Lewis Dam, located in Percival, Iowa, is a privately owned recreational structure designed by the NRCS in 2002. Standing at 27 feet tall and spanning 400 feet in length, this stone core dam plays a vital role in managing water resources in the area. With a storage capacity of 35 acre-feet and a maximum discharge of 64 cubic feet per second, Lewis Dam helps regulate the flow of water in the tributary to Horse Creek, providing essential support for the surrounding ecosystem.

The dam, regulated by the Iowa Department of Natural Resources, is classified as having a low hazard potential and a moderate risk level. While the condition assessment is currently not rated, the dam has undergone regular inspections since its completion. With a spillway width of 34 feet and uncontrolled spillway type, Lewis Dam ensures the safe release of excess water during periods of high flow. Despite its primary purpose being recreation, the dam also contributes to flood control and water supply management in the Fremont County area.

As a key feature in the region's water infrastructure, Lewis Dam serves as a reminder of the importance of sound engineering practices in mitigating the impacts of climate change. With its strategic location and design, the dam exemplifies the collaborative efforts between private owners, regulatory agencies, and designers in safeguarding water resources for both recreational and environmental purposes. Its role in water management and risk reduction underscores the significance of investing in sustainable infrastructure for a resilient future.