Lake Powell, the second-largest reservoir in the United States, just fell to its lowest water level since it was first filled in the 1960s. But the biggest threat comes when the water drops another 30 feet.

At that point, the lake hits what the Bureau of Reclamation calls "minimum power pool." If the water drops below the intake pipes, the massive turbines inside the Glen Canyon Dam will no longer be able to spin.

Breaking down the critical water levels

• Full pool: This is reached when waters are 3,700 feet above sea level and the dam is considered full because any more water would spill over the top.
• Target level: 3,525 feet above sea level is what water managers want to keep Lake Powell at or above in order to keep up normal hydroelectric operations and downstream releases.
• Minimum power pool: Once the waters sink to 3,490 feet above sea level, we start to have some concerns. This is the minimum level at which the dam can produce power.
• Dead pool: At 3,370 feet above sea level, water can’t move through the dam to the Colorado River anymore. Reaching this point would cause huge issues in terms of water and power supply.

Between the minimum power pool and dead pool levels, water can only travel through tunnels called "river outlet works." These bypass the turbines, meaning no power is produced, but the water is still dumped back out into the Colorado River.

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What happens if the Glen Canyon Dam shuts down

That would cut off the primary, low-cost electricity source for roughly 5.8 million homes and businesses across Wyoming, Utah, Colorado, New Mexico, Arizona, Nevada and Nebraska. Without the dam, those states would be forced to buy replacement power on the open market, which is more expensive and relies heavily on fossil fuels. 

The clock is ticking quickly. According to recent 24-month studies, Lake Powell is dropping by roughly two and a half feet a month. Even with emergency interventions, federal projections show the lake could hit minimum power pool by spring 2027.

The record-low milestone at Lake Powell comes just days after the Colorado River system's other anchor, Lake Mead, also plunged to a historic low. Together, the two reservoirs provide municipal water to 40 million people and irrigate the farmland that produces about 90% of America’s winter vegetables. 

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What has caused the low levels?

The crisis is driven by decades of overuse, but a very low snowpack and a warming region have accelerated the collapse. Warm temperatures are drying out the soil, causing what little snowmelt there is to absorb the water in the ground like a sponge before it can ever reach the river.

Earlier this year, federal officials warned the crisis was moving so fast that Glen Canyon Dam could lose power generation by the end of 2026. The Bureau of Reclamation managed to delay that deadline by slashing the amount of water released from Lake Powell to the lowest level in decades, and by pulling emergency water from Flaming Gorge, a smaller reservoir hundreds of miles upstream. 

Those moves bought the region a few extra months. But the federal government has made it clear to the seven states that rely on the Colorado River: they must agree on a plan for massive, long-term water cuts, or the government will step in and impose them.