National Dam Safety Program. Morris Lake Dam (NJ00306). Hudson River Basin, Tributary of Wallkill River, Sussex County, New Jersey. Phase I Inspection Report.

Abstract

Abstract : Morris Lake Dam, classified under high hazard potential category, is in fair overall condition. The structural stability of the dam is uncertain. The concrete gunite facing on the down stream face of the dam has numerous large cracks and is separating from the dam in areas. There is seepage through one of the cracks. Spalling and deteriorating concrete exist at a number of locations on the upstream and downstream face of the dam, and are particularly severe at the east upstream abutment and on the spillway wingwall near the west abutment. The condition of the original masonry dam within the present dam is unknown. There is now emergency low level outlet for the dam. There is no engineering data available concerning the design or construction of the original dam or subsequent modifications. The spillway capacity, as determined by the Corps of Engineers screening criteria is inadequate. The dam can adequately pass only 50% of the probable maximum flood. The following are recommended to be done soon: Perform additional investigation to determine seepage conditions through and under dam, the engineering properties of the dam and foundation, ad whether or not conventional safety margins exist under more severe stress conditions than those observed during our inspection, and, what modifications may be required to achieve such safety margins. provide emergency low level outlet for the dam. Repair areas of spalled and deteriorated concrete on the dam appurtenances.