Recent events indicate the New York Power Authority’s small hydroelectric facilities on the Mohawk River remain vulnerable not only to flooding disasters but to heavy rainfall, as well.
NYPA recently announced completion of a repair project at the Crescent hydroelectric plant straddling Saratoga and Albany counties, giving local anglers back a popular fishing spot near the site.
The fishing hole was closed in December to make room for repair work on an underwater electrical cable damaged during Tropical Storm Irene nearly two years ago.
Just upstream, at the Vischer Ferry hydroelectric plant opposite Lock 7 in Niskayuna, an earthen embankment failed during the throes of Irene, causing NYPA to announce a Type B emergency followed by emergency fortification work.
According to NYPA spokeswoman Maura Balaban, the embankment still needs more work to ensure it’s secure.
“Beyond measures taken by NYPA immediately following Irene, NYPA plans to take further action to fortify the earthen embankment at Lock 7,” Balaban said in an email last week.
“These plans include raising the concrete core wall by three feet. We will issue formal notifications as the schedule is finalized and the work draws near,” Balaban said.
Weather-related failures at the small hydroelectric facilities aren’t confined to times of disaster, but heavy rainfall such as that which hit the region in late May. Several planks situated on top of the Vischer Ferry dam were destroyed and, according to a notice issued by NYPA Friday, at the Crescent plant as well.
The planks, called “flashboards,” are used as part of a rudimentary water-level control to boost the depth of the Mohawk River and maintain levels for navigation along the Erie Canal.
The system was developed when the Vischer Ferry plant was built in around 1913.
Work to re-install the flashboards was planned before another rainfall event earlier this month and then canceled due to high water last week.
NYPA on Friday announced plans to work on the flashboards atop both the Crescent and Vischer Ferry dams starting today. The work will require drawing down the Mohawk River levels to about two feet below normal summertime depths.
The work as planned will take place Tuesday through Thursday and NYPA estimates water levels will be restored to normal depths on Friday.
No announcement was made by NYPA following an incident in early April, but a recent submission by the authority to federal regulators suggests the Vischer Ferry hydroelectric plant had another failure.
NYPA provided the Federal Energy Regulatory Commission with an incident report on the failure of a “slide gate” at the Vischer Ferry plant on April 11.
NYPA spokesman Michael Saltzman in an email Friday said the facility has six gates used occasionally to lower the water levels, and one is out of service.
“Although one gate is currently out of service, the other gates have sufficient capability for the water management function that they’re utilized for. There is no public safety issue whatsoever and NYPA is undertaking the necessary repairs of the gate in question, with the work expected to be completed by mid-July,” Saltzman said in the email.
Post-Irene repairs at NYPA’s other small hydroelectric facility — the Blenheim-Gilboa pumped storage power project in Schoharie County — are nearly complete, according to Balaban.
The Schoharie Creek embankments just downstream were among damage the B-G facility sustained during Tropical Storm Irene, and repair work nears the end there, Balaban said in the email.
The fishing access downstream of the Blenheim-Gilboa facility, shut down roughly nine months ago for repair work, could open next month, according to Balaban.