Minnesota Dam Risks Failure During Wave of Intense US Weather

A dam holding back swollen flood waters in Minnesota was at risk of failure Monday as intense weather buffeted much of the US.

The Blue Earth River has cut around the west side of the Rapidan Dam, local officials warned in a Facebook post. “The dam is in imminent failure condition,” Blue Earth County posted Monday morning. A later post said the dam, southwest of Minneapolis, is still intact and no evacuation orders have been issued.

The US has been beset by severe weather this week, with a heat wave settling over much of the East Coast, thunderstorms striking the center of the continent and flood watches blanketing the upper Midwest. The National Weather Service reported widespread river flooding across parts of Minnesota and Wisconsin, with some areas over the last 10 days receiving twice or three times the normal amount of rainfall for the entire month of June. Governors in Minnesota, Iowa and South Dakota all declared emergencies to support flood response.

The weather has posed a challenge for electric utilities, as power demand soars in the heat and storms knock out power lines. The same flooding threatening the dam, outside rural Mankato, Minnesota, washed away a nearby electric substation serving about 600 customers early Monday, a representative of power company Xcel Energy Inc. said in an email.

The dam, owned by the county and built more than a century ago, used to supply hydroelectric power until it was damaged by floods in 2019 and 2020. A 2021 study found it was in such poor condition that it needed to be repaired or removed.