Mason Dam, located in Jasper County, Iowa, was completed in 1963 and is owned by a private entity. The dam, with a height of 22 feet and a length of 526 feet, serves multiple purposes including fire protection and creating a small fish pond. Its primary source agency is the Iowa Department of Natural Resources, and it is regulated and inspected by state authorities. The dam has a storage capacity of 91 acre-feet and covers a surface area of 7.5 acres, with a drainage area of 0.56 square miles.

Managed by the USDA NRCS, Mason Dam is primarily an earth dam with a soil foundation. It has a low hazard potential and is classified as being in moderate risk. The spillway type is uncontrolled, and there are no outlet gates or associated structures. While the dam's condition assessment is not rated and it has not been inspected since October 1964, it meets state regulatory requirements and is considered to be in compliance with enforcement measures. Despite its age, Mason Dam continues to serve its intended purposes effectively and safely for the surrounding environment and community.