11 Reasons Diverting the Mississippi River to California is a Bad Idea

California and other western states have suffered from periods of extreme drought for at least a thousand years. But at no point in their history have the stakes been so high as they are today. From 2000-2018, the state went through the second-driest period in its history, since the 1500s. As a result, the two largest reservoirs in the country have dropped by 70%. These are Lake Powell and Lake Mead. This puts 10s of millions of people in seven states at risk of losing drinking water and electricity generated by hydroelectric power. With all of this, it seems a natural solution to divert the Mississippi River’s water to the Colorado River. This is technically feasible, but a lot of people think it’s a really bad idea. Let us explain why.

Who Cares if Lake Mead Goes Dry?

Hoover Dam is an artificial human construction. Before the 1930s, Lake Mead didn’t exist. In its place was a natural gorge with the Colorado River flowing through it. In recent years, dams are being removed to allow fish to spawn and nature to take its natural course again. So, why not do the same with Lake Mead?

In the Lake Mead region, 20-25 million people depend on water and electricity generated by the lake to continue living in arid parts of the country that otherwise would never be able to support such a large population. Would you like to pay twice as much for fresh produce imported from other countries? That’s what might happen if there isn’t enough water to keep millions of acres of fruits and vegetables alive in California and other parts of the west.

Doing nothing isn’t an option. And waiting around for nature to solve the problem for us is unlikely to help. Researchers estimate it would take at least six years of above-average precipitation to completely fill the reservoir. Given the region’s history of drought, this doesn’t sound like a good bet.

Is Diverting the Mississippi River a No-Brainer?

California and the rest of the west have to have water, as it benefits the whole country. The east has more than enough water, with the Mississippi River draining the entire central part of the country. Every second it pours 4.5 million gallons of fresh water into the Gulf of Mexico. Only a 10th of that would provide for all of California’s needs.

Diverting this water to the west would require building a system of pipelines, water channels, pumping stations, and reservoirs to transport millions of gallons to the Continental Divide in the Rocky Mountains. From there, gravity would work to take the water into the Colorado River watershed. Simple, right? Not so fast.

Problems With Diverting the Mississippi

Diverting the Mississippi is a cool, science-fiction, geoengineering solution to a big problem, but it could create bigger problems than it solves. Here are just a few:

1. It’s Too Expensive

Providing enough water would take a pipeline 88 feet in diameter or a channel 100 feet wide and 61 feet deep. Either one of those would be bigger than an average house. The cost could be anywhere from $130-500 billion. In the end, it may be cheaper to pay half the people served by Lake Mead to relocate to better-watered parts of the country.

2. It Would Take Too Long

A project like this would take about 30 years to build, so even if construction began today, water would not start flowing until the 2050s. By then, Lake Mead may be nothing but a dust bowl with a creek running through it. What will we do to provide for their needs during those years of construction? And if they work for three decades, why couldn’t they continue to work indefinitely?

3. It Requires Huge Political Cooperation

Because the project crosses so many different states and jurisdictions, it would require unprecedented political cooperation at every level of government. And it would be a hard sell because so many of the costs would come on the front end, but the benefits wouldn’t be seen for 30 or more years in the future. For politicians whose terms of office will expire before then, it may not seem like the political hill they want to risk their careers on.

4. The Distance Would be Huge

The pipeline might have to traverse as much as 1,000 miles of varied terrain, going uphill most of the first half of its journey. Additionally, it will require ongoing maintenance for the indefinite future. And construction of it will require buying and condemning billions of dollars of private property, a hugely controversial step.

5. It is a Potential Security Threat

The drinking water and electricity supply for millions of people, farms providing food, and job-creating industries runs through a chokepoint across thinly populated areas of several states. At any point along that distance, an act of sabotage or war could immediately put the lives of 10% of Americans at risk.

6. It May Damage the Economies of Mississippi River States

If substantial amounts of water are taken out of the river, it will reduce the water flow, causing silt to settle out of the water earlier than it otherwise would. This will require additional investment and effort to dredge the river bottom and keep it deep enough for navigation. If the region has its own drought, as it did in 2022, there may not be enough water to meet the needs of the heavily populated and agriculturally intensive Midwestern heart of the country.

7. It Would Do Environmental Damage to the Mississippi Ecosystem

By decreasing the water flow in the Mississippi, this project would endanger wetlands, swamps, and the birds and animals that live there. Endangered species could go extinct, and other common species could become endangered. A reduced water flow could allow salt water to contaminate the river’s delta, killing plants, fish, and animal species.

8. It Could Alter the Gulf of Mexico Ecosystem

Cutting down the flow of fresh, warm water into the Gulf of Mexico can have adverse environmental and even climactic effects. It will change the amount of nutrients and the temperature of the water near the mouth of the river, affecting the marine life that thrives there. A change in water temperature can also affect local ocean currents and potentially even rainfall if the change is severe enough.

9. It Would Damage the Colorado River Watershed

Just like the Mississippi system, the Colorado River basin would face potential ecological disaster. The imported water would carry contaminants from Midwestern industry, fertilizers, and pesticides, as well as the thousands of cargo ships, barges, and pleasure craft that ply the waters of the Mississippi. The nutrient levels and types of microorganisms could differ significantly from what is indigenous to the Colorado River system and have a detrimental effect on indigenous species in the west.

10. It Might Spread Invasive Species

There’s a strong possibility that over the years, this pipeline would be a source of infestation by invasive species crossing over from one half of the country to the other, which could never happen if people did not artificially connect these divided river systems. The Mississippi already has numerous invasive species, one of the most pernicious being the Asian carp. It’s an aggressive, bony species with no commercial value that creates a hazard for people swimming or boating on the river and displaces useful indigenous species.

A huge amount of research and investment has gone into trying to prevent them from transiting from the Mississippi into the Great Lakes via the canal system between them. That effort would need to be duplicated to protect the Colorado River system as well. Moreover, species that are indigenous to the Mississippi River system could become invasive if accidentally introduced out west. The water could be filtered and sterilized, but this would add exponentially to the annual expense of the system.

11. It Would Encourage More of the Same

More people live in the west than the environment can sustain. The natural ecosystem in much of the west is arid or even desert. The indigenous plants and animals have adapted to low rainfall and can bounce back after periods of drought. When too many people crowd into the desert to build cities that consume enormous amounts of water and energy (Las Vegas, anyone?) the environment can’t keep up.

Finding new ways to provide water from other regions is not sustainable, and it encourages people to move to these unsuitable areas. Rather than making it easier for people to continue living in the west, it may be best to let nature take its course, allowing costs to rise naturally. This would encourage migration to parts of the country where water is not so scarce and expensive. If this approach is taken, however, provisions need to be made to help people who cannot afford to relocate.

What Could We Do Instead?

These huge, expensive, mega-engineering solutions may ultimately not be as effective as some much simpler things we could start doing immediately.

Xeriscaping

It’s a cultural practice to have a vibrantly green, manicured lawn. On a hot summer day, though, a traditional suburban lawn can easily soak up 100 gallons of water per 1,000 square feet, and each mature tree on the property can drink 15 gallons of water an hour. An alternative is “xeriscaping,” in which lawns are ripped out and replaced with sand, pebbles, ornamental rock features, and indigenous plants with low water requirements. It’s low maintenance and it saves tons of water.

Pools: Asset or Liability?

In hot and sunny climates, having a private pool at your home can feel like a necessity. But it is a luxury. One that takes 18-20,000 gallons of water to fill and has to be continually topped off because of evaporation. How many busy families have pools they don’t use often? If the costs of water are passed on to consumers, pools in the area may become less of an asset in selling homes.

Arizona: A Conservation Success Story

One of the affected states in the region is itself a success story in water conservation. Since the 1950s, Arizona’s population has grown from about one million people to almost seven million. Yet by 2017, the state was actually using less water because they simply learned how to be less wasteful and stretch this precious resource.

The Role of New Technology

All of this is not to say that interventions in the environment will never be a part of an overall strategy to divert water to where it’s most needed. It does suggest, though, that we might focus our technical efforts on solutions that would decisively solve the problem rather than finding ways to transfer one region’s limited resources to another. Desalinization of seawater is one example of a technology that could potentially provide unlimited water to any coastal region that needs it. Processed seawater is an important source of fresh water for households, agriculture, and industry in Persian Gulf countries. The billions we would spend on a water pipeline might be better spent researching ways to make desalinization more cost-effective.

Sustainable energy sources such as solar or even fusion power are other areas worthy of massive research, as they could solve not only current energy needs but could make energy low-cost enough that water could be pumped from the ocean into the deep interior of the continent. Cheap energy could also make it possible to filter and sterilize any water transported so that it does not contaminate the environment with chemicals or invasive species. Whatever the ultimate solution, it’s likely to include an array of efforts, including conservation, cultural change, new social policies, and new technologies.

The photo featured at the top of this post is © John Wreford/Shutterstock.com