National Dam Safety Program. Henpeck Hollow Dam (MO 31256), Mississippi - Kaskaskia - St. Louis Basin, Washington County, Missouri. Phase I Inspection Report.
Abstract
The St. Louis District, Corps of Engineers (SLD), has classified this dam as having a high hazard potential; we concur with this classification. The estimated damage zone length, as determined by the SLD, extends approximately four miles downstream of the dam. Within this estimated damage zone are a dam and reservoir (MO 31255), several dwellings and miscellaneous buildings. The dam is classified as small due to its approximately 60 ac-ft storage volume. The dam is approximately 24 ft in height. The small dam classification includes dams between 25 and 40 ft in height, or having storage volumes between 50 and 1000 ac-ft. Based on the distances to the nearest occupied dwellings, over 2.5 miles, the width of the valley downstream of the dam, on the order of 400 feet or more, and the relatively small impoundment volume, 50 percent of the PMF is recommended as the spillway design flood. The inspection and evaluation indicate the dam is in a generally poor condition. Primary reasons for this judgement are: the inadequate spillway capacity, the passage of discharge from the auxiliary spillway over the downstream slope, partial blockage of the main spillway by a beaver dam, lack of maintenance and lack of periodic inspections.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1981
- Accession Number
- ADA105138
Entities
People
- Jean-yves Perez
- Stanley F. Gizienski