Thorston B-2a is a local government-owned earth dam in Saunders, Nebraska, designed by the USDA NRCS and regulated by the NE DNR. Completed in 1954, this dam serves the primary purpose of flood risk reduction along the TR-Wahoo Creek. With a height of 23 feet and a length of 900 feet, Thorston B-2a has a storage capacity of 380 acre-feet and a drainage area of 1.42 square miles.

Located in Ithaca, Nebraska, this dam has a low hazard potential and is currently in satisfactory condition, last inspected in May 2016. With a hydraulic height of 21 feet and a structural height of 26 feet, Thorston B-2a plays a crucial role in mitigating flood risks in the region. The dam's design includes a stone core and soil foundation, ensuring its stability and effectiveness in managing water resources and protecting the local community from potential flooding events.

Managed by the Natural Resources Conservation Service, Thorston B-2a is an essential infrastructure in the area, with a normal storage capacity of 18 acre-feet and a maximum discharge of 1,660 cubic feet per second. With its strategic location and key role in flood risk reduction, this dam stands as a testament to the importance of sustainable water resource management and climate resilience in Nebraska.