South Walnut Lake, located in Faribault County, Minnesota, is a state-regulated water resource managed by the Minnesota Department of Natural Resources. This dam, completed in 1931, serves a primary purpose that is classified as "Other," with a height of 6 feet and a storage capacity of 3000 acre-feet. The lake covers an area of 800 acres and has a normal storage capacity of 2400 acre-feet, providing vital water resources for the surrounding area.

The dam at South Walnut Lake is classified as a buttress core type structure with a fair condition assessment and low hazard potential. It has a hydraulic height of 2.1 feet and a structural height of 10 feet. The dam is situated on the Blue Earth River East Fork and has a drainage area of 115 square miles. With a maximum discharge capability of 1329 cubic feet per second, the dam plays a crucial role in managing water flow in the region and mitigating flood risks.

Despite its age, South Walnut Lake continues to be actively inspected, permitted, and regulated by the Minnesota Department of Natural Resources. The dam's last inspection took place in November 2008, with a scheduled frequency of every 8 years. With its strategic location and functional design, South Walnut Lake serves as a key water resource for the community and a testament to effective water management practices in the region.