HALFMOON, N.Y. (NEWS10) — The New York Power Authority (NYPA) will supervise a water drawdown to remove the flashboards at the Crescent and Vischer Ferry dams later this month. The work is meant to prepare the waterway for winter.

Flashboards are plastic or wooden planks, installed to raise water levels upstream of dams. NYPA said these activities will cause fluctuations in water levels that may affect marinas, boats, and docks.

Before the flashboard work, during the week of October 24, crews will be on the Mohawk River to remove the Vischer Ferry Boat Barrier Line, used to prevent boats from getting too close to the dam. This work is not expected to cause fluctuations in water levels.

The Vischer Ferry Dam (Lock E-7) spans the Mohawk River between Vischer Ferry and Niskayuna. The Crescent Dam (Lock E-6) is between Waterford and Colonie.

Flashboard removal schedule:

  • Sunday, October 30:
    • A gradual drawdown begins at Vischer Ferry as water levels between Mohawk River/Erie Canal Lock E-7 and Lock E-8 are lowered. Water levels will drop between two and three feet, depending on river flows at the time. The water drawdown is to be completed by Monday morning.
  • Monday, October 31:
    • Morning: Two-foot drawdown is started at Crescent as water levels between Mohawk River/Erie Canal Lock E-6 and Lock E-7 begin lowering. Removal of flashboards at Crescent is completed.
    • Afternoon: Work barge travels from the Crescent Dam to the Vischer Ferry Project. Water levels at Crescent rise about four inches, to non-navigation season levels.
    • Overnight: A second drawdown begins at Vischer Ferry as water levels between Mohawk River/Erie Canal Lock E-7 and Lock E-8 are lowered. Water levels will drop by about two feet, depending on river flows at the time. The water drawdown will be completed by Tuesday morning.
  • Tuesday, November 1:
    • Morning: Water levels at Vischer Ferry drop around seven inches. Flashboards are removed on Dam D.
    • Evening: Water levels at Vischer Ferry rise by about seven inches.
  • Wednesday, November 2:
    • Morning: Water levels at Vischer Ferry are lowered by about six inches. Fish deterrent system components are removed from Vischer Ferry forebay. Flashboards are removed on Dam F.
    • Evening: Water levels at Vischer Ferry rise around seven inches.
  • Thursday, November 3:
    • Morning: Water levels at Vischer Ferry drop by about seven inches. Flashboards are removed on Dam E.
    • Evening: Water levels at Vischer Ferry rise four inches, to non-navigation season levels.
  • Friday, November 4 – Contingency Day:
    • Morning: Work continues on flashboards at Vischer Ferry if necessary.

NYPA said work is expected to be completed by Friday, November 4. Inclement weather or high-water conditions could delay their schedule.