Engineer outlines plan for dam rehabilitation
SUSSEX BOROUGH — The Sussex Borough Council on June 2 learned it could face up to a $93,000 bill for studies to determine the necessary upgrades to the borough-owned Lake Rutherford Dam.
Chris Adams, a representative for Civil Dynamics engineering firm, said the dam's spillway capacity needs to be larger and has been labeled a high-hazard dam because a dam failure could result in a probable loss of life.
The Department of Environmental Protection requries the dam be inspected every two years.
The DEP also wants inundation maps prepared for the Emergency Action Plan to give to the Offices of Emergency Managements in order for the state police to know who needs to be evacuated.
There will be two phases to the study. Phase I, which would cost $32,000 would be a hydrologic and hydraulic study plus an EAP report, which was due to the EAP by May 31. The borough could be subject to penalties of about $5,000 due to the missed deadline but Adams said he will develop the mapping and send a letter to the DEP asking for an extension on the deadline.
The second phase, which will bring a $56,000 price tag will be a study of the probable maximum precipitation of 34 inches of rain in a 24-hour period. In theory, the dam would break under so much rain.
Council President Marina Krynick asked when the last time so much rain fell in such a short period of dam, pointing out the dam survived Hurricane Irene and Superstorm Sandy and "has been there 100 years."
Adams said a controlling factor is the risk of probable loss of life. The DEP is following a national standard which is in effect for New Jersey, New York, Pennsylvania and the federal government.
The standard has been on the books since the early 1980s and probably will not change, Adams said. The 100-year storm standard has gone up because of events.
The standard is arrived at by "a bunch of egg head meteorologists getting together with a bunch of data. There is a small probability of it actually occurring,” Adams said.
Once Phase I is submitted to the DEP, it could take 6-9 months for the report to be reviewed.