Located in Howard County, Iowa, the Lylah Marsh Dam is a local government-owned structure built in 1960 by designers Wallace, Holland, and Kastler. The dam is situated on the Little Wapsipinicon River, near the city of Elma, and serves primarily for recreational purposes, offering a surface area of 52.5 acres for outdoor activities. With a height of 11 feet and a length of 932 feet, the dam has a storage capacity of 358 acre-feet and a drainage area of 21 square miles.

Although the dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, it is regulated by the Iowa Department of Natural Resources, which oversees permitting, inspections, and enforcement. The structure features an uncontrolled spillway and a soil foundation, making it an earth dam type. Despite not having outlet gates or locks, the dam has a moderate risk assessment of level 3, indicating a need for ongoing risk management measures to ensure its safety and integrity for the surrounding community.

Given its location within the Rock Island District and under the jurisdiction of the Iowa DNR, the Lylah Marsh Dam represents a valuable resource for both water recreation enthusiasts and climate advocates. As efforts continue to maintain and monitor the dam's condition, its role in providing recreational opportunities and water storage for the region remains essential, highlighting the intersection of human infrastructure with natural resources in the context of water resource management and climate resilience.