WEST CONSULTANTS, INC.
Lewis & Clark Lake Headwaters Aggradation Evaluation. The closure of Gavins Point Dam on the Missouri River at river mile 811 (RM 811) occurred in 1955 to form Lewis and Clark Lake. Significant delta deposits have formed in the headwaters of Lewis and Clark Lake. Engineering analysis is required to perform an evaluation of the impact of aggradation on water levels. Analysis will be performed for the pre-dam condition, the current with dam condition, and a future with dam condition to define aggradation impacted areas. The purpose of the analysis is to provide a basis for future operational decisions and the evaluation of real estate claims related to aggradation and rising ground and surface water stages. The analysis will focus on the Missouri River, Niobrara River, Ponca Creek, Bazile Creek, and Verdigre Creek.