Whitney Ridge, located in Unity Township, Pennsylvania, is a private earth dam constructed in 1899 for recreational purposes along the TR Ninemile Run river. With a height of 18 feet and a length of 500 feet, this structure has a storage capacity of 79 acre-feet and covers a surface area of 6 acres. The dam is regulated by the Pennsylvania Department of Environmental Protection and undergoes regular inspections, with the last one conducted in September 2020.

Despite being classified as having a high hazard potential, Whitney Ridge is currently in fair condition according to the most recent assessment. The dam has a drainage area of 2.2 square miles and a normal storage capacity of 55 acre-feet, making it a significant feature in the local watershed. It underwent hydraulic modifications in 2014 to enhance its performance and safety measures.

Water and climate enthusiasts will find Whitney Ridge an intriguing site for its historical significance and contribution to recreation in the area. With its proximity to Pittsburgh District and alignment with state regulatory guidelines, the dam serves as a valuable asset for both water management and outdoor leisure activities in Westmoreland County, Pennsylvania.