National Dam Safety Program. Silver Lake Dam (NJ00469), Wallkill River Basin, Tributary to Franklin Pond Creek, Sussex County, New Jersey. Phase I Inspection Report

摘要

Based on visual inspection, past operational performance and Phase I engineering analyses, Silver Lake Dam is assessed as being in good overall condition. Based on investigations of the downstream flood plain made in connection with this report, it is recommended that the hazard potential classification be downgraded from high to low hazard. Hydraulic and hydrologic analyses indicate that the spillway is inadequate. Discharge from the spillway is not sufficient to pass the designated spillway design flood (100-year storm) without an overtopping of the dam. The spillway is capable of passing approximately 4 percent of the SDF. However, because of the low hazard classification, no further studies or increase of spillway capacity are recommended. The observed seepage at the left side of the dam at the toe of slope should be monitored on a periodic basis by a professional engineer experienced in the design and construction dams in order to detect any changes in volume or condition.