the basin to think through all of the possible scenarios.
According to a 2020 study by US Geological Survey scientists, the Colorado River’s flow has declined by approximately 20% over the last century. The researchers said that increasing temperatures across the basin has caused more than half the decline. The study found that Colorado River’s average discharge could diminish by 31% by the middle of the century, if there are no substantial reductions to planet-heating emissions, particularly from the burning of fossil fuels, when compared to the historical average.
The drastic consequences of the reservoirs' rapid decline cannot be overstated as the Colorado River supplies water to more than 40 million people living across 7 US states and Mexico. Lake Mead and Lake Powell are crucial sources of drinking water, hydropower and irrigation for many communities across the region including rural farms and tribal nations. Udall said the West should prepare for more shortages as the climate rapidly changes. He added that we are about to see the worst implications of climate change through the alteration in water cycle. He said cautioning that we have to plan for and pre-empt these undesirable water consequences by reducing greenhouse gas emissions proactively.