Jan. 2003: Sediment Threatens Reservoirs
By Howard Paul, executive director of MSAC
In the last newsletter, we discussed in general terms some of the problems that
have been caused by sedimentation in the Missouri River main stem reservoirs.
In this issue, we will discuss the history of these reservoirs. The source for
this history is “The Final Report to Governor George Mickelson” by the Missouri
River Cost Recovery Authority. This report, hereinafter referred to as the
Report, was well researched, has an excellent bibliography, and is highly
recommended by MSAC as a source.
Historically, before the reservoirs were constructed, floods on the Missouri River were devastating, causing massive damage with much loss of life. Some of our older readers can remember those floods. This writer, even though we did not live on the Missouri, can remember the newspaper articles, movie news clips and magazine articles on these floods. (For you younger readers, we did not have television in the Dakotas at that time.) As a result of these terrible floods, the Senate, in 1939, authorized the Bureau of Reclamation (BOR) to study the potential of harvesting the power of the Missouri River to provide hydro-electric power and irrigation water. The power idea was not new to the people of the state who had, in 1918, approved a constitutional amendment allowing the state to construct and operate hydroelectric power plants and to go into debt to finance such projects. In 1943, the House Committee on Flood Control authorized the Corps of Engineers (COE) to make a new flood control survey of the Missouri River. The BOR study was directed by Assistant Commissioner W. Glen Sloan. The COE study was lead by Colonel Lewis A. Pick. Hence, the studies consisted of the Pick Plan and the Sloan Plan, which were combined to form what recognize today as the Pick-Sloan Plan. This plan called for five dams on the Missouri in South Dakota and North Dakota, some improvements to Fort Peck Dam in Montana, (constructed in late 1930s), and numerous potential reservoirs on tributaries, irrigation tracts, pumping systems, levees, and wildlife and recreation areas. Most of these additional facilities were never constructed.
The Pick-Sloan Plan was authorized for construction under the Flood Control Act of 1944. Before this act could gain passage a major issue had to be settled. While navigation from Sioux City south was a major benefit in the plan and was supposed to benefit South Dakota through cheap freight rates, South Dakota was concerned that downstream navigation needs would deprive water from upstream uses. While the downstream states wanted adequate water for navigation, they wanted protection from floods even more. A compromise was reached through the O’Mahoney-Milliken Amendment, which stated in effect that upstream consumptive uses, such as irrigation and domestic/industrial water, had explicit preferences over downstream navigation uses. President Franklin Roosevelt signed the Flood Control Act into law in December of 1944. It is interesting that two of the more significant uses, irrigation in the Dakotas, and navigation in downstream states, are no longer a major factor in the current situation. Irrigation in the Dakotas has not been developed to any great extent, and navigation below Sioux City has declined to the point where it is not a significant economic factor.
Construction of the dams began at Fort Randall in 1946, and Big Bend Dam was the last to be completed in 1966. The dams and reservoirs have been successful in providing low cost power, and in achieving remarkable levels of flood control. As previously noted, irrigation has not reached anywhere near the levels projected in the original concept, and navigation is becoming less and less a viable industry of any significance. Both irrigation and navigation remain important to those persons directly involved, but they do not have the impact originally envisioned. However, recreation, such as boating, fishing, hunting and other outdoor activities, not originally considered as a major benefit in the Act, have become a major industry with a major financial impact, especially in North and South Dakota. Unfortunately, recreation is considered as a local or minor regional factor only, and is not given any significant weight in calculating benefits when benefit/cost ratios are used to determine the feasibility of projects to correct the sediment problem.
That is a brief history of the Flood Control Act of 1944, which resulted in construction of the Missouri River main stem dams. The impact of these dams has been great. Both the Dakotas and the downstream states have benefited from the flood control provided, with most of those benefits accruing in the downstream states. Low cost hydroelectric power has benefited six states, with Minnesota receiving the largest share of firm rate power. Recreation has become a major economic benefit for the Dakotas. While irrigation has not reached its anticipated level, some benefits have been enjoyed and the reformulated Garrison Project still has the potential to become a major benefit in North Dakota. But, unless and until we recognize the potential dangers of uncorrected sediment, and until we do something to address this problem and correct it, these benefits will be greatly reduced or even lost in the future. We cannot let that happen!! In upcoming issues we will discuss in greater detail the benefits and their financial impact. Stay tuned, more is coming.