An aging dam in Minnesota is in “imminent failure condition” after flooding on the Blue Earth River, officials say. The Blue Earth County Sheriff’s Office said Monday that there had been a breach on the west side of the Rapidan Dam near Mankato, but the main part of the 114-year-old dam is “still intact and there are no current plans for a mass evacuation,” CBS News reports. Water surged around the dam after debris accumulated early Monday, washing away the western bank and several buildings including an electrical substation, reports the Mankato Free Press.

“The dam could fail,” Eric Weller, Blue Earth County emergency management director, said Monday, per the Star Tribune. He said people who would be in danger from a collapse have been warned and many have been evacuated. Officials in North Mankato say a flood emergency has been declared and an earthen levee is being built “out of an abundance of caution.” Officials say that if the entire dam fails, the river will surge around 2 feet, enough for existing flood-control systems to handle. (A rail bridge linking Iowa and South Dakota collapsed Sunday night.)