Twin Lakes No 1, located in Westmoreland, Pennsylvania, is a recreational earth dam completed in 1908 with a height of 31 feet and a storage capacity of 470 acre-feet. Managed by the Pennsylvania Department of Environmental Protection, the dam sits on Little Crabtree Creek and serves as a vital water resource for the surrounding community. With a surface area of 33 acres and a drainage area of 1.9 square miles, Twin Lakes No 1 provides not only recreational opportunities but also essential water storage for the area.

Despite its age, Twin Lakes No 1 remains in satisfactory condition according to its most recent inspection in August 2019, with a high hazard potential due to its location. The dam, primarily used for recreation, offers a peaceful escape for visitors while also serving a crucial role in water management and flood control. As a state-regulated structure, it undergoes regular inspections and maintenance to ensure its continued safety and functionality. With its historical significance and environmental impact, Twin Lakes No 1 stands as a testament to the importance of responsibly managing and preserving our water resources in the face of changing climate patterns.