Harnessing the River

In the city’s early years, industries at the Falls of the Big Sioux River used the river’s flow to run machinery. The Queen Bee Mill used water power to produce wheat flour, and the Sioux Falls Light & Power Company hydro-electric plant used it to generate electricity. Both companies needed a large, reliable flow of water, so they significantly altered the river channel and the rock formations of the falls. A dam built above the falls created a mill pond that raised the water level to increase pressure and deliver more power to the turbine, and at the dam’s east end the water was diverted from the river to spin the turbine. The Queen Bee Mill had one turbine and the power plant had three. At the mill, water from the mill pond passed through the mill race to the Gate House, where a wooden gate controlled its flow, then moved through an 8-foot diameter iron flume to the penstock, where pressure forced a large horizontal turbine to spin a vertical drive shaft. Gears then turned the mill’s main drive shaft, and inside the mill, gears, pulleys, and leather belts powered the machinery. After turning the turbine, the water exited through a brick arch into the tail race and returned to the river. The mill ruins, a replica of the mill’s turbine house, and the historic power plant building remain today, and the mill ruins and power plant building are listed on the National Register of Historic Places.

Sioux Falls, South Dakota · United States