After nearly a year, the Whaley Lake Dam reconstruction project is entering its final stages. The work continued on schedule throughout the summer, in spite of inclement weather conditions. On the progress of the project, Owner’s Representative Vinny DiMarco said “we’re 99.7% completed. We’ve really come a long way.”
The last major concrete pour at the dam took place on August 31, on the structure’s energy dissipation wall. To date, 1,645 cubic yards of cement have been used as part of the reconstruction effort. This equates to 3,290 tons of material, as well as an additional 20 tons of reinforcing steel used.
The new spillways at the dam were constructed to match the specifications of the previous spillway structure. The new spillway stands at 704.8 feet above sea level, while the secondary spillway is 707.5 feet, and the highest point at the crest of the dam reaches 712 feet above sea level. When completed, the top of the dam will be topped with three feet of low permeability fill, which will blend with the natural surroundings.
Following the final concrete pour, workers are now engaged in the slow process of backfilling the structure. The fill material, provided by Peckham Industries in Patterson, must be added in 12-inch increments and is constantly checked for compliance to compaction and moisture content regulations. Readings of these materials are taken by Advance Testing of Newburgh, NY, to ensure all proper standards are met as the dam’s buttresses, walls, and spillways are backfilled. In addition, the entire structure will be armored with a layer of large, uncoursed stone known as riprap for further reinforcement and to prevent erosion. The dam’s spillway, which will distribute water to surrounding wetlands, is also receiving a final concrete polish.
As the project nears completion, the backfilling process will be the primary task. However, crews will also need to remove the cofferdams used during construction, as well as the temporary spillway. Workers will also be installing topsoil on the crest of the dam, with all projects slated to be completed by the end of October or early November. At that point, a timetable will be set for restoring the water in Whaley Lake to design and historic levels of 705 feet above sea level.
The dam’s new spillway, as well as weir boards in the structure’s drawdown chamber and sluice gate will allow officials to have better control over the water level in Whaley Lake. “We can control the lake level when need be,” explains DiMarco. “If we had a huge storm coming, we would be able to lower the lake water level to accommodate the storm rainfall. We can also see if lowering the lake will control lake weed growth. We’ve had six feet of water missing from the normal pooling elevation for the past year. We’ll know next spring if lowering the lake water level is the remedy for preventing lake weed growth.”
With the end of the reconstruction effort in sight, DiMarco reports that the effort remains on budget and on schedule. He credits the efforts of not only the workers involved, but also the residents of the surrounding areas for the project’s success: “It’s a beautiful project. We owe a lot of this to Winn Construction. Our crew has been excellent, they’re hard workers who never stopped even when the weather got bad. I also have to thank the residents of Whaley Lake. They were patient, have cooperated, and they let us work uninterrupted.”