MASSENA -- A release of water near Massena from upstream along the St. Lawrence River could cause unsafe water and ice conditions near Long Sault Dam.

The gates at Long Sault Dam may need to be opened as early as Thursday to spill excess water from the St. Lawrence River, according to a press statement from the New York Power Authority.

NYPA warns that a spill through the dam will result in rapidly changing river flows and potentially unsafe ice conditions along the South Channel of the river, downstream of the dam.

Members of the public, including those ice fishing on the river or channel, should be alert to rapidly changing ice conditions and should stay off the ice. NYPA warns. A map detailing affected areas is available here.

A warning siren at the dam will sound just prior to the release and before any flow changes through the dam.

NYPA makes these recommendations:

• Keep back a minimum of 800 ft. from the Long Sault Dam spillway and Robert Moses Power Dam, both on the upstream and downstream side.

• Use caution on and near the river.

• Be aware of changing river conditions and strong currents.

• Spilling water at Long Sault Dam can occur with very little notice, so caution and awareness along the river, especially in the South Channel, and near the Long Sault Dam spillway and the Robert Moses Power Dam is advised at all times.

Water flows from Lake Ontario into the St. Lawrence River are governed by the International Joint Commission (IJC).

The action to increase outflow this week is in response to higher than normal water levels and ice conditions on Lake Ontario and is in accordance with international treaties and the Plan 2014 agreement that dictates how flow changes occur on the St. Lawrence River. Actual outflows will depend on conditions in the St. Lawrence River. Spilling activities could take place through the remainder of winter and through the spring.

For more information on marine conditions visit the Great Lakes St. Lawrence Seaway System website at http://www.greatlakes-seaway.com/en/.