Clark Mills (Pa-490) is a local government-owned earth dam located in Perry Township, Mercer, Pennsylvania. Built in 1971 by the USDA NRCS, this dam on Calvin Clark Run serves the primary purpose of flood risk reduction. Standing at a height of 45 feet and with a length of 430 feet, it has a storage capacity of 790 acre-feet and covers a surface area of 4 acres.

This dam is regulated by the Pennsylvania Department of Environmental Protection, with state permitting, inspection, and enforcement in place. Despite being classified as having a high hazard potential, the dam is currently in fair condition, as assessed in the last inspection conducted in September 2020. With a drainage area of 3.29 square miles, Clark Mills plays a crucial role in managing water resources in the region and mitigating flood risks for the local community.

Enthusiasts of water resources and climate will find Clark Mills (Pa-490) to be an intriguing case study in dam infrastructure. With its historical significance, design by the USDA NRCS, and state regulation ensuring its safety and functionality, this dam serves as a vital asset for flood risk reduction in Mercer, Pennsylvania. As efforts continue to maintain and improve its condition, Clark Mills stands as a testament to the importance of effective water resource management in addressing the challenges of a changing climate.