School Section Lake is located in Sections 16 and 17, Town of Ottawa, Waukesha County. It is a 122-acre impoundment built in 1938 and supported by a 3,000-foot long earthen berm. There is a 22-foot wide concrete outlet structure with wood stop logs (a/k/a “spillway”) to control the lake water level and outflow. Waukesha County owns the earthen berm, spillway and adjacent boat launch.
On January 25, 2018, a 20-foot wide breach was discovered on the earthen berm about 400 feet north of the outlet structure, believed to be started/caused by muskrat burrows. To eliminate flow in the breach area, and prevent total berm failure, all the stop logs were slowly removed in the outlet structure over the next week to draw down the lake level approximately 30 inches. This process was completed on February 1, 2018, and the breach was stabilized. Public access to the lake was closed on January 25 due to dangerous ice conditions. (Note: The stop logs in the spillway and the boat launch were originally scheduled for replacement in fall of 2018 in cooperation with a planned lake drawdown over the following winter to control AIS in the lake.)