National Dam Inspection Program. Comet Lake Dam (NDI I.D. Number PA-00796, PennDER I.D. Number 28-103), Potomac River Basin, Spring Run, Franklin County, Pennsylvania. Phase I Inspection Report,
GAI CONSULTANTS INC MONROEVILLE PA
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Based on a visual inspection, operational history, and hydrologichydraulic analysis, the dam is considered to be in fair condition. The size classification of the facility is small and its hazard classification is considered to be high. In accordance with the recommended guidelines, the Spillway Design Flood SDF for the facility ranges between the 12-PMF Probable Maximum Flood and the PMF. Due to the high potential for damage to downstream structures and possible loss of life that could be associated with a sudden breach of the embankment, the SDF is considered to be the PMF. Results of the hydrologic and hydraulic analysis indicate the facility will pass andor store only about 44 percent of the PMF prior to embankment overtopping. A breach analysis indicates that failure under less than 12-PMF conditions would likely not lead to increased downstream damage or loss of life. Thus, based on the screening criteria contained in the recommended guidelines, the spillway is considered to be inadequate, but not seriously inadequate. If the embankment crest was regraded to its original design elevation, the facility would pass andor store approximately 73 percent of the PMF prior to embankment overtopping, but would still be considered inadequate.
- Civil Engineering