Lower Yellowstone River Irrigation Diversion Weir

under planning

The U.S. Army Corps of Engineers has awarded a $34.8 million firm-fixed-price contract to Ames Construction Inc. to construct a replacement irrigation diversion weir across the Lower Yellowstone River and a fish bypass channel through Joe’s Island, in Glendive. The weir consists of a steel W-pile section foundation with reinforced concrete crest structure capping it, and it will be upstream of an existing wooden weir constructed in 1911-1912, with riprap placed between the weirs. Ninety-four W-pile sections will be driven to a depth of 37 ft. The weir length is 700 ft. The bypass channel will be 2.2 miles long, with a 75-ft bottom width, a 200-ft top width and an 18-ft depth. The channel side slopes will be protected with a layer of riprap on bends, the invert and side slopes protected with cobbles processed from the excavation, and the entrance and exit and two locations within the channel protected with riprap structures. The channel excavation requires an intense dewatering system to be designed by the contractor, and earthen cofferdams at the channel entrance and exit. Construction is expected to be completed by March 2021.