Lewis and Clark: Water Use Today


The six mainstem dams and power plants of the Pick-Sloan Missouri Basin Program operated by the Army Corps of Engineers have a total of 36 hydropower units, with a combined capacity of 1,967 megawatts.

Rural scene at sunset, near the Upper Missouri River Basin
Pick-Sloan Missouri River dams and power plants supply electricity to millions of rural people in the Upper Great Plains; Basin Electric Power Cooperative photo

They generate more than 10.2 million megawatt hours of power annually, which is about 9 percent of the energy used in the Mid-Continent Area Power Pool region of Iowa, Minnesota, Nebraska, North Dakota and parts of Illinois, Montana and Wisconsin. In the four Upper Missouri Basin states, the Bureau of Reclamation operates an additional 14 powerplants that generate 2.3 million megawatt hours each year.

When the powerplants were first built, the Bureau of Reclamation had responsibility for marketing the power produced. In 1977 Congress created the Department of Energy and transferred the power marketing function to that agency's Western Area Power Administration. In 1996, the Western Area Power Administration supplied energy to nearly 5 million people in Montana, North Dakota, South Dakota, Nebraska and portions of Minnesota, Iowa, Wyoming, Colorado and Kansas. Power customers include rural electric cooperatives, municipalities, public utility districts, irrigation districts and state agencies. Surplus generation is sold to regional power suppliers, including investor-owned utilities. This power is delivered over approximately 7,400 miles of federal transmission lines and through 90 substations.

The generating facilities required a large Federal investment to complete but, unlike other Federal infrastructure expenditures, hydropower customers have been repaying this investment in hydropower facilities in full and with interest. Since 1968, customers have repaid the government more than $900 million dollars in principal and more than $850 million in interest on the $1.87 billion investment. Customers also underwrite the power operations and maintenance costs of the Federal agencies, which share operating responsibilities for the hydropower production and delivery system. These operating cost payments to the Army Corps of Engineers, the Bureau of Reclamation and the Western Area Power Administration amount to another $1.9 billion.

The hydropower generating capacity that is available from the mainstem dams at any time varies with the water-surface elevations of the reservoirs. For example, as the reservoir elevation falls during long-term droughts, the generation capability of the system decreases.

Power generation at the six mainstem dams generally must also follow the seasonal pattern of water movement through the system. However, adjustments have been made to the extent possible to provide maximum power production during the summer and winter months when demand is high.

Hydropower has some special characteristics that make it an especially valuable power resource, including its renewability, efficient peaking capabilities, rapid rate of unit startup and stopping, and rapid availability for emergencies. The value of the energy produced by hydropower varies from season to season, depending on water conditions and the power demand. The higher the demand, the greater the value of hydropower. Because demand is greatest in the summer and winter, energy produced during these seasons is of greater overall value than energy produced in the spring and fall. This value is greatest when the hydropower units have sufficient water to generate at full capacity levels.

Flood Control

The climate cycles in the region bring periods that are both dry and wet. During the wet cycles, the flood control benefits provided by the Missouri River mainstem dams and the other dams throughout the Upper Missouri region are significant. Estimates are that the dams have suppressed historical flooding in the Missouri Basin states with annual flood control benefits approaching $415 million. This flood control reaches farms, residences and businesses and an approximate worth of $17.6 billion.

Approximately 1.4 million acres of farmland are subject to flooding along the mainstem Missouri River. Increased flood control has opened the door to more development in the floodplain. Rich agricultural lands are sustained, fueled with irrigation opportunities. Private residential areas and businesses continue to spring up along valuable riverfront property. However, development along the river creates a tug-of-war between development interests and environmental groups that oppose continued encroachment on the river.

Existing and new development within the floodplain is regulated by local governmental entities using the minimum National Flood Insurance Program standards.

Rural, Municipal and Industrial Water

The Missouri River and its mainstem dams and lakes are a source of water for municipal water supply, irrigation, cooling water, and commercial, industrial and domestic uses. Water supply benefits throughout the Missouri River basin are more than $541.6 million annually.

The growth and health of the people, their farms and their communities are affected by the availability of clean water. Along the mainstem reservoir system, there are approximately 1,600 water intakes of widely varying size. This includes water supply for more than 200 federal and non-federal rural water systems that have been constructed in Montana, North Dakota, South Dakota and Wyoming to deliver a reliable and dependable water supply to areas of need. While these rural water systems bring quality water to small communities and rural residences, many areas not yet served by rural water systems still suffer from poor quality water and inadequate quantity.

Water quality in the mainstem reservoir system of the Missouri River Basin is generally good, with only minor or suspected problems. These problems are due to many factors including diffuse contaminants; agricultural practices; mining, coal and oil development; sewage treatment problems, and sediment and nutrient inputs into the lakes.


In the Upper Missouri River states of Montana, North Dakota, South Dakota and Wyoming, two million acres of land are irrigated. Irrigated crops include alfalfa, wheat, hay, barley, oats, sugar beets, potatoes, corn and cherries. Irrigation of high-value crops provides a major opportunity for economic stability and increased farm income.

The vision for irrigation development has not been met. The original Pick Sloan Missouri River Plan called for irrigating 5.4 million acres, and it was downsized to 3.8 million in 1958 and 2.9 million in 1986. But an interest in irrigation has continued, especially for value-added agricultural opportunities. Irrigation is vital to many of these opportunities.

The region has land, water, power and labor in plentiful supply and reasonably priced. Irrigation of high value crops provides a major opportunity for economic stability and increased farm income and interest in high value crops have increased their development in recent years.


Recreation activities such as fishing, boating, camping, hunting, sightseeing and wildlife watching produce economic benefits for local communities by increasing jobs, property values and local tax revenue. More than 10 million people annually recreate on the Missouri River from Three Forks, Montana, to St. Louis, Missouri. This generates close to $87 million in annual benefits, according to the U.S. Army Corps of Engineers. More than 70 percent of these 10 million people recreate in the upper basin reservoirs and river reaches.

The variety of recreational opportunities on the Missouri River includes water-based activities like boating, boating-related activities and swimming. Sport fishing is enjoyed along the entire river, and the wetlands along the river provide waterfowl and wildlife habitat, and draw waterfowl and big game hunters.

Sightseers come to enjoy the beauty of the lakes and river reaches. Camping facilities, especially along the lakes of the mainstem reservoir system, vary from fully developed to primitive. More than 80,000 acres of recreational lands are located along nearly 6,000 miles of lake shoreline.

Water levels are a key factor in use of the lakes and river. Low lake levels make some boat ramps unusable, and certain kinds of hunting and fishing depend on lake levels and stream flows. This is especially true in the Upper Missouri reservoir lakes of Fort Peck, Lake Sakakawea and Lake Oahe, whose levels are affected the greatest during times of drought.


Much of the Missouri River has changed from being "The Big Muddy" to being a vast, blue water reservoir system. Its water quality is generally good, and can fully support a variety of human water supply needs.

Studies are underway to determine potential problems associated with the application of agricultural pesticides, increased concentration of heavy metals in soils, water, plant and animal life, and industrial pollution. Water quality monitoring will aid in understanding the role of flood plain wetlands in absorbing and processing nitrogen, phosphorus and contaminants in runoff waters.

The Army Corps of Engineers regulates the discharge of rock, sand or dirt in the waters of the United States through Section 404 of the Clean Water Act. Permits must be authorized for Section 404 activities including roadfills, dams and dikes and other protection devices. Permits can be denied if conservation, economics, environmental concerns, fish and wildlife values, historic values, water supply and water quality are considered to be significantly impacted.

A contemporary concern is the linkage between bank stabilization and development and how they may affect aquatic life and the food chain into the future.

In direct connection with riverbed and bank erosion, deltas are forming at a considerable rate. Soil from the Missouri River is being deposited at the headwaters of reservoirs, where the water velocity is low. This silt load moved along with ease before the dams were built. But Lake Sakakawea's delta near Williston has increased from five to 11 feet between 1956 and 1988. Oahe delta sediment has accumulated at a rate of 14,665 acre-feet per year, raising the lake bed elevation from two to eight feet.

As these deltas grow, storage capacities of Lake Oahe and Lake Sakakawea diminish and pose serious threats to adjacent land. Higher water tables waterlog agricultural lands and deltas can cause or aggravate ice jam formations and cause subsequent flooding.

Fish and Wildlife

The Missouri River is a dynamic system that creates and maintains important forest, grassland and wetland habitat for a wide diversity of wildlife including at least 60 species of mammals, 300 species of birds, 50 species of reptiles and amphibians. Of these, six bird and two bat species occurring in the River Valley are federally listed as threatened or endangered.

The diversity and abundance of wildlife reflect the mix of habitat classes in the Missouri River basin: riverine; lakes and ponds; emergent, scrub-shrub, and forested wetlands; riparian forests; grasslands, and croplands. The combination of open water, wetlands and riparian vegetation is particularly important for the large number of waterfowl that stop along the Missouri River during spring and fall migration.

Over 150 native and introduced fish species live in the Missouri River. Its dams have lowered turbidity and water temperatures, causing the demise of many native fish species, including paddlefish and sturgeon. The clear, cool water, however, has been advantageous for other species such as walleye, salmon and smallmouth bass. Recreational fishing, especially on Lake Sakakawea and Lake Oahe, has developed beyond all expectations, hosting some of the best walleye fishing in North America.

More than 5,000 hours of fishing per river mile occur each year on the Missouri River today, with a harvest of more than two tons of walleye per river mile in certain areas. The Missouri and Yellowstone Rivers above Williston, North Dakota, still function to a large degree as wild rivers, and are home to some of the largest populations of pallid sturgeon and paddlefish found anywhere.

The loss of habitat to reservoirs and Missouri River dam operation have posed a threat to several species that depend on high spring flows to recharge and inundate backwaters, wetlands and riparian habitat. Cattle grazing and lack of flood-nourished soil has contributed to the decline of cottonwood trees in the Dakotas and Montana, lessening nesting and roosting habitat for the bald eagle and other raptors. The pallid sturgeon once thrived in a large, turbid river environment, and now they are endangered.

Under the Endangered Species Act, the U.S. Fish and Wildlife Service and the Corps of Engineers are working to recover these species, along with the endangered least tern and threatened piping plover. These birds rely on lower river levels for nesting and sandbar vegetation.

Last Updated: 6/24/20