Missouri River Water Management News

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Construction project begins below Gavins Point Dam

U.S. Army Corps of Engineers
Published March 26, 2021


YANKTON, S.D. – A large construction contract has begun in the area below Gavins Point Dam along Lake Yankton. The project is to connect relief wells, which are at the bottom, or “toe” of the dam, that are designed to relieve excess water pressure on the earthen structure. There are 75 relief wells and numerous discharges into Lake Yankton. Of those 75 relief wells, 31 will be connected into three main discharges. This will allow for a more controlled discharge. Once the main discharges are installed, the ground will be backfilled with dirt to cover the discharge pipes and prevent any erosion.

During the construction there will be an increase in truck traffic to the area. This will mostly be Monday – Friday but may happen on a limited basis on Saturdays. Trucks will be turning frequently on and off of Toe Road into grassy areas and will likely take up both lanes of the road. Please slow down around the construction area and give the trucks plenty of room. Do not try to pass the trucks as they may turn abruptly. Your patience is appreciated.

Last fall, in preparation, the water level in Lake Yankton was lowered by 1.15 feet. This lower water level has exposed more of the concrete on the boat ramps at the Cottonwood Day Use and the Training Dike. Boaters will need to use extra caution when launching into Lake Yankton as the exposed concrete will end abruptly. Boaters should evaluate the ramps and determine if the level is safe for their boat. These lower lake levels will be in effect for the duration of the project, which is scheduled for completion in late summer or early fall.

Karla Zeutenhorst

Release no. 21-023