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National Dam Safety Program. Tomhannock Spillway Dam (Inventory Number N.Y. 117), Upper Hudson River Basin, Rensselaer County, New York. Phase I Inspection Report,

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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. The Phase I inspection of the Tomhannock Spillway Dam did not indicate conditions which would constitute an immediate hazard to human life or property. However the dam has some deficiencies which require remedial work. The hydrologichydraulic analysis indicates that the dam will be overtopped by 1.1 feet by the Probable Maximum Flood PMF. However, the spillway can pass the 12 PMF with 3.7 feet of freeboard. Therefore, the spillway is assessed as inadequate according to the Corps of Engineers screening critieria. The visual inspection did not reveal conditions which would indicate evidence of structural displacement or instability. The conclusion derived from evaluating the factors involved in the spillway design and forces which could act on the spillway structure is that the stability will be retained under the PMF conditions providing the composite spillway facility remains in good condition and structurally integrated. Investigate the seepage at the toe of the earthfill embankment near the left abutment. The area should be monitored and records should be maintained to detect changing conditions which might affect the safety of the facility. Author

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  • Hydrology, Limnology and Potamology
  • Civil Engineering

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