OMAHA, Neb. — Two public meetings to discuss interim measures to reduce dam safety risks at the Snake Creek embankment, which runs under Highway 83 and impounds Lake Audubon in North Dakota, are scheduled for the week of June 26, 2017.
The meetings will be held at the following times and locations:
Tuesday, June 27 from 6 - 8 p.m.
32 S. Main Street
Garrison, ND 58540
Wednesday, June 28 from 6 - 8 p.m.
Ramkota Hotel and Conference Center
800 S. Third Street
Bismarck, ND 58504
The public meetings will include a presentation, starting around 6:30 p.m. each evening, and an open house to provide the public an opportunity to ask questions about interim measures being evaluated to reduce dam safety risks at the embankment, including updating the current Lake Audubon Water Control Plan with a provisional operating restriction to manage lake level differences between Lake Sakakawea and Lake Audubon during drought conditions.
Background: Snake Creek embankment, constructed in 1954, is located eight miles northeast of Riverdale, North Dakota and impounds Lake Audubon, which is a sub-impoundment of Lake Sakakawea. As a result of the prolonged period of drought from 2000-2009, USACE conducted a re-evaluation of the Snake Creek embankment underseepage design which identified a dam safety concern due to high pressures in the dam’s foundation during large elevation differences between Lake Sakakawea and Lake Audubon.
To date, USACE has installed additional dam safety instrumentation to relieve foundation pressures and increase underseepage monitoring capabilities; however, the most effective interim risk reduction measure is to implement a provisional operating restriction to manage lake level differences between Lake Sakakawea and Lake Audubon during drought conditions. Implementing an operating restriction would require an update to the Lake Audubon Water Control Plan, which currently does not include guidance when the Lake Audubon pool elevation is higher than Lake Sakakawea.
Release no. 17-056