Upper Big Nemaha J-34 is a local government-owned earth dam located in Johnson, Nebraska, designed by USDA NRCS and regulated by the Nebraska Department of Natural Resources. Completed in 1969, this dam stands at a height of 25 feet with a structural height of 30 feet and a length of 580 feet. Its primary purpose includes flood risk reduction, with a normal storage capacity of 13 acre-feet and a maximum discharge of 634 cubic feet per second.

Situated on TR-Hooker Creek, Upper Big Nemaha J-34 plays a crucial role in managing water resources in the area, covering a drainage area of 0.3 square miles. With a low hazard potential and a satisfactory condition assessment as of May 2017, this dam serves as a vital infrastructure for water conservation and flood control in the region. The dam is inspected every 5 years to ensure its continued functionality and safety, further emphasizing its importance in the local water resource management system.

Overall, Upper Big Nemaha J-34 is a key component of the water infrastructure in Johnson, Nebraska, contributing to flood risk reduction and water storage in the area. Managed by local government entities and designed by USDA NRCS, this earth dam provides a critical safeguard against potential flooding events and helps maintain the overall water balance in the region. Its low hazard potential and satisfactory condition assessment underscore its significance in ensuring water resource sustainability and climate resilience for the community.