There was a full house at the recent Missouri Sedimentation Action Coalition (MSAC) annual meeting in Yankton and a large number who attended virtually to hear from the MSAC leadership and the U.S. Army Corps of Engineers on the status and future of the sedimentation on the Missouri River. This year’s meeting did focus on Lewis and Clark Lake and upper reaches. The corps is completing the Phase Two portion of the Sediment Management Plan (SMP) project conducted under Section 22 of the Water Resources Development Act of 1974, Planning Assistance to States.
This phase has taken nearly three years of information collection, research, and collaboration. In the coming weeks the draft of the final report will be sent to MSAC for review and comment. The presentation preview of this draft at the Annual Meeting was very thorough and encompassed methods and economic factors needed to move onto the next phase, which will select two novel methods to move excess sedimentation out of the reservoir.
Once identified, MSAC will work toward the goal of a feasibility study for at least one of these methods in order to determine effectiveness and economic cost of scaling the method to full scale and using in the long term to achieve an equilibrium and extend the current projected lifespan of the reservoir and power generation of Gavins Point Dam.
Those in attendance were part of an honest and needed conversation on the economic estimates being used to determine the viability of undertaking this project. MSAC was fortunate to have a diverse group in attendance for this conversation. The audience included staff members for all six Nebraska and South Dakota congressional offices whose districts include the lake; parks, natural resources, and tourism representatives for both states; and other government, commercial, and private organizations with equities in the sedimentation issue of the upper Missouri River.
While the economic leg of the stool that is the sedimentation issue has always been important, to achieve the goal of extending the life of the reservoir, MSAC needs to dig much deeper into this aspect.
Phase Two has provided engineering options along with an increase in the scientific knowledge of this stretch of the Missouri River. Going forward there will be a greater focus on the economic benefits and impacts of continuing on the current trajectory of doing nothing versus maturing a method or methods that in the coming years will preserve the life of the reservoir, dam, and upper reaches for generations to come.