Dam Safety Update
Dam Safety Update Summer 2012
The report was just received by the Canal Corp. from its consultant and is currently under review prior to submittal to theNew YorkDEC. It is unclear how much of the report will be made available to the public due to the potential sensitivity of some aspects such as potential weak points listed that could prove a potential security problem.
What was obtained verbally is the following-
1-the Canal Corp. has operated and maintained the dam in a safe manner
2-the spillway meets the capacity requirements of the regulation
3-the dam is stable based on core sampling and review
1-seepage collection system is not functioning to full potential. Further investigation will be done by the CC to determine if it just may be a plugged pipe
2-the dam safety regulation requires the dam be able to be emptied in 14 days. The current gate drawdown capacity is 44 days. The CC will wait for DEC response.
3- the regulations require the gates be on the upstream side (closest to the water). Both this and number 2 above would be extremely costly to remedy. #2 would require larger pipes and or more pipes through the base of the dam and putting the gates on the upstream side would require some sort of island be built over the outlet pipes which currently extend into the reservoir. The CC will wait for a DEC response.
4-at the base/bottom of the overflow drops (punch pool) needs some work. The CC will do in-house by next year
5-the spillway masonry chute energy dissipater is gone and needs replacement. The CC may do in-house or have a consultant do a design.
6- the regulations require a slope of 3 to 1. The current backside slope is 2.5 to 1. This would be a very costly fix. The CC will wait for a DEC response.
7-General maintenance needs to be upgraded such as grass and brush cutting. The CC will do as required. They recently bought an over the hill cutter that will be able to maintain the front water side of the dam.
The above is based on verbal communications and was based on a preliminary review of the report. The CC has retained the consultant for another year to do a more detailed engineer report for design fixes should the DEC require them. This does not include any funding for major repairs. It is quite possible the actual report, recommendations, etc will not be available for public review due to security considerations. For instance, if the core sampling determined a “soft” spot in the dam, and the inundation study showed severe consequences from a breach, this would be a safety/security concern.
Further it was noted that although DeRuyter was the oldest and therefore have more problems, it should be noted that Jamesville, Eatonbrook,Madisonand Moraine have issues also, i.e. spillway capacities which is an expensive fix. The regulations also require emergency action plans be developed for all class C high hazard dams which DeRuyter is one. The CC will be developing these in conjunction with county emergency management agencies throughout the state.
If a report becomes available for public release, it will put on the web site.