Greenwood Lake Dam, located in West Milford Township, New Jersey, is a concrete gravity dam on the Wanaque River with a primary purpose of recreation. Completed in 1928, the dam stands at a height of 17 feet and stretches 270 feet in length, providing a storage capacity of 13,269 acre-feet and covering a surface area of 1,733 acres. The dam is owned and regulated by the state of New Jersey, specifically by the New Jersey Department of Environmental Protection (NJDEP), ensuring that it undergoes regular inspections and enforcement measures to maintain its fair condition.

Despite its fair condition, Greenwood Lake Dam has a high hazard potential, prompting a biennial inspection frequency to assess its safety and functionality. The dam's emergency action plan (EAP) was last revised in July 2018, with no recent updates on its compliance with guidelines or the preparation of inundation maps. While there are no outlet gates or associated structures linked to the dam, its proximity to residential areas and the risk of inundation highlights the importance of ongoing risk management measures and a thorough assessment of potential hazards to ensure the safety of the surrounding communities and water resources.