Located in Mills County, Iowa, Mass Dam is a privately owned structure designed by the USDA NRCS and completed in 1959. This earth-type dam stands at a height of 28 feet and spans 307 feet, with a storage capacity of 41 acre-feet. Its primary purpose is for fire protection, stock, or as a small fish pond, serving the local community of Silver City. The dam is state-regulated and falls under the jurisdiction of the Iowa Department of Natural Resources, with permitting, inspection, and enforcement processes in place.

With a low hazard potential and a moderate risk assessment rating, Mass Dam has not been rated for its condition. It features an uncontrolled spillway type and has a drainage area of 0.29 square miles. The dam has not been modified in recent years and has not undergone a condition assessment. While emergency action plans and risk management measures are not specified, the dam's risk level is considered moderate. Although it is not owned or funded by federal agencies, it has received design support from the Natural Resources Conservation Service.

Despite its relatively small size, Mass Dam plays a crucial role in local water resource management and provides essential services to the community. With its strategic location on the TR-Silver Creek, the dam contributes to fire protection, livestock watering, and recreational fishing opportunities. As climate change continues to impact water resources, structures like Mass Dam will be increasingly vital for ensuring sustainable water use and conservation in the future.