Martins Creek Ses Ash Basin No 4 is a privately owned earth dam located in Lower Mount Bethel Township, Pennsylvania. Completed in 1989, this dam stands at a height of 43 feet and has a length of 5740 feet, providing a storage capacity of 325 acre-feet for the TR Oughoughton Creek. The dam serves a primary purpose other than flood control or water supply and is regulated by the Pennsylvania Department of Environmental Protection.

With a drainage area of 0.06 square miles, Martins Creek Ses Ash Basin No 4 poses a significant hazard potential and has been assessed to be in fair condition as of the last inspection in August 2020. The dam has undergone modifications in 2005 to enhance its structural integrity. Despite being privately owned, the dam falls under state jurisdiction with permitting, inspection, and enforcement responsibilities handled by the Pennsylvania Department of Environmental Protection.

For water resource and climate enthusiasts, Martins Creek Ses Ash Basin No 4 provides an intriguing case study of a privately owned dam in Pennsylvania that plays a crucial role in managing water resources and mitigating flood risks. Its location in Northampton County and association with TR Oughoughton Creek highlight the importance of monitoring and maintaining such structures to ensure the safety and sustainability of water systems in the region.