National Dam Safety Program. Kohl Irrigation Lake South Dam (MO 11208), Mississippi - Salt - Quincy River Basin, Audrain County, Missouri. Phase I Inspection Report

摘要

Kohl Irrigation Lake South Dam is located in Audrain County in the State of Missouri, and crosses an unnamed tributary of Shady Creek. As the name of the dam implies, the water impounded by the dam is used for crop irrigation. The crest and the downstream slope of the dam have a tall, dense grass cover, which adequately protects the embankment material from surface runoff erosion. However, the upstream slope has a sparse vegetative cover, and surface runoff has eroded small drainage rivulets on the order of 1 to 3 inches on the upstream face. The upstream slope also has no riprap protection and, consequently, has been eroded by wave action. Nearly vertical faces up to 2 feet high were exposed near the crest of the dam and smaller scallops were also exposed along the reservoir rim. The dam material underlying the grayish-brown topsoil cover was revealed to be a mottled red, brown, and gray, moderately plastic clay with some silt and sand. There was no evidence of seepage or leakage through or below the dam. No signs of past or present instability were seen on the embankment except for the wave eroded upstream slope.