LEVELnews

Great Lakes–St. Lawrence River Water Levels
Volume 20, Number 1

11 January 2012

No Consistent Pattern for December Water Level Changes

Although the outflow from Lake Superior was below average during December, the below-average water supply it received caused the lake's level to fall by 9 cm during December. That drop is 2 cm more than its average December decline of 7 cm. The level of Lakes Michigan–Huron also fell during December. However, due to a combination of below-average outflow and above-average water supply, the level of Lakes Michigan–Huron fell by 3 cm during December, less than its average decline for the month of 5 cm.

The levels of both lakes Erie and Ontario increased during December. However, water supplies that were well above average resulted in these levels rising several centimetres more than they typically do during December, despite above-average outflows for both lakes during the month. The levels of lakes Erie and Ontario increased by 8 and 12 cm, respectively, during December. On average, the levels of these two lakes have risen by 2 and 1 cm, respectively, during December over the 1918–2010 period of record currently used for water level statistics and comparison purposes.

 

Great Lakes Water Level Information –
December 2011 Monthly Mean Level
LakeCompared to
Monthly Average
(1918–2010)
Compared to
One Year Ago
Superior31 cm below2 cm above
Michigan-Huron30 cm below18 cm above
St. Clair18 cm above38 cm above
Erie42 cm above54 cm above
Ontario9 cm above10 cm above

 

Great Lakes Water Level Information –
Beginning-of-January 2012 Level
LakeCompared to
Beginning-of-Month
Average
(1918–2010)
Compared to
One Year Ago
Superior32 cm below3 cm above
Michigan-Huron30 cm below17 cm above
St. Clair13 cm above40 cm above
Erie41 cm above56 cm above
Ontario16 cm above22 cm above

 

Six-Month Forecast

For a graphical representation of recent and forecasted water levels on each of the Great Lakes and on Lake St. Clair, compared to their 1918–2010 period-of-record monthly averages and extreme levels, please refer to the December 2011 edition of the Canadian Hydrographic Service's monthly water levels bulletin.

Bulletin's Naming Convention

Each month, LEVELnews directs its readers to the Canadian Hydrographic Service's monthly water levels bulletin for the latest six-month water level forecast. For example, this month's issue points to the December 2011 edition of that bulletin. Contrary to what might be expected, the December 2011 date is not an error. The December 2011 edition of that bulletin is produced and posted on the Internet by the Canadian Hydrographic Service early in January 2012. The December 2011 date on the bulletin indicates that it includes recorded water level data up to, and including, December 2011.

It should also be noted that even though it is now 2012, the period of record used for comparison purposes in the bulletin and LEVELnews is still 1918–2010, and will likely remain so for a couple more months. The 2011 water level data needs to be verified and accepted as correct before the period-of-record statistics can be updated to 1918–2011.

Lake Erie–Niagara River Ice Boom

Each year since 1964, the New York Power Authority and Ontario Power Generation have installed the Lake Erie–Niagara River Ice Boom at the head of the Niagara River. The use of the ice boom is authorized by the International Joint Commission and is overseen by the Commission's International Niagara Board of Control.

Installation of the boom spans can begin on whichever comes first: December 16 or when the Lake Erie water temperature, as measured at the Buffalo Water Intake, falls to 4°C. With the Lake Erie water temperature at 6°C on December 14, installation of the ice boom's spans was planned to begin as permitted on December 16. However, strong winds and high wave conditions delayed the start of installation until December 17. Installation of the boom was completed on December 18. The water temperature at Buffalo remained above 4oC throughout the boom installation period.

 

December Precipitation over the Great Lakes*
Great Lakes Basin90%
Lake Superior62%
Lakes Michigan-Huron 86%
Lake Erie
(including Lake St. Clair)
145%
Lake Ontario91%

 

December Outflows from the Great Lakes*
Lake Superior76%
Lakes Michigan-Huron90%
Lake Erie117%
Lake Ontario114%

*As a percentage of the long-term December average.
Note: These figures are preliminary.

For more information:

Chuck Southam (Editor)
Boundary Water Issues Unit
MSC – Operations Ontario
Environment Canada
P.O. Box 5050
Burlington ON  L7R 4A6
Tel.: 905-336-4955
Fax: 905-336-8901
Email: water.levels@ec.gc.ca

David Fay
Great Lakes–St. Lawrence
Regulation Office
MSC – Operations Ontario
Environment Canada
111 Water Street East
Cornwall ON  K6H 6S2
Tel.: 613-938-5725