Upper Little Nemaha 42 is a local government-owned dam located in UNADILLA, Nebraska, along the RUSSELL CREEK. Constructed in 2000 for flood risk reduction, this earth dam stands at 39 feet high and has a storage capacity of 941 acre-feet, with a normal storage of 146 acre-feet. With a low hazard potential and satisfactory condition assessment as of May 2016, the dam is under the regulatory oversight of the Nebraska Department of Natural Resources.

The dam's primary purpose of flood risk reduction serves the surrounding Otoe County community by mitigating the impact of potential flooding events. Its earth core and stone foundation provide structural stability to handle a maximum discharge of 1522 CFS. The dam's location within Congressional District 01, Nebraska, under the oversight of Representative Jeff Fortenberry (R), highlights the importance of water resource management in the region.

Despite having no associated structures, Upper Little Nemaha 42 plays a vital role in protecting the area from potential flooding risks. With regular inspections and enforcement measures in place, the dam ensures the safety and well-being of the local community. Its presence contributes to the overall water resource management efforts in Nebraska, showcasing the importance of climate resilience and preparedness in the face of increasing environmental challenges.