This report was prepared under the National Program of Inspection of Non-Federal Dams. 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. (Author).

Zander Lake Dam is located in Montgomery County of the State of Missouri on an unnamed tributary of the Scratchers Branch of the Little Loutre Creek. The purpose of the dam is to impound water for recreational use as a private lake. The visual inspection uncovered nothing of a consequential nature which would require immediate remedial action. However, some conditions were observed which could adversely affect the dam and the spillway in the near future.

This dam appears to be in satisfactory condition. However, the dam does not have adequate spillway capacity. Considering the number of inhabited dwellings, a state highway and an oil depot being located downstream of the dam, the PMF is considered the appropriate spillway design flow for A.C. Schneider Lake Dam. The inspection and evaluation indicates that the reservoir/spillway system can accommodate approximately 5 percent of the Probable Maximum Flood without overtopping the dam. It also indicates that the reservoir/spillway system can not accommodate the one-percent chance flood without overtopping, however, the reservoir/spillway system of A.C. Schneider Lake Dam can accommodate the ten-percent chance flood without overtopping. Other deficiencies noted by the inspection team were: the erosion gully along the downstream left abutment/embankment contact, the trees on the downstream and upstream slope of the dam, wave erosion on the upstream slope, the unsupported length of the principal spillway pipe at the outlet, the eroded gulley in the emergency spillway channel, some vegetative growth around the principal spillway inlet, a need for periodic inspection by a qualified engineer and a lack of maintenance schedule. The lack of seepage and stability analyses on record is also a deficiency that should be corrected.

Riss Lake Dam was inspected 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 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 not pass the probable maximum flood without overtopping but will pass 90 percent of the probable maximum flood, which is greater than the estimated 100-year flood. The spillway design flood recommended by the guidelines is 100 percent of the probable maximum flood. The probable maximum flood is defined as the flood discharge which may be expected from the most severe combination of critical meteorologic and hydrologic conditions which are reasonably possible in the region. Deficiencies visually observed by the inspection team were erosion of the upstream face due to wave action, ponded water on the dam crest due to poor drainage of rainwater, trees and brush growing on the embankment, animal burrows, and seepage at several locations below the dam.

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. This dam has been classified as unsafe, non-emergency by the St. Louis District as a result of the application of the following criteria: (1) Spillway will not pass 50 percent of the Probable Maximum Flood; (2) Overtopping could result in dam failure; and (3) Dam failure significantly increases the hazard to loss of life downstream.

The purpose of this 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. The inspection and evaluation indicates the spillways do not meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. The spillways will pass 55 percent of the probable maximum flood, which is greater than the 100-year flood, without over topping the dam. The spillway design flood recommended by the guidelines is the probable maximum flood. The probable maximum flood is defined as the flood discharge that may be expected from the most severe combination of critical meteorologic and hydrologic conditions that are reasonably possible in the region. Deficiencies visually observed by the inspection team were minor seepage through the spillway weir wall, erosion on the upstream embankment, minor deterioration of the concrete weir, separation of riprap, brush growth on both faces of the structure, and a slide area on the downstream face. There were no observed deficiencies or conditions existing at the time of the inspection which indicated an immediate safety hazard. Future corrective action and regular maintenance will be required to correct or control the described deficiencies.