Black Brook is a gravity dam located in Polk, Wisconsin, completed in 1917 for hydroelectric power generation. Managed by a public utility, the dam serves multiple purposes including fish and wildlife pond creation, recreation, and hydroelectricity production. The structure has a height of 25 feet and a length of 270 feet, with a storage capacity of 1400 acre-feet and a drainage area of 162 square miles.

The dam's controlled spillway features a width of 62 feet, and it is equipped with three Tainter gates. Despite its low hazard potential, the risk assessment for Black Brook indicates a very high risk level (1). The Federal Energy Regulatory Commission oversees the dam's operations and inspections, ensuring compliance with safety regulations. With its scenic location on the Apple River, the dam offers opportunities for outdoor recreation and wildlife habitat conservation, making it a valuable resource for water and climate enthusiasts to explore and appreciate.