National Dam Safety Program Lake Paho Dam Mo 10108 Missouri Grand Chariton Basin Mercer County Missouri Phase I Inspection Report PDF Download

Bethany City Reservoir Dam was inspected by an interdisciplinary team of engineers. The purpose of the inspection was to make an assessment of the general condition of the dam with respect to safety, based upon available data and visual inspection, in order to determine if the dam poses hazards to human life or property. Our inspection and evaluation indicates that the spillway does not meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. The spillway will pass 25% of the Probable Maximum Flood without overtopping the dam. The Probable Maximum Flood (PMF) is defined as the flood that may be expected from the most severe combination of critical meteorologic and hydrologic conditions that are reasonably possible in the region. Additional deficiencies, in accordance with the guidelines, are the lack of seepage and stability analysis. These analyses should be obtained in the future. Other deficiencies visually observed by the inspection team were many small trees and brush growing on both embankment slopes, rodent holes and burrows on the downstream slope, a small crack parallel to and downstream from the centerline of the dam, a bulged area in the embankment downstream from the crack, a boil adjacent to the pumphouse caused by a broken water main and spalling of the concrete in the cap on the spillway.