Summary

The Missouri River reservoir system is a critical national resource that provides a variety of benefits, including navigation, flood control, irrigation, hydropower, municipal and industrial water supply, recreation, and fish and wildlife habitat. The U.S. Army Corps of Engineers (Corps) is responsible for operating the Missouri River system to serve these congressionally authorized purposes. Between 1933 and 1964, the Corps built six dams on the Missouri River to serve the water resource needs within the Missouri River basin. The resulting reservoirs form a series of lakes from Montana to the South Dakota-Nebraska border. The Corps manages the system of dams and reservoirs according to the water control plan presented in its Missouri River Mainstem Reservoir System Master Water Control Manual, which was first published in 1960 and most recently revised in 2006. The master manual provides water control criteria for the reservoir system for a spectrum of anticipated runoff conditions. Annual operating plans based on these criteria provide detailed reservoir regulation for each operating year. Four states, Iowa, Nebraska, Kansas, and Missouri, are adjacent to the Missouri River and are served by barge and other vessel traffic along the river. Two states, Iowa and Missouri, are served by navigation on both the Missouri River and the Mississippi River. Both private companies and the Corps have conducted navigation activities on the Missouri River to and/or from these states. Companies transport numerous commodities, such as fertilizer, which is shipped from a port of origin to a port of destination, or sand and gravel, which some companies mine from the river and then transport to a processing facility on shore. In addition, the Corps conducts river maintenance and habitat recovery projects, which require the shipment of waterway improvement material, such as stone or rock. In this context, Congress asked GAO to determine (1) the annual and total tonnage of commodity shipments for each state served by the Missouri River, and (2) the comparable tonnage of commodity shipments transported on the Mississippi River for states served by both the Missouri and Mississippi rivers.

Of the total commodity tonnage shipped on the Missouri River between 1994 and 2006, 83 percent (100,183,464 tons) originated and/or terminated in the state of Missouri. For the other states served by navigation on the Missouri River, Kansas accounted for 12 percent (14,171,543 tons), Nebraska accounted for 3 percent (3,279,355), and Iowa accounted for 2 percent (2,578,890) of the tonnage transported. Tonnage shipped per year over the 13-year period has ranged between 6.9 million and 9.7 million tons. The majority of the shipments on the Missouri River during this period were of sand and gravel, which accounted for 84 percent (about 91.3 million tons) of the total tonnage shipped. Of this amount, approximately 54 percent of the sand and gravel was transported 1 mile or less, 31 percent between 2 and 9 miles, and 14 percent was transported 10 miles or more. According to Corps officials, the short distance traveled is because private companies often mine sand and gravel directly from the Missouri River and then ship the material short distances to a processing facility on shore. Other commercial products accounted for 14 percent of the total tonnage shipped between 1994 and 2006, including 5.2 million tons in food and farm products, 4 million tons of chemicals, 3 million tons of petroleum, 2.5 million tons of primary manufactured goods, 346,460 tons of crude material, and 14,663 tons of manufactured equipment. Waterway improvement material, with 2.2 million tons, accounted for 2 percent of the total tonnage during this period. For the two states that are served by both the Missouri and Mississippi Rivers, tonnage shipped on the Mississippi River was greater than the tonnage shipped on the Missouri River for comparable products. For example, 2.8 million tons of food and farm material were shipped to and/or from Missouri or Iowa on the Missouri River between 1994 and 2006. In contrast, 189 million tons of food and farm material were shipped to and/or from Missouri or Iowa on the Mississippi River during the same period. Sand and gravel was the exception, with about 89 million tons shipped to and/or from Missouri on the Missouri River, compared to about 70 million tons of sand and gravel that were shipped to and/or from Missouri on the Mississippi River.