National Dam Safety Program. Jennings Pond Dam (Inventory Number N.Y. 944), Oswego River Basin, Tompkins County, New York. Phase I Inspection Report

摘要

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. Evaluation of existing conditions did not reveal conditions which constitute an immediate hazard to human life or property. However, the dam was found to have some deficiencies which require further evaluation and implementation of remedial measures. Using the Corps of Engineers' criteria for initial review of spillway adequacy, it was found that the dam would be overtopped by storms less than five percent of the Probable Maximum Flood (PMF). Because spillway capacity is less than 50 percent of the PMF and failure of the dam would increase the hazard to downstream residents, the spillway capacity is considered to be seriously inadequate and the dam is assessed as unsafe/nonemergency. Classifying a dam as unsafe because of a seriously inadequate spillway does not connote the same degree of emergency as would be associated with an unsafe classification due to a structural deficiency. It means that spillway capacity appears to be seriously deficient; and if a severe storm were to occur, overtopping and failure of the dam could result, significantly increasing the loss of property downstream of the dam. The downstream face of the dam is steep and covered with large trees and brush. The crest of the dam is irregular. Crest level ranges from 0.6 foot to 2 feet above normal pool level. Seepage and swampy conditions exist along the toe of the dam. The embankment is in need of general repair and restoration. Flattening of the downstream slope and installation of toe drains should be considered. (Author)