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MSU conference explores need for greater international cooperation to protect vital global watersheds
MLive (11/25)
A recent Michigan State University workshop focused on water rights and improving cross-border policies for the protection of the great waters of the world.

VU students testing area waters
The Northwest Indiana Times (11/21)
Students of Valparaiso University, Ind., were at Lake Michigan to work on water quality measurements for an Environmental Protection Agency education project.

Forest Hills students put surf boards to the test in Lake Michigan
MLive (11/20)
Surf’s up! Well at least it was for some lucky students from Forest Hills Public Schools on Thursday, Nov. 19. Twenty students from each of the district’s three high schools had an opportunity to surf 10- to 12-foot waves at Grand Haven State Park, Mich.

City says yes to dock sale
Traverse City Record-Eagle (11/3)
In Traverse City, Mich., commissioners agreed to sell the coal dock marina to a group of nonprofit organizations focused on Great Lakes history, education and environmental protection to expand use for nonprofits and construct new, modern facilities.

TVDSB high school students learn about importance of Great Lakes
St. Thomas Times-Journal (10/31)
Participants at the Lake Erie Student Conference spent the day in Port Stanley, Ont., taking demonstrations on water quality testing, commercial fishing, birds of prey and the threat of invasive species.

TEACH Calendar of Events
What's going on in your neighborhood this month? Meet other people and learn together at recreational and educational events! Our new dynamic calendar is updated daily with current educational events.
Water levels on the Great Lakes

table of contents
Three types of water level fluctuations
History repeating itself: Hydrographs illustrate historical levels
How levels and flows are measured
Effects of lake level fluctuations
References and more information

Water levels on the Great Lakes

Click to see larger image. Water levels are part of the ebb and flow of nature.

The difference between the amount of water coming into a lake and the amount going out is the determining factor in whether the water level will rise, fall or remain stable. When several months of above-average precipitation occur with cooler, cloudy conditions that cause less evaporation, the levels gradually rise. Likewise, prolonged periods of lower-than-average precipitation and warmer temperatures typically result in lowering of water levels.

The recent decline of Great Lakes' water levels, now at lows not seen since the mid-1960s, is due mostly to evaporation during the warmer-than-usual temperatures of the past three years, a series of mild winters, and below-average snowpack in the Lake Superior basin.

Because the major factors affecting the water supply to the lakes--precipitation, evaporation and runoff--cannot be controlled or accurately predicted for more than a few weeks into the future, the influence of man-made regulation of lake levels is very limited. Nature has most of the control, adding water through snow and rain, and taking it away through evaporation.

Graphic: Lake Superior's south shore, April 2000.

Detailed Map: The Great Lakes-St. Lawrence River system

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