Thayer Dam, located in Nelson, Nebraska, is a privately-owned structure designed by the USDA NRCS and regulated by the Nebraska Department of Natural Resources. Completed in 1966, this earth dam serves multiple purposes including fire protection, stock, and small fish pond management. With a height of 17 feet and a length of 350 feet, the dam provides storage for up to 71 acre-feet of water from the TR-Little Blue River.

Despite its low hazard potential and satisfactory condition assessment, Thayer Dam is subject to regular inspections and enforcement by state agencies to ensure its continued safety and functionality. The dam's design includes buttress and stone core types on a soil foundation, with a maximum discharge capacity of 222 cubic feet per second. Its presence contributes to the local water resource management and environmental conservation efforts in the Nuckolls County area.

As a key feature within the Omaha District of the US Army Corps of Engineers, Thayer Dam plays a crucial role in maintaining water levels and supporting various ecological and agricultural activities in the region. Its construction and operation are essential for fire protection, livestock watering, and small-scale fisheries, making it an integral part of the local landscape for both residents and water resource enthusiasts to appreciate and support.