National Dam Safety Program. Indian Rock Lake Dam (MO 31033), Mississippi - Kaskaskia - St. Louis Basin, Franklin County, Missouri. Phase I Inspection Report.

This report assesses the general condition of the dam with respect to safety, based on available data and on visual inspection, to determine if the dam poses hazards to human life or property. The inspection team concluded that the dam is unsafe. Based on the criteria in the guidelines, the dam is in the high hazard potential classification, which means that loss of life or appreciable property loss could occur in the event of failure of the dam. A subdivided recreational development with several dozen numbered lots is located adjacent to the creek within a mile below the dam. These lots are apparently in frequent use for camping. Several downstream residences would also be subject to possible damage. The dam is in the intermediate size classification since it is more than 40 feet high. A major earth slide was present on the downstream face. Excessive seepage was occurring through and beneath the dam and its abutments. The spillway in the right abutment is inadequate to pass any flow without overtopping, because the invert of the spillway is higher than the top of the dam.