"After gathering supplemental data this past fall, our consultant has completed their analysis of the existing dam. Their recommendation is to augment the mass of the existing dam and modify the spillway approximately to be 90' in width vs. the current 45'. This will allow for the dam to satisfy the DEC Dam Safety hydraulic capacity requirements. The additional width of the spillway allows it to remain at the current crest elevation. This accomplished the goal of keeping the lake level the same in the pond. The two tie-in points on each side of the dam will increase slightly in height to avoid water washing around the spillway in the design storm event. The existing roads on each end of the dam will be built up and re-graded to remain passable. The new spillway was also analyzed to verify that there is not so much extra water that passes in a storm that downstream impacts are significantly greater than the current configuration.
Given the permit requirements, construction will be performed in 2015. Although this date has been postponed in the past, it is now set. The majority of the work for construction is on the downstream side of the existing dam. The existing dam will not be removed, rather new concrete will be placed around it. At this time, there is no anticipation of lowering the water for construction reasons. Our consultant is looking at alternatives for dewatering near the dam to place concrete on the upstream face. That will not impact the remainder of the pond. Storms during construction will still pass over the existing dam. Work will be phased to allow for a sufficient clear spillway opening to pass storm flows to the stream below.
Even with the fairly small increase in the overall footprint of the dam, there are still extensive permit requirements, including review by the APA and the Army Corps of Engineers. During that permit process, there will be a public comment period that is advertised in the local papers ahead of time. Comments are typically submitted to the DEC Regional Permit administrator assigned to the project, and their contact information will be advertised for the comment period.
A LATER EMAIL WENT INTO EVEN MORE DETAILS ON SOME ISSUES RAISED BY BOARD MEMBER WAYNE JOHNSON:
"Yes there will be a drawdown gate on the new dam. It is part of the requirements of NYSDEC Dam Safety that one be present. It also must have a certain capacity to release water at prescribed rates based on DEC Dam Safety criteria. The new gate will satisfy that criteria. It will be operated manually. The configuration will likely be similar to what is currently in place, with a debris rack in front to keep the opening clear. Typically gates like this have a metal connecting linkage that runs from the gate up to the operator on top of the dam.
As I noted previously, there is a defined public comment period as part of the DEC/Army Corps/APA permitting process. That period has not yet been determined but is set by Regional DEC staff and not by our office. Public comments are received and addressed before the final permit approval is issued. It will be advertised but as of right now our office does not know when it will be. I invite you to remain in contact with me and we will gladly update you as things continue to move forward.
This latest delay from 2014 to 2015 was an issue we had with our original consultant. It became very difficult to advance the project with them, and after many chances to improve their performance, we changed consultants. Our current consultant has performed many dam upgrades for our office and throughout the US. That was why I indicated that the new dates are firm for 2015 construction. Hopefully this provides a better background as to why the latest delay has occurred. While I have only been involved with the project for a few years, I can understand the perception of things from the public side given the dates of some of the prior reports I have seen from the mid-2000s."
