In 1935, President Franklin D. Roosevelt dedicated Boulder Dam on Colorado River, now Hoover Dam at Arizona-Nevada border is part of feud between states due to climate change

Hoover Dam on the Colorado River at the Arizona-Nevada border has been a symbol of American fortitude and technological prowess. President Franklin D. Roosevelt commissioned it during his tenure in 1935. Back then it was known as Boulder Dam. For most of the 20th century, water use stayed well below what the Colorado River system carried. Dams such as Hoover dam and subsequently Glen Canyon dam in 1964 created Lakes Mead and Powell — below and above the Grand Canyon — generating hydropower and functioning together as one giant reservoir.

However, situation has turned bad to worse as the two largest reservoirs in the United States have fallen to record lows as a severe drought grips the country's West, according to reports by Reuters and other news outlets.

Colorado River - A Lifeline for 40 Million People


The new records highlight the difficulties fueled by climate change facing the Colorado River, a crucial resource for 40 million people. The river feeds both Lake Powell and Lake Mead, two reservoirs created by massive dams built to distribute water year-round and generate electricity. Their water levels are now just above the threshold at which electricity production would be affected.

The seven states that depend on the Colorado River have been arguing for years about how to share the river's water without being able to reach an agreement. The impasse forced the Trump administration to act as arbiter, unveiling a plan at the end of July that includes significant restrictions to address the drought threatening the river.

American States and Their Requirement

The new plan allows the administration to impose restrictions on California, Arizona and Nevada, requiring them to reduce their collective water consumption by up to 3.7 billion cubic meters per year until 2036 -- the equivalent of 1.5 million Olympic-sized swimming pools.

It does not require major efforts from Colorado, Utah, Wyoming, and New Mexico, the other states that depend on the river. This disputed imbalance could lead to a legal battle, and Arizona has already set aside several million dollars for potential lawsuits.

Last winter saw the worst snowpack on record for the Colorado River Basin, adding more stress on farmers, industry, wildlife and hydropower producers, as well as tens of millions of people who rely on the waterway, including in dozens of Native American tribes and in two Mexican states.

Years of overuse combined with drought and rising temperatures due to climate change have depleted the country’s two largest reservoirs, which are both fed by the Colorado. Lake Mead recently plummeted to its lowest level since it began filling nine decades ago, and Lake Powell did the same about a week later. Their combined storage is the lowest it has been in nearly seven decades.

Negotiators in Arizona thanked California and Nevada for their collaboration on sharing the cuts.

Colorado River system - How Does It Function?

The Colorado River system has about 60 million acre-feet of reservoir storage capacity, more than four times its average annual natural flow of 14.9 million acre-feet during the 20th century. That annual flow fell to about 12.3 million acre-feet from 2000 to 2025, reflecting prolonged drought and a warming climate.

The river’s reservoirs, chiefly Lake Mead and Lake Powell, have worked like liquid bank accounts — filling in wet years and paying out when snowmelt fell short of what the math demanded.

When full, Lake Powell and Lake Mead store roughly 80 per cent of all reserved water in the Colorado River system. They function essentially as one large savings account, with Powell feeding Mead water from upstream to then feed water to the lower basin. These dams supply power for up to 1.5 million households across seven states.