LEVELnews
Great Lakes–St. Lawrence River Water Levels
Volume 20, Number 3
16 March 2012
Water Levels Remain Higher than Last Year as Levels Decline
The water levels for the month of February saw slightly greater declines--or, in the case of Lake Ontario, a smaller rise--than what is typical for the month. However, on all the Great Lakes, they remained higher than what was reported for February 2011.
- Lake Superior: Below-average supplies for Superior were offset by below-average outflows, causing that lake's level to fall by 6 cm this February. That drop is 1 cm more than Superior's average February decline of 5 cm.
- Lakes Michigan–Huron: The level fell by 4 cm in February, which is 4 cm more than the historical average for a month when Michigan–Huron levels typically do not change. This drop is attributed to below-average supplies and outflows that were slightly above the monthly average.
- Lake Erie: The level on Erie dropped by a total of 4 cm compared to a typical rise of 2 cm in February. Although Erie had above-average supplies for the month, the lake's outflow was significantly above average, which led to the decline.
- Lake Ontario: The one Great Lake where the level increased. Ontario saw a 2 cm rise for February, which is 1 cm less than the average rise of 3 cm.
| Lake | Compared to Monthly Average (1918–2011) | Compared to One Year Ago |
|---|---|---|
| Superior | 33 cm below | 1 cm above |
| Michigan-Huron | 33 cm below | 18 cm above |
| St. Clair | 49 cm above | 21 cm above |
| Erie | 39 cm above | 62 cm above |
| Ontario | 39 cm above | 58 cm above |
| Lake | Compared to Beginning-of-Month Average (1918–2011) | Compared to One Year Ago |
|---|---|---|
| Superior | 32 cm below | 2 cm above |
| Michigan-Huron | 34 cm below | 16 cm above |
| St. Clair | 19 cm above | 26 cm above |
| Erie | 36 cm above | 53 cm above |
| Ontario | 36 cm above | 57 cm above |
March Forecast
With average water supply conditions, the level of Lake Superior is expected to continue to fall slightly in March, as is typical at this time of year. The levels of lakes Michigan–Huron, St. Clair, Erie and Ontario are all expected to rise in March from their beginning-of-March levels.
Six-Month Forecast
The February 2012 edition of the Canadian Hydrographic Service's monthly water level bulletin will be posted during March. It contains the forecasted range of water levels on each of the lakes for March through August 2012. Based on the latest six-month forecast, water levels on lakes Superior and Michigan–Huron will most likely remain below average throughout the spring and summer and for a potentially longer period of time. On the other hand, it appears that lakes Erie and Ontario will likely remain above average unless dry conditions are experienced. However, since weather and corresponding water-supply conditions can change significantly from one month to the next, it is important to check the bulletin at the beginning of each month for the latest water level conditions and forecast.
Lake Erie–Niagara River Ice Boom
Except for thin ice at times in some protected bays and shallow inlets, Lake Erie remained virtually free of ice for the winter of 2011–2012. As a result, removal of the Lake Erie–Niagara River Ice Boom began on February 28, which is the earliest removal of the boom on record. Forecasts for continued warm weather indicated that it is unlikely the boom will be needed to stabilize ice for the rest of the winter season. Additionally, ice-free conditions can result in breakages of the boom cables under high wind conditions, an outcome which had occurred four times this year. The earliest previous ice boom opening was on March 5, 1998, and the latest was on May 3, 1971.
| Great Lakes Basin | 75% |
|---|---|
| Lake Superior | 78% |
| Lakes Michigan-Huron | 77% |
| Lake Erie (including Lake St. Clair) | 82% |
| Lake Ontario | 58% |
| Lake Superior | 83% |
|---|---|
| Lakes Michigan-Huron | 105% |
| Lake Erie | 145% |
| Lake Ontario | 121% |
*As a percentage of the long-term February 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
- Date Modified: