Upper Big Nemaha 15-D is a local government-owned dam in Lancaster, Nebraska, designed by USDA NRCS and regulated by the Nebraska Department of Natural Resources. Completed in 1974, this Earth-type dam stands at a height of 26 feet and spans 950 feet, serving primarily for flood risk reduction along the TR-MID BR Big Nemaha River. With a normal storage capacity of 155 acre-feet and a maximum discharge of 875 cubic feet per second, this structure plays a crucial role in managing water flow and protecting the surrounding area from potential flood hazards.

The dam's low hazard potential and satisfactory condition assessment indicate its reliability in mitigating flood risks and ensuring community safety. Its last inspection in September 2016 found the structure to be in good working order, with an inspection frequency of every 5 years. The dam's location in Firth, Nebraska, highlights its strategic placement within the watershed, contributing to the overall water resource management efforts in the region. As a key component of the local flood control infrastructure, Upper Big Nemaha 15-D plays a vital role in safeguarding the community against potential water-related challenges.

Overall, Upper Big Nemaha 15-D stands as a testament to effective collaboration between local government agencies, regulatory bodies, and design professionals in ensuring the resilience of water resource infrastructure in Nebraska. Through its design and operation, this dam exemplifies the importance of proactive flood risk reduction measures in the face of changing climate patterns and increasing water-related challenges. Its continued maintenance and adherence to regulatory standards underscore the commitment to safeguarding both the environment and local communities from potential water-related risks in the years to come.