Middle Big Nemaha 18 is a locally owned earth dam located in Tecumseh, Nebraska, along Brewers Branch. Designed by USDA NRCS and completed in 2003, this dam serves primarily for flood risk reduction, with a height of 50 feet and a storage capacity of 1114 acre-feet. The dam stands at a structural height of 56 feet and spans 844 feet in length, encompassing a surface area of 18 acres and draining a watershed area of 3.3 square miles.

Managed by the Nebraska Department of Natural Resources, Middle Big Nemaha 18 is regulated, inspected, and enforced by state agencies to ensure its safety and functionality. The dam's hazard potential is considered significant, although its condition was assessed as satisfactory as of April 2019. With a maximum discharge capacity of 4334 cubic feet per second, this dam plays a critical role in mitigating flood risks in the region, safeguarding nearby communities and infrastructure from potential water-related disasters.

Enthusiasts of water resources and climate will appreciate the strategic importance of Middle Big Nemaha 18 in protecting the Johnson County area from flooding events. As a key infrastructure for flood risk reduction, this earth dam showcases the collaborative efforts between local government authorities, USDA NRCS, and state regulatory agencies to safeguard the community's well-being and resilience against natural disasters. The dam's satisfactory condition assessment and regular inspections underscore its vital role in water resource management and climate adaptation efforts in Nebraska.