Barnard is updating the Pipestem Dam in North Dakota, armoring the high-hazard potential dam’s spillway against erosion and ensuring it can accommodate emergency flows from large outflow events.

Located approximately 4 miles from Jamestown, North Dakota, the Pipestem Dam has been identified by the United States Army Corps of Engineers (USACE) as a high-hazard dam due to an ungated earthen emergency spillway channel against the right abutment of the dam. While the emergency spillway has never been used, the reservoir elevations have recently come close to cresting the spillway during spring snow melt, and dam safety assessments have indicated erosion and head cutting of the emergency spillway as a potential failure mode. To address this, Barnard is modifying the existing 3,100-ft.-long, 1,500-ft.-wide structure, armoring the spillway against erosion and ensuring it can accommodate potential emergency flows from large outflow events. This work includes modifying the existing spillway channel, as well as constructing a reinforced concrete labyrinth weir, a roller-compacted concrete (RCC) terminal structure, and training dikes on each side of the channel. Additionally, the work includes excavation of the existing spillway channel.