LEVELnews
Great Lakes–St. Lawrence River Water Levels
Volume 21, Number 8
8 August 2013
Recent Conditions and Upcoming Board of Control Events
Very wet conditions prevailed over the lakes Superior and Erie basins in July. More moderate conditions returned to Lakes Michigan-Huron, while wet conditions continued on Lake Ontario. Downstream of the Great Lakes, Montreal Harbour levels slid below average during early July.
- A very wet May followed by a wet June and a very wet July, combined with below-average outflows, resulted in Lake Superior’s level rising by 12 cm during July - three times its 1918–2012 period-of-record average rise of 4 cm during the month.
- More moderate conditions returned to Lake Michigan–Huron, causing it to rise by 1 cm during July. On average over the 1918–2012 period of record, Lake Michigan–Huron has started and finished July at the same level.
- Conditions were very wet over the Lake Erie basin during July. As a result, the level of Lake Erie increased by 2 cm during July instead of falling as it typically does during the month. On average, the level of Lake Erie has fallen by 5 cm during July.
- On Lake Ontario, slightly wetter-than-average conditions resulted in the lake’s level falling by 8 cm during July, 1 cm less than its average July decline of 9 cm.
- The monthly mean level at Montreal Harbour was 19 cm below average during July, but 93 cm higher than July’s level last year.
| Lake | Compared to Monthly Average (1918–2012) | Compared to One Year Ago |
|---|---|---|
| Superior | 13 cm below | 7 cm above |
| Michigan–Huron | 48 cm below | 5 cm above |
| St. Clair | 8 cm below | 16 cm above |
| Erie | 4 cm above | 21 cm above |
| Ontario | 15 cm above | 35 cm above |
| Lake | Compared to Beginning-of-Month Average (1918–2012) | Compared to One Year Ago |
|---|---|---|
| Superior | 8 cm below | 14 cm above |
| Michigan–Huron | 47 cm below | 7 cm above |
| St. Clair | 11 cm below | 15 cm above |
| Erie | 6 cm above | 26 cm above |
| Ontario | 13 cm above | 36 cm above |
Water Level Forecast
For a graphical representation of recent and forecasted water levels on each of the Great Lakes, Lake St. Clair and Montreal Harbour compared to their respective period-of-record monthly averages and extreme levels please refer to the July 2013 edition of the Canadian Hydrographic Service’s monthly water levels bulletin.
You're Invited
The three International Joint Commission (IJC) Great Lakes Boards of Control are holding public information events in August and September and you’re invited.
The International Lake Superior Board of Control is hosting a teleconference with the public during the afternoon of Wednesday, August 21, 2013. For detailed information about the teleconference and to download the meeting materials, please visit the Board’s website. You can also view the presentation slides via a webinar. Details on joining the webinar are also found on the Board website.
The International Niagara and the International St. Lawrence River Boards of Control will be holding public meetings during the evenings of Thursday, September 19, 2013 and Tuesday, September 24, 2013, respectively. Both boards are planning to provide telephone or on-line options for persons unable to attend their meetings in person. Please check next month’s edition of LEVELnews for additional information about these two meetings.
| Lake | % |
|---|---|
| Great Lakes Basin | 125% |
| Lake Superior | 160% |
| Lake Michigan–Huron | 100% |
| Lake Erie (including Lake St. Clair) | 149% |
| Lake Ontario | 108% |
| Lake | % |
|---|---|
| Lake Superior | 96% |
| Lake Michigan–Huron | 87% |
| Lake Erie | 109% |
| Lake Ontario | 101% |
*As a percentage of the long-term July 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
Rob Caldwell
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: