Upper Big Nemaha L-15 is a local government-owned earth dam located in Lancaster, Nebraska, along the TR-MID BR Big Nemaha River. Built in 1974 by the USDA NRCS, this dam stands at a height of 27 feet and has a storage capacity of 85 acre-feet. Its primary purpose is flood risk reduction, and it serves as a vital structure in the area's water resource management system.

Managed by the NE DNR, Upper Big Nemaha L-15 is regulated, permitted, inspected, and enforced by state agencies to ensure its structural integrity and functionality. With a low hazard potential and a satisfactory condition assessment, this dam provides essential protection against flooding events for the surrounding community. Its location, design, and construction make it a key component in the overall water resource infrastructure of the region.

For water resource and climate enthusiasts, Upper Big Nemaha L-15 represents a successful collaboration between local government, federal agencies, and state regulators to address flood risk and enhance water management capabilities in Nebraska. Its presence underscores the importance of proactive dam management in ensuring the safety and resilience of communities in the face of changing climate patterns and increasing water-related challenges.