Could the Mississippi River Refill Lake Mead’s Massive Reservoir?

Written by Drew Wood
Updated: October 29, 2023
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Lake Mead, the largest reservoir in the United States, was created by the construction of Hoover Dam on the Colorado River, situated on the border between Nevada and Arizona.

Key Points

  • Lake Mead has dropped by 70% due to droughts in the West, and it will take many years to refill again through entirely natural means.
  • The reservoir is vitally important to millions of people as a source of water, electricity, and recreation.
  • Developing new technologies in water desalinization and cheaper and more sustainable energy sources may offer a better long-term solution than building a large water pipeline.

The Western U.S.A. struggles with a perennial lack of water. But this isn’t a new problem. Geologic and tree ring data show that California has gone through significant periods of drought for at least 1,000 years.

Droughts in recent decades have been particularly severe, perhaps related to climate change. The dry spell of 2000-2018 was the second worst drought the state experienced in the previous 500 years. Lake Powell and Lake Mead, both located on the Colorado River, are the two largest reservoirs in the United States. They have been at record low levels, affecting water supplies and electricity-generating capacity.

A frustrating aspect of this problem is that the Eastern United States has more than enough water to supply the whole country. At the mouth of the Gulf of Mexico, the Mississippi River discharges 4.5 million gallons of water per second. California needs about 430,000 gallons per second. Thus, the Mississippi is “wasting” 10 times more fresh water every day than what California needs. So, could the Mississippi River refill Lake Mead’s massive reservoir?

Lake Mead

Recent years of drought have caused the water level at Lake Mead to drop precipitously.


The Importance of Lake Mead


Without irrigation, farmland like this in California and other western states would revert to the desert.


Lake Mead is a man-made reservoir that was formed after Hoover Dam was built across the Colorado River on the border of Nevada and Arizona. It is the largest reservoir in the U.S. When fully filled, it is 112 miles long and 532 feet deep. Its 28.23 million acre-feet of water serves the needs of 20-25 million people. It also irrigates large areas of farmland in Arizona, California, and Nevada. Besides this, Hoover Dam provides four billion kilowatt-hours of electricity to 1.3 million people. Keeping the reservoir full is important to keep the taps running and the lights on. Additionally, the value of the lake as a vacation spot brings funds into the local economy. The lake provides recreation for local people and tourists, including the millions of residents and visitors of Las Vegas only 40 minutes away.

Since 1983, years of drought along with high water demand have caused the lake to drop by 132 feet. Today, the lake is at only 30% capacity, its lowest level since it was built in the 1930s. Fortunately, heavy rainfall early in 2023 has relieved the situation a little, but only temporarily. It’s not ideal for a lot of rain to fall all at once. It causes catastrophic flooding, and much of the water runs off rather than soaking into the land or filling reservoirs. About 60% of the area still is in drought. It would actually take six more years of heavy rainfall in a row to refill the Lake Mead reservoir completely. Time is ticking to solve the problem before future droughts dry up the lake completely.

How Could the Mississippi River Refill Lake Mead?

For years, the idea of diverting water from the Mississippi River to the parched west has been discussed. Similar ideas for piping water south from Alaska and Canada have also been mentioned. But the idea was supercharged in 2021 when the Arizona state legislature passed a resolution to urge the U.S. Congress to do a serious study of the plan’s feasibility. As crazy as it sounds, engineers say the idea is technically feasible. It would involve building a system of dams and pipelines to move the water uphill across multiple states over the Continental Divide. Gravity would then work in our favor to drop the water down to the Colorado River watershed.

It doesn’t exactly involve any radically new technology, but the scale of it would be unprecedented. It’s estimated the pipeline would have to be 88 feet in diameter, which is twice the length of a semi-truck trailer – remember, that is the pipe’s diameter! It could also work with a channel 100 feet wide and 61 feet deep. Either of those would be large enough to put a typical suburban home on a raft and float it to the Rockies! And the whole system might have to cross 1,000 miles to get the job done.

Mississippi Delta

In the Louisiana Delta, the Mississippi River discharges 4.5 million gallons of water per second into the Gulf of Mexico. This unused water is 10 times the water needs of California!


What Would It Cost?

The Mississippi River could refill Lake Mead, but should it? A project like this would come at a tremendous cost, in hundreds of billions of dollars. Even if the cost of the imported water worked out to a penny a gallon, it would cost $134 billion to refill both Lake Mead and Lake Powell. However, a study of the feasibility of pumping water from Alaska down the West Coast was conducted. It determined that this project would get water to California at a cost of about five cents per gallon. If that were the case in the Mississippi scheme, that project would easily cost more than $500 billion. The project would require purchasing private property for the pipeline route across multiple states. The construction would have to pass environmental impact studies. And even after it was built, it would incur annual costs for operations and maintenance.


Maybe even more difficult than the technical and financial issues is the political hurdle. Getting states of different political perspectives to agree on a project like this is next to impossible. It could ultimately increase the population, economic growth, and political clout of Western states, something some Eastern states would not like to do in today’s political climate. Even if all those hurdles were surmounted and construction began today, it would take about 30 years to complete. The first drops of water would not start flowing until the mid-2050s. It’s at best a future solution that requires heavy up-front costs, both financially and politically. However, it doesn’t really pay off for the affected states for years to come.

Imagine a pipe like this, 10 times larger, pumping water a thousand miles from Mississippi to Colorado. Is this really the best answer?


What About the Environmental Impact?

In addition to the financial and political investments, serious environmental damage is a real possibility, both in the areas exporting water, and those importing it. There are a lot of different habitats and species of birds and wildlife down the whole length of the Mississippi and its tributaries. Significantly lowering the water level could drain wetlands and decrease biodiversity. It could also slow down the flow of the river so that more silt would settle out along its route and lower the river’s depth in shallow places, requiring more dredging in different places to keep the channel open and safe for cargo vessels.

Impact on the Mississippi River Watershed

Moreover, the water that flows from the Mississippi into the Gulf of Mexico is not “wasted.” It takes soil, nutrients, and warmer water out into the gulf, affecting the natural balance of marine life there. Lower freshwater levels near the mouth of the river could allow salt water to move further up the Delta, poisoning the swamplands and what lives in them. Changing sea water temperature by significantly diverting warmer river water, if done on a large enough scale, may have unpredictable effects on ocean currents and even the local climate.

Finally, from time to time, there are drought conditions in the Mississippi basin, as recently as of 2022. In such years, states in the region may not feel they have water to spare. This problem could be mitigated by drawing water from near the mouth of the river before it dumps into the Gulf. However, this would add greatly to the length of the pipeline and raise the danger of contamination of the water supply during hurricanes or other flooding events.

Bogue Chitto National Wildlife Refuge
The Mississippi River ecosystem could be damaged if significant amounts of water were diverted.

Impact on the Colorado River Watershed

The environmental damage would not be limited to the areas exporting water. The Colorado River watershed could also see damage in several ways. First of all, the water of the Mississippi River is not exactly pristine. It drains millions of acres of farmland and runs through industrial cities. Many thousands of vessels of all sizes navigate on it daily, leaving behind a polluted residue of all sorts. Water sent west would contain traces of pesticides, industrial chemicals, organic pollutants, and excessive nutrients that would change the composition of the Colorado River. This could make it a more hostile environment for the species that currently live in and around it.

Invasive Species

Invasive species are another major concern. Zebra mussels, round gobies, rusty crayfish, Asian carp, and faucet snails are some of the most notorious invasive species in the Mississippi. A great deal of effort and expense has gone into trying to prevent Asian carp from traveling through canal systems into the Great Lakes. The problem with this species would be multiplied exponentially if we piped billions of gallons of infested Mississippi River water into the Colorado River system. In addition to this, many of the Mississippi’s own indigenous species, if accidentally transported to western rivers and reservoirs, would become invasive species there. To the extent that some of them might outperform local species, biodiversity would be reduced and more species might become endangered.

Unsustainable Development

A final consideration, environmentally, is that without human intervention, western lands would have arid or desert habitats with the appropriate plants and animals for the level of water available in their environment. It is the choice of enormous numbers of human beings to live in areas that do not have sufficient resources to support them that has created a huge water deficit. Solving that problem with a big pipeline might just encourage many more people to live in places where a massive human population is unsustainable.

Sunny Day in Denver Colorado, United States. Downtown Denver City Skyline and the Blue Sky.

Some of the Western U.S. has large populations packed into small areas without sufficient resources.

©Virrage Images/

Alternatives to River Diversion

As discouraging as this picture might seem, solutions may not be so radical, expensive, or far off. Water conservation and recycling can do a lot. Part of this will take cultural change. For example, residents in the West will need to abandon the suburban American tradition of maintaining a perfectly manicured (and well-watered) green yard. Given the resources it wastes, the rest of the country should abandon this as well. An alternative is “xeriscaping” – landscaping with indigenous desert plants, sand, and rocks in dry areas rather than irrigating. In more well-watered parts of the country, many homeowners choose to naturalize portions of their yards with indigenous plant species to lower the time and expense of maintenance and provide cover for wildlife.

Raising the cost of using water in the West can help people make some tough decisions about what is essential and what is not. Maintaining private swimming pools, for example, may become more of a luxury and less of an expectation when buying or selling a suburban home in the West. Water restrictions are understandably hugely unpopular, but over time they can help motivate people to flee congested, expensive, and rule-bound urban areas for other parts of the country where resources are not so scarce. Arizona is actually a success story in water conservation. As of 2017, the state was actually using less water than it did in the 1950s, even though the state population has grown 700% from one million to almost seven million people today.

Streetview of a suburban home with xeriscape landscaping.

This is an example of xeriscaping – landscaping with desert plants and rocks.

©PT Hamilton/

What’s the Answer?

A problem this complex will take a multi-faceted solution. Could the Mississippi River refill Lake Mead? Technically, yes. Would we want it to? Maybe not. The financial, political, and ecological costs will be so high that this is unlikely to be a feasible solution. If we want a technological fix, the same investment devoted to researching more cost-effective seawater desalination and alternative energy sources like solar or even fusion power could help lower the costs of providing water and electricity. Time will tell. But one thing we know from human history: we are certainly the most adaptable survivors of any species on Earth. The same skills that have enabled us to live in every habitat on the planet and even start exploring space will enable us to adjust to environmental changes and continue to survive and thrive.

What Can the Average Person Do to Conserve Water?

King of the Iowa Feedlot

Every 2 pounds of beef takes nearly 4,000 of water to produce. Reduce meat consumption to help with drought and climate change.

©DarcyMaulsby/iStock via Getty Images

The average person or household can make a significant difference in the fight against drought by reducing or eliminating their meat consumption. This is because the production of animal products utilizes more water than any other agricultural product. For example, it takes about 4,000 gallons of water to produce 2 pounds of beef, while it only takes 132 gallons of water to produce 2 pounds of wheat. Even 1 pound of chicken takes 529 gallons of water to produce, and pork takes 718 gallons. In contrast, it takes only 250 gallons of water to produce a pound of soybeans.

Raising animals for meat also contributes to global climate change by releasing large amounts of greenhouse gases into the atmosphere. Livestock farming is estimated to be responsible for 14.5% of all human-induced greenhouse gas emissions. Furthermore, livestock farming and the growing of feed crops are responsible for 70% of all agricultural land use, resulting in deforestation and soil erosion.

It is easy to see how reducing or eliminating meat consumption can have a major impact on drought. Plant-based diets can reduce water consumption, land use, and greenhouse gas emissions. Therefore, reducing or eliminating meat consumption is a great way for individuals and households to make a big difference in fighting drought and climate change.

The photo featured at the top of this post is © Milen Mkv/

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About the Author

Drew Wood is a writer at A-Z Animals focusing on mammals, geography, and world cultures. Drew has worked in research and writing for over 20 years and holds a Masters in Foreign Affairs (1992) and a Doctorate in Religion (2009). A resident of Nebraska, Drew enjoys Brazilian jiu-jitsu, movies, and being an emotional support human to four dogs.

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