SPOONER, Wis. — Safety and code compliance concerns with the Little Falls Dam in northwestern Wisconsin have led the Wisconsin Department of Natural Resources to develop a plan for a controlled breach of the dam to allow a drawdown to proceed.
Working with an engineering consulting firm and community groups, DNR developed a plan to lower water levels behind the dam starting in mid-June and concluding in mid-July. Since then, however, repeated rain events have occurred and water levels have not reached desired targets, said Paul Bruggink, northern Fish, Wildlife and Parks Division representative with DNR.
While the previous plans called for a six inch per day drawdown, the repeated rain events have not allowed the water level to reach a point where sediment management, including erosion control, could take place. As a result, DNR has concluded a controlled breach will be the best way to address health and safety concerns arising from the dam’s structural issues as well as sediment management.
In addition to restoring safer and more predictable conditions downstream, the breach strategy will allow natural vegetation to become established prior to the end of the growing season and prevent future erosion, Bruggink said. The breach is not expected to negatively affect the fishery; while there will be immediate changes in local fish populations, populations will quickly stabilize and return to normal in both the lake and Lower Willow River.
DNR intends to initiate the work to breach the dam as soon as a contractor has been identified. The drawdown work is intended to be complete by late fall.