Lake Ontario outflows increased by board

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

Oct. 18—Lake Ontario outflows have been increased above the amount set by Plan 2014. The process began Saturday and will continue for approximately eight weeks to return water levels in Lake Ontario to the level it would be had outflow deviations not been required earlier this year.

Drought conditions in spring 2021 caused water levels on Lake Ontario to decrease below the Criterion H14 major deviation threshold. As required by the International Joint Commission's (IJC) Directive, the regulation plan needs to be followed unless water levels reach any of the defined triggers specified in the directive. Therefore, the International Lake Ontario-St. Lawrence River Board decreased outflows from May 29 through July 16, until water levels on Lake Ontario increased above the Criterion H14 major deviation threshold. The summer deviations maintained an extra 1.6 inches of water on Lake Ontario relative to Plan 2014.

In addition to the summer deviations, the board decreased outflows from Oct. 8 through 11 under the minor deviation authority as defined in the IJC's directive. The October deviation was made to improve conditions on Lake St. Lawrence for boat owners to remove boats at the end of the boating season. The October minor deviation caused an increase of approximately 0.3 inches of water on Lake Ontario, compared to Plan 2014. The summer and fall deviations resulted in a combined total deviation of 1.9 inches. The increased outflows scheduled from mid-October through mid-December will remove the 1.9 inches of water that was maintained on Lake Ontario.

The board expects to return to Plan 2014 prescribed outflows in mid-December.

"In accordance with the Directive, the Board must obtain IJC approval for strategies to return to plan flows through what is known as equivalent offsetting deviations, or payback", said David Harper, Canadian co-chair of the International Lake Ontario-St. Lawrence River Board.

"Lake Ontario remains a natural system and is not a reservoir", said Steve Durrett, U.S. co-chair of the International Lake Ontario-St. Lawrence River Board. The record-keeping system for deviations operates like a check book that is eventually balanced and enables the Board to return the system to the water levels that would have occurred under Plan 2014 after outflows have been influenced as required by IJC's Orders and Directive.

Information on hydrologic conditions, water levels, and outflows, including graphics and photos, are available on the board's website and posted to the board's Facebook page at https://www.facebook.com/InternationalLakeOntarioStLawrenceRiverBoard, and more detailed information is available on the website at https://www.ijc.org/en/loslrb.