National Dam Safety Program. Gwenmil Lake Dam (MO 31210), Upper Mississippi - Kaskaskia - St. Louis, Basin, Jefferson County, Missouri. Phase I Inspection Report.
Abstract
The following summarizes the findings of the visual inspection and the results of certain hydrologic/hydraulic investigations performed under the direction of the inspection team. Based on the visual inspection, the present general condition of the dam is considered to be somewhat less than satisfactory. Several items were noticed during the inspection which are considered to have an adverse effect on the overall safety and future operation of the dam. These items include trees and areas of dense brush on the downstream face of the embankment, an excessively steep (as much as 1.0v on 1.5h) downstream slope, erosion of the grass covered upstream face of the dam, and a dense growth of cattails within the reservoir just upstream of the spillway. According to the criteria set forth in the recommended guidelines, the magnitude of the spillway design flood for the Gwenmil Lake Dam is specified, to be a minimum of the 100-year frequency flood and can be, depending upon the degree of risk involved, as much as one-half the Probable Maximum Flood (PMF). Considering the fact that a relatively small volume of water is impounded by the dam, that the flood plain downstream of the dam is fairly broad, that there are but three dwellings (two of which are well above the streambed) and a non-high hazard potential dam within the flood damage zone, it is recommended that the spillway for this dam be designed for the 100-year frequency flood.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1981
- Accession Number
- ADA104695
Entities
People
- Albert B. Becker Jr.
- Ralph E. Sauthoff