Blacksville #1 Freshwater Imp is a private dam located in Wayne Township, Greene County, Pennsylvania. Completed in 1974, the earth dam stands at a height of 20 feet and has a length of 1655 feet. The dam's primary purpose is for recreation, with a storage capacity of 338 acre-feet and a surface area of 24 acres.

The dam is regulated by the Pennsylvania Department of Environmental Protection and undergoes regular inspections, with the last one conducted in September 2017. It is classified as having a significant hazard potential, but its condition assessment is satisfactory. Despite its age, the dam continues to serve its intended purpose effectively, providing recreational opportunities for the surrounding community.

Water resource and climate enthusiasts will find Blacksville #1 Freshwater Imp to be an intriguing structure within the TR Dunkard Creek watershed. As a vital part of the local ecosystem, it's important to monitor and maintain the dam to ensure its continued safety and functionality for both recreational and environmental purposes.