Dam Project Update

     

February/March 2020 Dam Project Update

  

March 13, 2020


Welcome to almost spring campers!


Hope all is well with everyone. Just an update on the Web Site   and Dam Project.

We changed the format for the Dam Project and split it into 2   separate pages. There now is a page for 2019 Dam Project which is comprised   of what mainly was there before. A new, second page was added for 2020 Dam   Project. These are still under the header Lake Projects. This was needed   because the limitation of content allowed for each page. We will be tweaking   these as time goes on.


Dam Project Update.

The Contractor has met all the milestones required so far.   Much of the earth work was shut down for the winter but once the weather   breaks and temperatures rise they are ready to continue the large earth work   remaining. 


 Some great progress has been made the past couple of months. They were able   to clean out the bottom of the over flow spillway of organics, trees, bushes,   and junk that has accumulated through the years. They were able to build a   small “road” for the large trucks to bring the stone in at the bottom. I have   added a couple of pictures showing what a great job they did and how nice it   looks. They also installed the revetment stone on the northeast waterside of   the dam.


This week, March 14th, or next they should complete the final   pour on the final lower spillway wall. Once this is cured, we can crest. The   Dam Road cut for the siphon pipes has been sealed and filled to an elevation   of above 1280, which is above the crest level should the level rise. The rest   of the road cut will be filled eventually to the actual road grade. They need   warm weather so it can be compacted every few inches and ultimately repaved.


Now the bad news, although the level is up ahead of the   original projection, currently recovered over 4 and a half feet. As of   3/13/20, the level was 1274.47 which is approximately 5.5 feet below crest.   Most of the snow pak has melted and the long term forecast doesn’t look like   any large March snow storm is in the offing…….but it is Syracuse. Without   rain and snow melt to fill the Reservoir, the level rise will slow down   substantially. So as much as we don’t want a wet spring or early summer, we   may have to do some rain dances to get the level to crest or at least close.   Keep the fingers crossed.


The temporary diversion structure will not be used due to a   couple of issues. The Susquehanna River Basin Commission started throwing   curve balls at the State. The most important one was they wanted the state to   put in flow monitoring on the temporary pipes that were already installed.   This caused many issues most important is there’s no electricity there.


(Now let me take liberty with a personnel editorial to explain   something in MY own words. It’s BS (that’s beautiful Sunday for the children)   what the Susquehanna River Basin Commission asked of the State. For centuries   it has been known what volume of water can flow through a given size pipe.   Even when valves are installed, which the state did to control the volume to   meet the SRBC requirements wasn’t good enough. They wanted electronic   monitoring for a small amount of water for a short duration of time. The   State made the right call in my opinion. End of editorial comment).


Now, the good or bad depending on how you look at it. The   volume/rate of water the SRBC was going to allow wouldn’t make a large   difference in cresting the Reservoir. On the positive side, we won’t be   bringing in any excess nutrients from outside the watershed. So, it is what   it is. The State did everything they could do. Now we need the rain and lots   of it.


Once the ice is gone, the Contractors will be able to start   doing the waterside work. They will have a large barge and under water divers   to install the “suction” side of the siphon pipes down to the bottom where a   new trash rack will be installed. Warning buoys and other minor tasks will   also be completed.


The 22 inch siphon pipes between the upper and lower valve   house will be installed. The weir boxes for flow monitoring will be installed   and the siphon system will be tested and made operational. Once that is done,   the 3 original drain pipes and the old valve house will be decommissioned and   the pipes grouted and sealed and the valve house filled with sand. The two   access roads will be completed and the fill will be brought in to raise the   grade in various areas in the east and west buttresses. It will be seeded and   the Dam Road will be paved and reopened. The time frame now is dependent on   weather mainly. The project could be completed anywhere from June into the   fall assuming things continue to go as planned.

The Dam Project web page has been updated with this   information and some pictures of the work.

https://deruyterlakeassociation.org/2019-dam-project



Construction Update 1-13-20


Most milestones have been met per the design schedule. Most earth work on the west and east buttresses have been scaled back for the winter. The water level can now rise due to the Reservoir being isolated from the Valve House with the installation of the two 20 inch valves in the new Upper Valve House. The level was about 7 3/4 feet below crest level on 1/23/20 and should continue to slowly come up. It will be maintained at the 3-5 foot level below crest until spring buttress work can be completed,


 Upper Spillway Chute concrete work is progressing slowly due to temperatures. The work will continue but Contractor reports it's getting harder due to cold temperatures. They are heating the area in sections to be able to pour the concrete walls and keep them warm for curing.


There will be some heavy work done at the toe/base of the overflow spillway including removing the debris and organics. Then a large amount of revetment/stones used for energy dissipation of the flows  to prevent scouring can be brought in and be ready for any overflow (hopefully) this late spring/summer. The Contractors have begun a road to access the area with some heavy equipment if possible.



Construction Update 1-3-20


Great News-


The contractor has met the milestone of completing the elevation of the Dam Rd. Cut to 1280 feet in elevation with the installation and covering of the Siphon Pipes through the Dam. This is .2 tenths above crest level of 1279.8 feet above sea level and no more fill is expected through the winter.


The outlet gates are at a minimum now and the level is beginning to rise. We are about 1.2 feet above the 10 ft drawdown level. Current reading is 1271.05, which is approximately 8 and 3/4 of a foot below crest. There is very little snow pack left in the hills as a result of earlier rain so most inflow into the Reservoir is reduced. Temperatures are cooling for the weekend but will tend to moderate next week. There is no major snow predicted for the coming week.


Using the predictive model the State Engineers developed as part of the  design of the project and was presented at their information meetings, we are ahead of the predictive model regarding filling the Reservoir. I will attempt to put up the model again under one of the current headers or perhaps a separate one now that the state electronic gage is reporting to the link.


There is a meeting scheduled next week regarding using the newly installed and temporary  diversion channel. I will update this page if a decision is made. 


The spillway concrete work is proceeding and is expected to be completed perhaps by mid-February.




Construction Update 12-29-19


Met with state engineer on 12-29-19 and the progress continues’ albeit at a slower rate due to weather/winter setting in and rain. But they are still on schedule to begin allowing Reservoir level to start to come up in the near future. Now we need snow pack to build in the hills and lots of rain in the spring to crest the Reservoir if possible for the summer season.



Construction Update 12-16-19. 


Discussed status with on-site Construction Supervisor and State Inspector/Engineer and they are pretty much ahead of schedule. In fact, they have mostly met December’s schedule and have started worked into the January schedule. They have plans to work Christmas Eve. Much of the large earth work will slow down due to weather/temperatures.


The best news is the two 22 inch siphon pipes and an 8 inch priming pipe has been installed in the dam and they have started backfilling and compacting. The fill material requires compaction every 6 inches. They have about 5 feet done now so they will hold off until January as there is no concern should the Reservoir level rise. In January they will continue fill. The ground his being kept warm with tarps and heating coils. Soil is being brought in from a heated barn so it’s dry and warm to meet the specifications for compaction.


The upper valve house concrete has mostly been poured and work on the lower valve house is being readied for concrete.


The Overflow Spillway floors have all been poured and the wall concrete will be started soon. They did a test sample with the stamp form yesterday. These forms were required by the Historical Society to make the walls look like the original stone.


  

Update on Dam Project 11-26-19


We met with the State Inspectors on November 26, 2019 to discuss project status now that the construction season is beginning to wind down somewhat with the approach of winter. We also throughout the construction have met and discussed issues with the State Inspectors and the Contractor. Both have been completely open, honest and helpful dealing with any concerns we have brought up.


First per state and contractor we are at or slightly ahead of schedule even with the amount of rain through November. The priority of worked to be completed has shifted to complete all required work to allow filling the Reservoir by December 31, 2019. Barring any major calamities and extreme weather events, the schedule should be met.


So here is what is scheduled to be completed before the end of the year. The Upper Valve House Concrete is scheduled to be poured on 11-27.  The Lower Valve house is projected to be poured before the end of the year.


The two 22 inch siphon pipes will be installed through the dam cut and the dam cut will be filled to above crest level.


The overflow spillway concrete will be completed to handle any crest next spring/summer (keep the fingers crossed). The newly constructed drop sections after the bend will be completed and more sheet piles will be added at the base of these to provide stability of the structure. These like the ones at the bend will be 40 foot sheet piles. A large amount of revetment to act as energy dissipaters at the base/end of the concrete spillway may be completed this year although it’s not required for cresting.


The large Earth work will slowly be curtailed due to inability to compact wet or frozen material. Weather will be the main determinate on how much work can be done.


The collection piping and manhole setting in the western buttress will try to be completed and some fill brought in to start to bring up the grade although not required to crest. Final fill and grade will be completed next year.


The diversion work on the temporary diversion channel started the week of 11/25 anticipating withdrawal approval from the Susquehanna River Basin Commission in the near future.


The Dam Road will remain closed through the winter most of the construction next year.


Installation of various piping for normal withdrawal amounts, connecting the 22 inch siphon pipes to the valve houses, completion of the valves and operational equipment in the houses will be done next year although some can be done through the winter possibly. The complete siphon system/works has to be totally completed and operational before the current valve house and control valves are abandoned.


Most of the water side work will be done next spring/summer. This will include running the siphon pipes to the bottom and into the trash racks and anchoring them with concrete blocks for stability. Adding the check valves to the lines will also be done next year. This will require a considerable amount of underwater work.

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Dam Update 11-23-19 


As the construction season begins to wind down the state engineers are on schedule. We were extremely fortunate to have a dry September and October allowing the Reservoir to drop the ten feet needed to begin the construction. 

Unfortunately, as we all know, this particular project is extremely dependent on weather. We had some rain and snow in November that slowed the progress, but they are still on target to be able to "close up" the dam and finish the over flow spillway complete rebuild by the end of December absent any major issues arising.


The state has as their number one priority now to complete needed repairs to begin filling the Reservoir by December 31st. Most of the eastern buttress work will be completed as well as the overflow spillway. Work on the western buttress including working around the federal wetland, completing the upper and lower water works including the siphon piping and valve house will proceed next spring and summer. This work does not anticipate lowering the summer level assuming the Reservoir recovers from the 10 foot drawdown.


While some work can and will continue through the winter, the main issue is much of the fill required for the western buttress can not be compacted safely plus a large water content also impedes compaction. The last thing we want is for a "blow out" and the State Engineers and Contractor are committed to completing a quality job.

It is also expected that the Dam Rd will remain closed through the winter and next spring at least.


Check back for any updates as we get them.