Mc Call Subwatershed Site 30-1 is a significant earth dam located in Monona, Iowa, designed by USDA NRCS with a height of 41 feet and a length of 748 feet. Completed in 1963, the dam primarily serves purposes such as fire protection, stock, and small fish pond maintenance, along with flood risk reduction for the local area. With a maximum storage capacity of 80 acre-feet and a normal storage of 28 acre-feet, this dam covers a surface area of 2.9 acres and drains a 0.45 square mile watershed.

Managed by the local government, Mc Call Subwatershed Site 30-1 is regulated by the Iowa Department of Natural Resources and undergoes regular inspections and enforcement to ensure its structural integrity. Despite being rated with a low hazard potential, the dam's condition assessment is marked as "Not Rated," suggesting a need for further evaluation. With a moderate risk assessment score of 3, there is a focus on implementing risk management measures to mitigate any potential hazards and ensure the safety of the surrounding community. Overall, this dam plays a crucial role in protecting the area from various water-related risks while also providing essential benefits for local wildlife and agriculture.