Felt Mill, located in Waupaca, Wisconsin, is a privately-owned hydroelectric dam on the Crystal River. Built in 1900, this gravity dam stands at a height of 26 feet and spans 400 feet in length, with a storage capacity of 250 acre-feet. Its primary purpose is to generate hydroelectric power, while also serving recreational activities in the area.

The dam is regulated by the Wisconsin Department of Natural Resources (WIDNR) and undergoes regular inspections to ensure its structural integrity. With a hazard potential rated as high and a condition assessment marked as fair, Felt Mill poses a risk that is considered very high according to a recent risk assessment. Emergency action plans are in place, although their last revision date is listed as 2018.

Located in a picturesque setting along the Crystal River, Felt Mill serves as a key player in water resource management and climate action efforts in the region. Enthusiasts of water resources and climate sustainability will find interest in the history, design, and regulatory aspects of this iconic dam.