Hartwig is a privately owned dam located in Mount Pleasant Township, Wayne County, Pennsylvania. Constructed in 1988, this earth dam primarily serves the purpose of recreation, with a height of 17 feet and a length of 385 feet. The dam has a storage capacity of 132 acre-feet and covers a surface area of 13 acres, with a drainage area of 0.86 square miles. Despite its low hazard potential, Hartwig is regulated by the Pennsylvania Department of Environmental Protection and undergoes regular inspections to ensure its satisfactory condition.

Situated on the TR Johnson Creek and managed by a private owner, Hartwig is subject to state jurisdiction, regulation, permitting, inspection, and enforcement. The dam is equipped with a spillway, however specific details such as spillway type and width are not provided. The last inspection in July 2018 deemed the dam to be in satisfactory condition, with an inspection frequency of 5 years. While no Emergency Action Plan (EAP) or inundation maps are mentioned, the dam's risk assessment and management measures remain unspecified.

With its tranquil surroundings and recreational purpose, Hartwig acts as a valuable asset for water resource and climate enthusiasts in the region. Although its primary function is for recreational use, the dam's importance lies in its regulation by the Pennsylvania Department of Environmental Protection, ensuring the safety and integrity of the structure for both the community and the environment. As a part of the Philadelphia District of the US Army Corps of Engineers, Hartwig's significance extends beyond its scenic beauty to include essential monitoring and maintenance practices to safeguard its long-term sustainability.