Summary: 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. The draft EA describes the preferred alternative of 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 to reduce dam safety risks.
Geographic Scope: Lake Sakakawea, Riverdale, ND
Decision/Date: Finding of No Significant Impact/18 March 2019