ramblings of a catskill fly fisher

Prattsville rides again?

By TONY BONAVIST
Posted 3/24/21

I don’t remember the exact date that the Department of Environmental Conservation (DEC) became aware of the Prattsville pumped storage project proposed for the Schoharie Reservoir. The project …

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ramblings of a catskill fly fisher

Prattsville rides again?

Posted

I don’t remember the exact date that the Department of Environmental Conservation (DEC) became aware of the Prattsville pumped storage project proposed for the Schoharie Reservoir. The project was sponsored by the New York State Power Authority, known to us as PASNY. If approved, it would be the second in the region, the first being the Blenheim-Gilboa pump storage facility, which is already operational.

I do know that the DEC’s region three and region four fisheries units began a review of the project in 1974. I have photos that were taken from the DEC’s helicopter as it flew over Schoharie Reservoir, the Esopus Creek and the upper basin of Ashokan Reservoir, dated that year. The reason for the photos was to document the turbidity that would be a constant in Schoharie Reservoir, the Esopus Creek and at least the upper basin of Ashokan Reservoir, should the Prattsville project be completed.

As background, readers should know that the entire watershed that feeds the Schoharie Reservoir is replete with deposits of reddish-brown clay. Those deposits are subject to erosion during heavy rains, turning the reservoir a muddy-brown color that can last for weeks.

While reviewing the Prattsville application, DEC biologists became aware of several potential impacts that pumping operations could have on Schoharie Reservoir and the Esopus Creek. Biologists believed that the constant movement of large volumes of water between the Schoharie Reservoir and the upper reservoir during pumping/generating cycles would cause the clay deposits to remain in solution indefinitely. More importantly, biologists also believed that constant pumping action would prevent the Schoharie Reservoir from stratifying during the summer. That would mean that water temperature in the reservoir would remain homogeneous, with a little cold bottom water available for discharge through the Shandaken Tunnel into Esopus Creek during late June, July and August.

The Esopus Creek between the tunnel discharge point and the Ashokan Reservoir is dependent upon the release of cold bottom water, to provide adequate flow and temperature, to maintain its trout fishery. Biologists believed that destratification of the Schoharie Reservoir due to the operation of the pump storage facility would cause warming water trends and compromise that fishery.

Over time, the Federal Energy Regulatory Commission (FERC), which was responsible for the management of the application process and the licensing of the Prattsville project, held a number of public hearings. As a result of those hearings and analysis of the data by consultants, FERC issued a conditional license pending a water quality certification by the State of New York. The DEC, to its credit, declined to issue that water quality certificate, citing that the discharge of turbid, unacceptably warm water would negatively impact the trout population of the Esopus Creek. Despite the fact that the DEC’s decision was appealed, it was later upheld by the courts and the project ended.

Fast forward some 40 years, and there is an email from Trout Unlimited, dated February 20, in my inbox. It explains that Central Hudson Utilities in conjunction with Premium Energy Holdings, a California company, has applied to FERC to construct an 800-megawatt pump storage facility on the upper basin of the Ashokan Reservoir in the town Olive. The project is slated for land owned by the New York City Department of Environmental Protection (DEP) which claims no knowledge of the project.

So, here we go again: same watershed, same issues. The upper basin of Ashokan Reservoir is fed by the often turbid waters of the Schoharie Reservoir and the Esopus Creek via the Shandaken Tunnel. When the Ashokan Reservoir complex was completed around 1915, the upper basin, because of the upstream silt load, was designed as a settling basin for all of that silt. Silt has been accumulating in the upper basin for more than 100 years, meaning that pumping activity would cause the upper basin to remain off-color indefinitely. As a result, those fishes, including brown and rainbow trout would have difficulty finding food items, such as plankton and forage fish, to feed upon. In addition, there is the possibility, depending on the volume of water required to fill the upper reservoir as compared to the volume of water available in the lower basin of Ashokan Reservoir, that destratification would occur. If destratification did take place, the resultant warmer water temperatures could impact brown and rainbow trout populations living in the upper basin. It is also probable that the entrainment of eggs and larvae of fish like walleyed pike would be subject to the pressure changes associated with the pumping cycle. As a result, many of those organisms would die. There’s also the possibility, depending on the level that the upper basin is drawn down during the pump-up cycle, that spawning beds of inshore spawners like bass and sunfishes would be exposed to the air and perish.

The upper basin of the Ashokan Reservoir is approximately twice the size of Schoharie Reservoir, so the impacts associated with pump storage operations on that basin are unknown at this time. Nevertheless, the issues outlined regarding turbidity, destratification, entrainment and drawdown on inshore spawners need to be thoroughly addressed before any permits or licenses are issued. That process will involve public hearings and take several years to complete.

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