Koop Dam, located in New Hartford, Iowa, is a privately owned earth dam completed in 1990 for fire protection, stock, and small fish pond purposes. The dam stands at 28 feet high with a length of 328 feet, providing a storage capacity of 51 acre-feet and a surface area of 4.6 acres. Situated on the TR- Beaver Creek, the dam is regulated by the Iowa Department of Natural Resources and is subject to state permitting, inspection, and enforcement.

Despite its low hazard potential and moderate risk assessment, Koop Dam has not been rated for its condition assessment. The dam features an uncontrolled spillway type with no outlet gates or associated structures. The last inspection was conducted in October 1991, highlighting the need for more frequent evaluations to ensure the safety and integrity of the structure. With its strategic location and purposeful design, Koop Dam serves as a vital resource for water management and conservation efforts in the Butler County area of Iowa.