Will South Dakota be ready when other states come for our water?

February 19, 2023 7:00 am
Big Bend Dam on the Missouri River in South Dakota. (Courtesy Army Corps of Engineers)

Big Bend Dam on the Missouri River in South Dakota. (Courtesy Army Corps of Engineers)

The massive volume of reservoirs on the Missouri River is one of the nation’s least-appreciated public resources, but that could change as Western states grow more desperate for water. 

“They’re tapped out, and so logic tells you they have to go to the next plentiful resource, which ultimately is the Missouri River,” said Troy Larson, executive director of the Lewis and Clark Regional Water System based in Tea. 

Largest-capacity reservoirs in the U.S.

  1. Lake Mead (Arizona/Nevada): 28.945 million acre-feet
  2. Lake Powell (Arizona/Utah): 26.215 million acre-feet
  3. Lake Sakakawea (North Dakota): 24.3 million acre-feet
  4. Lake Oahe (South Dakota/North Dakota): 23.5 million acre-feet
  5. Fort Peck Lake (Montana): 19.1 million acre-feet

Larson is one of the South Dakota water leaders starting to discuss the possibility of a Western-state rush for Missouri River water. 

More about that in a minute.

First, let’s consider what Western water officials will discover when they peek over the Rocky Mountains, gaze across the plains, and evaluate the six Missouri River reservoirs. 

Lake Sakakawea in North Dakota, Lake Oahe in South Dakota and North Dakota, and Fort Peck Lake in Montana rank as the nation’s third, fourth and fifth largest reservoirs, respectively. Add in the other three reservoirs – Lake Sharpe, Lake Francis Case and Lewis and Clark Lake, all in South Dakota – and the total system capacity rises to a mind-boggling 24 trillion gallons. 

That doesn’t mean the Missouri River is immune to problems. Droughts and management decisions can reduce water levels, while the competing demands of water pipelines, hydroelectric power generation, flood protection, recreation and downstream barge traffic often collide. All the while, sediment is building up in the reservoirs, creating a slow-moving and expensive problem that so far lacks a solution.

But the fact remains that all the water in the reservoirs lies within three states with a combined population of less than 3 million. In other words, said Larson, “There is far more water going by us in the Missouri River than we will ever use.”

Western water woes

Meanwhile, 40 million people in seven Western states are confronting the possibility of running out of water. They rely on the Colorado River, which is compromised by population growth, agricultural irrigation and drought. 

Six of those states – including our neighbor, Wyoming – recently agreed to a new management framework for the river and its imperiled reservoirs, Lake Mead and Lake Powell (the No. 1 and 2 largest-capacity reservoirs in the nation). But if they don’t convince California to join the agreement, they’ll have to accept water reductions imposed by the federal government.

Those negotiations, however they turn out, are unlikely to fix the long-term problem: too many demands on a single, shrinking source of water. The affected states may have to consider other solutions, which could include importing water from the Missouri River. 

The federal government analyzed that idea in a 2012 study. At a cost of up to $14 billion and with all sorts of technical, environmental, political and land-acquisition challenges standing in the way, Interior Secretary Ken Salazar dismissed pipelines as “impractical and not feasible.”

More recently, the Colorado Conservation Board told me in a written statement, “At this time, the concept of a pipeline from the Missouri River is not part of any discussion or alternatives for addressing Colorado River issues.”

But other states already view the Missouri River as a solution to their water woes. In Kansas, a groundwater management district hauled 6,000 gallons of river water to the southwest part of the state last year to test a proposed aqueduct, as part of an effort to prevent depletion of the Ogallala Aquifer. 

Larson thinks more states will covet the Missouri River, especially as other water options dry up.

“If you don’t have it,” Larson said, “you’ll pay anything to get it.”

‘Only a matter of time’

There’s nothing preventing an out-of-state person or entity from seeking a Missouri River water right in South Dakota. Applications go to a state board that generally approves them if water is available and the application is for a “beneficial” use; however, requests for more than 10,000 acre-feet per year require legislative approval.

Because water rights are ranked by date, rights obtained today are better than those obtained tomorrow. If there’s a dispute or a period of low water, earlier rights-holders get their water first.

What does that mean for South Dakota? Larson and other water leaders say it’s time to inventory the state’s existing water supply, to estimate current and future needs, to obtain water rights for those needs, and to get busy extending and building pipelines – which, as South Dakotans know from experience, can take billions of dollars and decades of planning and construction.

Some of that work is underway. State government, flush with federal stimulus money, awarded $600 million for water and wastewater projects last year. A group of water officials called Water 2040 has formed to coordinate efforts across the state. Several pipeline projects are in the planning stages, including the Dakota Mainstem Regional Water System (focusing on the central and southern portions of eastern South Dakota), the Western Dakota Regional Water System, and Water Investment in Northern South Dakota. And the existing Lewis and Clark Regional Water System continues to grow.

Additionally, legislators are mulling proposals to devote more federal money from a state budget surplus to water development.

All of that work is important, and it must continue. Otherwise, South Dakotans could end up standing in line for their own water when other states come calling.

“We firmly believe it’s only a matter of time,” Larson said.




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Seth Tupper
Seth Tupper

Seth is editor-in-chief of South Dakota Searchlight. He was previously a supervising senior producer for South Dakota Public Broadcasting and a newspaper journalist in Rapid City and Mitchell.