Lake Mead and Lake Powell Water Levels Continue to Drop to Historic Lows

The Ongoing Crisis at Lake Mead and Lake Powell

Lake Mead and Lake Powell, the two largest reservoirs on the Colorado River, have been facing an unprecedented water crisis in recent years. Water levels at both lakes have dropped to historically low levels, threatening water supplies for tens of millions of people in the Western United States.

Causes of the Declining Water Levels

There are several factors that have contributed to the sharp decline of water levels at Lake Mead and Lake Powell:

• Overallocation of the Colorado River - More water has been allocated to states and Mexico from the river than the total amount of water that actually flows in it. This has created an unsustainable situation, especially during drought years.
• Ongoing drought - The Western U.S. has experienced below average rainfall and snowpack levels for most of the past two decades. This has limited runoff and inflows into Lake Mead and Lake Powell.
• Increasing temperatures - Higher temperatures lead to more rapid evaporation and transpiration by plants, decreasing overall water availability in the Colorado River Basin.
• Rapid growth - Population growth in the Southwest has increased demands on the already overallocated Colorado River.

The Dropping Water Line at Lake Mead

Lake Mead, located on the border of Nevada and Arizona, is the largest reservoir in the United States. It was last full in 1983. Since 2000, water levels at Lake Mead have dropped approximately 140 feet. As of January 2023, Lake Mead's water level stood at around 1,045 feet above sea level, about 157 feet below its full capacity.

In June 2021, Lake Mead's water level fell below the federal shortage threshold of 1,075 feet for the first time. This triggered mandatory water cuts for Arizona, Nevada and Mexico starting in 2022. Experts warn that if Lake Mead continues dropping, it could hit "dead pool" levels, where water would no longer flow downstream.

Lake Powell Also Sees Record Lows

Meanwhile at Lake Powell, located upstream on the Colorado River along the Arizona-Utah border, water levels have also been falling dramatically. Lake Powell is currently at around 3,522 feet, the lowest level since it initially filled in the 1960s.

In 2022, Lake Powell's level dropped below a critical threshold of 3,525 feet. This led to the shutdown of Glen Canyon Dam's hydroelectric power generation for the first time ever. Power generation resumes when water levels rise again.

Impacts on Water Supplies

The dropping water levels are leading to significant cuts in water allocations for states that depend on the Colorado River. In 2022, the Bureau of Reclamation implemented a Level 2 Shortage Condition for Lake Mead, requiring Arizona to take an 18% cut, Nevada 8%, and Mexico 7%. Further cuts are expected in the coming years.

If Lake Mead continues to fall, more severe shortage levels will be declared leading to even deeper reductions. Las Vegas in particular is scrambling to find alternative sources of water as over 90% of its supply comes from Lake Mead.

Environmental Impacts

The lowering water levels are also negatively impacting the environment around Lake Mead and Lake Powell. Less water means loss of habitat for fish and wildlife. Declining lake levels have also exposed more ground to air, increasing dust levels in the region.

Exposed lake bed sediment can be picked up by winds, sometimes carrying harmful pesticides and fertilizers. At Lake Powell, receding waters have led to several native fish die offs when warmer water became trapped in side channels.

Efforts to Address the Crisis

Water agencies across the West are scrambling to deal with the rapidly developing crisis at Lake Mead and Lake Powell. Efforts underway include:

• Water conservation programs to reduce demand and waste.
• Restricting agricultural water transfers.
• Cloud seeding to try to increase snowpack and runoff.
• Construction of desalination plants and wastewater recycling.
• Negotiating the voluntary sale of water rights.
• Drilling new wells to access groundwater.

However, many experts state these efforts are like "rearranging deck chairs on the Titanic" unless the fundamental issue of overallocation on the Colorado River is addressed. Difficult negotiations are underway between states to try to reduce water use and stabilize the system.

Outlook Remains Grim

Unfortunately, the outlook for Lake Mead and Lake Powell remains extremely concerning. Climate change models predict the Southwest will continue getting hotter and drier, meaning less Colorado River water availability.

The reservoirs may see brief periodic improvements if the region receives some good precipitation years. But the overall long-term trajectory is continuing decline unless bold corrective action is taken. The water security of 40 million people ultimately depends on finding solutions for the shrinking Colorado River and its critical reservoirs.

FAQs

How much have water levels declined at Lake Mead and Lake Powell?

Since 2000, water levels at Lake Mead have dropped around 140 feet. Lake Powell has declined around 150 feet since its initial fill in the 1960s.

What is causing the water levels to drop?

The main factors are overallocation of the Colorado River, ongoing drought, increasing temperatures due to climate change, and continued population growth in the Southwest.

What are the impacts of the declining reservoir levels?

Lower water levels are forcing cuts in water allocations for states relying on the Colorado River. There are also environmental impacts from loss of habitat and increased dust. Power generation at Glen Canyon Dam has been interrupted.

What efforts are being made to address the issue?

Water agencies are implementing conservation, restricting transfers, cloud seeding, desalination, wastewater recycling, well drilling, and negotiating voluntary water right sales. Discussions are underway to reduce allocations.

What is the future outlook for Lake Mead and Lake Powell?

The long-term outlook remains very concerning, with climate models projecting a hotter, drier Southwest. The reservoirs may see periodic improvements but overall decline is expected without major interventions.