Greenfield Dam, located in Jefferson County, Iowa, is a privately-owned structure designed by the NRCS and completed in 1998. With a primary purpose of serving as a fire protection, stock, or small fish pond, this earth dam stands at a height of 35 feet and spans a length of 435 feet. The dam has a storage capacity of 76 acre-feet and covers a surface area of 5.3 acres, with a drainage area of 0.09 square miles.

Situated on TR- South Walnut Creek, Greenfield Dam is regulated by the Iowa Department of Natural Resources and is subject to state jurisdiction, permitting, inspection, and enforcement. The dam has a low hazard potential and its condition assessment is currently not rated. Despite its moderate risk classification, the dam has not been evaluated for emergency action preparedness, and there are no documented risk management measures in place.

Greenfield Dam, a key structure in the water resource management of the region, serves multiple purposes while ensuring the safety and protection of the surrounding community. As a significant feature in the local landscape, its construction and maintenance are overseen by state regulatory agencies to mitigate potential risks and ensure the continued functionality of the dam for fire protection, stock maintenance, and small fish pond management.