International Lake Superior Board of Control

ST. MARYS RAPIDS FLOW TO BE DECREASED IN PREPARATION FOR WINTER

2014/11/24

The International Lake Superior Board of Control advises that the gate setting of the control structure at the head of the St. Marys Rapids will be decreased over the course of the next two weeks. 

The current gate setting, equivalent to approximately five gates fully open, will be reduced in stages to the winter setting equivalent to one-half gate open (four gates partially open 20 centimetres (7.9 inches) each).  The gates of the control structure are typically set to this position each year at the beginning of December, and are maintained at this setting throughout the winter to aid in the establishment of stable ice conditions and reduce the risk of ice-related issues in the St. Marys River. 

If weather conditions permit, the gate setting will be adjusted in stages in order to limit the rate of decline of water levels and flows in the St. Marys Rapids.  The first gate change will take place tomorrow, Tuesday, November 25th, and a second gate change is expected to take place on Wednesday, November 26th.  If necessary, a third and final gate change may take place next week, and the Board will set the Lake Superior outflow for December at that time.