National Dam Safety Program. Otsego Lake Dam (Inventory Number N.Y. 361), Susquehanna River Basin, Otsego County, New York. Phase I Inspection Report,
FLAHERTY-GIAVARA ASSOCIATES NEW HAVEN CT
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This report provides information and analysis on the physical condition of the dam as of the report date. Information and analysis are based on visual inspection of the dam by the performing organization. Examination of available documents and a visual inspection of the dam did not reveal conditions which constitute an immediate hazard to human life or property. However, the dam has some deficiencies that need to be evaluated and remedied. Using the Corps of Enginners screening criteria for the initial review of spillway adequacy, it has been determined that the dam would be overtopped by all storms exceeding 29 percent of the Probable Maximum Flood PMF with the flashboards in place and 30 percent without them in place. Dam overtopping, the resulting instability of the overflow spillway and hence, dam breaching would cause water surface levels downstream to reach depths which would pose significant danger to residents. Therefore, the spillway is adjudged to be seriously inadequate and the dam is assessed as unsafe, nonemergency. The classification unsafe applied to a dam because of a seriously inadequate spillway is not meant to connote the same degree of emergency as would be associated with an unsafe classification applied for a structural deficiency. It does mean that there appears to be a serious deficiency in spillway capacity and if a severe storm were to occur, overtopping and failure of the dam could take place, significantly increasing the hazard to life downstream of the dam.
- Hydrology, Limnology and Potamology
- Civil Engineering