Arnold-Armstrong Subwtrshd Sta 127+05 is a vital water resource infrastructure located in Monona, Iowa, specifically in the city of Castana. This structure, completed in 1963, serves multiple purposes including fire protection, stock maintenance, and small fish pond management. Managed by the USDA NRCS, this earth dam stands at a height of 36 feet and has a storage capacity of 88 acre-feet. The dam plays a crucial role in flood risk reduction for the surrounding area, with a drainage area of 1.99 square miles and a surface area of 4.7 acres.

Situated on Dutch Creek, this dam is regulated by the Iowa Department of Natural Resources and is classified as having a low hazard potential. The risk assessment for the site is moderate, with a rating of 3, indicating the need for proactive risk management measures. While the condition assessment is currently not rated, the dam is inspected, permitted, and enforced by state agencies, ensuring its safety and functionality. With its strategic location and importance for water resource management, Arnold-Armstrong Subwtrshd Sta 127+05 stands as a crucial piece of infrastructure in the region and a key player in maintaining water security and flood protection for the community.