Back to Plan 2014 after water level drop slowed along Lake Ontario

Niagara Gazette, Niagara Falls, N.Y.
·2 min read

Oct. 1—The International Lake Ontario-St. Lawrence River Board has gone back to following Plan 2014 directives as Lake Ontario levels continue their seasonal decrease.

On Sept. 2, the board began deviating from Plan 2014 to provide higher and more predictable water levels on Lake St. Lawrence and the upper St. Lawrence River.

Dry weather conditions have caused water levels on Lake Ontario to decline below the 245-feet threshold. As of Saturday, the "September Rule" will no longer apply.

The board's deviation strategy helped slow the seasonal decline of water levels on Lake St. Lawrence and the upper St. Lawrence River. Since Sept. 2, water levels of Lake St. Lawrence have been 2 to 8 inches higher than they would have been had the board not deviated. Conversely, water levels downstream of the Moses-Saunders Dam were 2 to 6 inches lower than they otherwise would have been. The level of Lake Ontario is currently 0.8 inches higher than it would have been if the board had not deviated.

Through Oct. 13, the board will continue to set flows in accordance with the applicable Rule Curve flows prescribed by Plan 2014. Outflows are expected to continue to decrease in the coming weeks, as the level of Lake Ontario continues its seasonal decline.

The board will not conduct an additional flow reduction in early October for boat haul-out in Lake St. Lawrence. As water levels throughout the system continue their seasonal decline, the board encourages recreational boaters to monitor the water level forecasts to determine the optimal time to remove their vessels and equipment for the season. The board also encourages boaters to take wind effects into account. Sustained northeasterly winds cause Lake St. Lawrence water levels to decrease.

As required by the IJC's directive, the deviation from the September Rule will be completely offset from approximately Oct. 14 through Nov. 17. The board will set flows 150 m3/s above the applicable Rule Curve flows, for approximately five-weeks, as conditions permit. The Board's offsetting deviation strategy may be adjusted depending on weather and water supply conditions.

Lake St. Lawrence water levels are expected to decline more rapidly beginning on October 14 when the Board begins offsetting deviations.

For more information on:

—Lake Ontario Outflow Changes: https://ijc.org/en/loslrb/watershed/outflow-changes

—Water Levels: https://ijc.org/en/loslrb/watershed/water-levels

—Water Level Forecast: https://ijc.org/en/loslrb/watershed/forecasts

—Review of Plan 2014 https://www.ijc.org/en/glam/glam-expedited-review-plan-2014-phase-2