SIOUX FALLS, S.D. (KELO) — It was a dramatic sight Friday morning at Gavins Point Dam west of Yankton, as white-cap waves on Lewis and Clark Lake crashed into the dam, splashing up and over the spillway gates.
The United States Army Corps of Engineers (USACE) said this activity, though dramatic, is not a danger to the dam itself.
“What you’re seeing is simply wind-driven wave action – not water being released by the dam, and not overtopping in the technical sense,” said Andrew Nyström, public affairs officer for the USACE. “Gavins Point Dam is operating safely and as designed. Our infrastructure is built to withstand these types of surface conditions, and we’re constantly monitoring water levels and structural integrity.”
Nyström noted that there have been high-water events in the past that required the USACE to open all the spillways at Gavins Point. “Not taking those actions could lead to structural concerns like uncontrolled releases or potential gate damage,” Nyström said.
The waves on the lake, rising several feet high, as seen in a video sent by a viewer, were driven by winds of around 30 mph, with gusts up to 37 mph.
Nyström says that while these waves seem large, the dam itself is made of both concrete structures and engineered earthen embankments which are routinely inspected.
While the waves do not represent a danger to the dam, the USACE encourages safety for those visiting.
“This includes wearing a life jacket when on the water, keeping a safe distance from the spillway and powerhouse areas, and staying informed through project updates,” said Nyström. “Windy days like today may amplify surface activity, so it’s always important to remain aware of your surroundings when boating, fishing, or walking near the water.”
