National Dam Safety Program. Winnetonka Lake Dam (MO 11011), Missouri - Kansas City Basin, Clay County, Missouri. Phase I Inspection Report.

Winnetonka Lake Dam was inspected by a 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 a 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 and trench will not pass the probable maximum flood without overtopping but will pass 20 percent of the probable maximum flood, which is greater than the 100-year flood. The spillway design flood recommended by the guidelines is 50 to 100 percent of the probable maximum flood. Considering the volume of water impounded and the downstream hazard, 50 percent of the probable maximum flood is the appropriate spillway design 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.