Dunmore No 3 is a private earth dam located in Roaring Brook Township, Lackawanna County, Pennsylvania. Completed in 1845, it serves as a vital water supply structure on TR Little Roaring Creek, with a storage capacity of 78 acre-feet and a normal storage level of 55 acre-feet. The dam stands at a height of 14 feet and has a length of 600 feet, covering a drainage area of 0.1 square miles.

Managed by the Pennsylvania Department of Environmental Protection, Dunmore No 3 has been deemed to have a low hazard potential and fair condition assessment. Inspected last on December 29, 2020, the dam is subject to regular assessments every five years to ensure its structural integrity and safety. Despite its age, the dam continues to fulfill its primary purpose of supplying water to the surrounding area, showcasing the lasting impact of historic water resource infrastructure in Pennsylvania.

With its historical significance and ongoing role in water supply management, Dunmore No 3 stands as a testament to the importance of sustainable water resource practices in the face of evolving climate conditions. As climate enthusiasts and water resource advocates continue to monitor and assess the impact of climate change on water infrastructure, structures like Dunmore No 3 serve as essential components in ensuring the resilience and reliability of water systems for future generations.