Turkey Creek Watershed Site 1-1 in Cass, Iowa is a flood risk reduction dam designed by the USDA NRCS and completed in 2006. The earth dam stands at 28 feet high and spans 530 feet, with a storage capacity of 134 acre-feet. Located on TR-Turkey Creek, the dam serves to mitigate flood risks in the area, covering a drainage area of 0.3 square miles and a surface area of 7.8 acres.

Managed by the Iowa DNR, this structure is state-regulated and permitted, with regular inspections and enforcement measures in place. Despite its low hazard potential, the dam's risk assessment is moderate, emphasizing the importance of ongoing risk management practices. Owned by the local government and falling under the jurisdiction of Iowa, Turkey Creek Watershed Site 1-1 is a vital piece of infrastructure in safeguarding the surrounding community from potential flooding events.

With its strategic location in the Turkey Creek watershed and efficient design by the NRCS, this dam plays a crucial role in protecting Lewis and its residents from the impacts of extreme weather events. As climate change continues to pose challenges for water resources, the flood risk reduction structure at Site 1-1 stands as a testament to proactive measures taken to ensure the safety and resilience of the local area.