Omaha, NE – The U.S. Army Corps of Engineers announced that it will extend the public comment period for the Snake Creek Interim Risk Reduction Measures Draft Environmental Assessment to August 20, 2018.
The draft EA may be downloaded at http://www.nwo.usace.army.mil/Missions/Civil-Works/Planning/Project-Reports/. Comments on the report can be emailed to cenwo-planning@usace.army.mil or mailed to: U.S. Army Corps of Engineers, Omaha District, CENWO-PMA-C, ATTN: Amee Rief, 1616 Capitol Avenue, Omaha, NE 68102-4901. Comments must be postmarked or received by August 20, 2018.
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. 18-057