PIKE RIVER FLOWAGE— The Department of Natural Resources has given the green light for a repair to the Pike River dam that could be in place yet this month. That’s according to Jason Boyle, the DNR’s dam safety engineer.
The repair, to be undertaken by the Nordic Group at a cost of $24,500, is designed to eliminate leakage around the dam’s former penstock, which has contributed to declining water levels on the Pike River Flowage, the artificial lake located just upstream of the dam.
The ongoing drought in the region had eliminated much of the water in the flowage earlier this year.The water level has remained well below normal for late fall, although it has recovered somewhat since late summer, at the height of the drought.
Even at the lowest level, back in August, a considerable amount of water continued to pour out of the former penstock in the dam, which threatened to all but drain the 214-acre flowage.
Boyle said gaps in stop logs that are supposed to prevent leakage through the penstock appeared to be allowing the outflow. One resident of the flowage, who is also a University of Minnesota physicist, had calculated in August that the flowage would be completely drained by October without a break in the drought or repairs to the dam to halt the leakage. More seasonable rains in September helped the water level recover somewhat over the fall, although it still hasn’t returned to normal levels.
The penstock is a large hole near the base of the dam, which was designed to house a turbine to generate electricity. The dam was built 110 years ago by the city of Tower to provide a source of power, but the water flow proved insufficient to provide a reliable source of energy.
While the city quickly abandoned the dam, the artificial lake it created just upstream has become populated over the years with more than a dozen homes and cabins, a natural constituency for maintaining the aging dam.
According to Boyle, he hopes to have the contractor install a metal plate over the penstock on the upstream side of the dam, in order to stem the current leakage.
The repair won’t solve all of the dam’s many issues. A maintenance analysis on the structure several years ago put the price tag for a long-term repair of the structure at several million dollars.