NEWS RELEASE – For Immediate Release June 29, 2018
MSAC invites public to Lewis & Clark Lake Stakeholder Workshop to be facilitated by BYU sedimentation researcher
(Yankton, SD) Stakeholders concerned about the future of Lewis and Clark Lake are encouraged to participate in a workshop scheduled for Friday, July 20 in Yankton at the NFAA Easton Yankton Archery Center, 800 Archery Lane. The session, organized by the Missouri Sedimentation Action Coalition, begins at 9:30 a.m. and will conclude at approximately 12:30 p.m. The primary goal of this workshop is to identify stakeholders to partner in submitting a letter of request to the US Army Corps of Engineers to develop a sediment management plan for Lewis and Clark Lake.

The general public is invited to the workshop. Section 1179(a) of the Water Resources Development Act of 2016 calls for the US Army Corps of Engineers to carry out a pilot program for the development and implementation of sediment management plans for reservoirs of the Upper Missouri River Basin above Sioux City. Under Section 1179(a), potential stakeholders requesting the sediment management plan might be units of government such as state, county and city governments along with tribes and other nonprofit organizations. The study costs to develop a sediment management plan would be shared at a 50 percent federal and 50 percent non-federal or local sponsor(s) expense.


Aug. 1, 2016 – Rollin Hotchkiss at MSAC Meeting in Yankton

MSAC has requested Rollin Hotchkiss, professor of civil and environmental engineering at Brigham Young University, to facilitate the July 20th meeting. Hotchkiss is familiar with Lewis and Clark Lake along with other sedimentation problems around the globe. Hotchkiss has authored more than 150 papers and reports dealing with topics such as determining peak flows in watersheds and turbulence in natural channels and culverts.

With Matthew W. George and Ray Huffaker, Hotchkiss recently wrote a paper entitled “Reservoir Sustainability and Sediment Management.” It was published in the Journal of Water Resources and Planning Management.

The writers point out that passing sediment downstream was not considered at the time of dam construction decades ago. Planning was very shortsighted, particularly with the use of a cost benefit analysis that considered an economic life of projects at 50 to 100 years. At Gavins Point Dam/Lewis and Clark Lake, damages due to lack of sediment management account for 70 percent of the actual construction costs and would likely exceed construction costs if all damage information was available, the writers reported.

Hotchkiss also co-authored “Conversion of a Missouri River Dam and Reservoir to a Sustainable System: Sediment Management” with University of South Dakota researchers Howard E. Coker and Dennis A. Johnson in 2008. The article was published in the Journal of the American Water Resources Association.

In August of 2016, Hotchkiss spoke to reservoir sustainability in particular Lewis and Clark Lake at a public meeting in Yankton hosted by MSAC. Finding the keys to sustain a reservoir like Lewis and Clark Lake not only involves engineering but also an economic framework to put solutions into action.

Those attending the meeting were reminded of the magnitude of this issue that is creeping into their backyards, and their children’s backyards of the Yankton area. Or in places like Niobrara or Springfield — sedimentation has made its presence known for many years.

“The sediment delta – it’s on its way. Gavins Point and its sedimentation issues are the worst in the United States. Congratulations. You got the poster child for this issue in the U.S.,” he said August 1, 2016.

According to MSAC, a sediment management plan could lay the groundwork for the action needed to sustain Lewis and Clark Lake along with providing at outline for short term relief. Section 1179(a) calls for providing opportunities for project beneficiaries and other stakeholders to participate in sediment management decisions.

“This is an excellent opportunity to think about the reservoir and its future sustainability in the big picture. A plan is needed to approach these complex sedimentation problems. This isn’t just another study. It’s a plan for action. We are all well aware of the tremendous amount of time and resources invested in studying sedimentation at Lewis and Clark Lake, which makes the attainability of a sediment management plan more feasible federally and locally,” said Sandy Stockholm, MSAC executive director.

Topics of the July 20th workshop include:

  • What is Section 1179(a) of the Water Resources Development Act (WRDA) 2016?
  • What is the timeline for progression of sedimentation at L&C Lake?
  • What is a sediment management plan? What does sedimentation management look like around the U.S. and globe?
  • What can be done at Lewis and Clark Lake?
  • How will it be implemented?Regional researchers and others will be scheduled to present information. The goal of the workshop is to identify stakeholders who will investigate becoming partners in requesting a sediment management plan under Section 1179a. The stakeholders would agree to contribute 50 percent of the study expense. Another goal is to set a date for a sediment management plan request letter to be submitted to the US Army Corps of Engineers.

    MSAC encourages people to attend for the full session, but attendees can arrive late or leave early. Participation and cooperation is vital. MSAC is a 501c3 non-profit organization funded with membership contributions from local and county governments, individuals, water districts, businesses and organizations. For planning purposes, MSAC encourages interested individuals to call 605-661-1594 or register at to attend the July 20th workshop.

    Registration Link