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Summer vacation researching lakes
The Journal Gazette (8/25)
Steve Park, a seventh-grade science teacher from Riverview Middle School in Huntington, Ind. spent a portion of his summer on an Environmental Protection Agency research vessel.

Senators announce funding for University of Michigan project
WKZO - Washington, D.C. (8/25)
Senators Debbie Stabenow and Carl Levin say that a grant for the University of Michigan will help develop models to protect Lake Erie from the effects of algal blooms.

Residents get hands-on lesson about Maumee River conditions
WTVG 13 ABC - Toledo, OH (8/25)
More than two dozen people took a two-hour look at the Maumee River and nearby facilities that impact its condition. The tour, hosted by the Lake Erie Waterkeeper, was especially important this year because of the growing algae bloom in Lake Erie.

Save the River looks to boost its education program
TWC News - Syracuse, NY (8/20)
A volunteer for a non-profit dedicated to protecting the St. Lawrence River has published a book to benefit the cause.

Great Lakes Bay Regional Alliance aims to raise awareness of Bay City's schooner Appledore, other STEM teaching tools
MLive (8/20)
Great Lakes Bay Regional Alliance ambassadors and board members, joined Bay City, Mich. area educators and members of the media for a STEM excursion aboard the schooner Appledore IV.

Local teachers travel to study lakes
The Journal Gazette (8/4)
An Indiana high school teacher and his brother were among the group of educators who took part in a weeklong summer program at Michigan Technological University in Houghton, Mich., as part of the Great Lakes Teacher Institute.

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

4 | How levels and flows are measured

Water levels are measured and recorded at many locations around the Great Lakes and on their connecting channels.

Click to see larger image.The National Ocean Service of the National Oceanic and Atmospheric Administration (NOAA) presently operates 31 water level gages on the Great Lakes and 18 gages on the connecting channels. In Canada, the Canadian Hydrographic Service maintains 29 water level gages on the Great Lakes and 27 on the St. Lawrence River. Other agencies, including the U.S. Army Corps of Engineers, New York Power Authority and Ontario Power Generation, also operate recording gages at various locations on the lakes.

See also: Map of Great Lakes Water Level Gauging Stations

Great Lakes water levels are officially measured from the International Great Lakes Datum 1985 (IGLD 1985). This datum is referenced to sea level, as measured at Rimouski, Quebec, near the mouth of the St. Lawrence River. Because the crust of the earth in the Great Lakes region is continuously rising with respect to sea level, and the rate of movement is not uniform throughout the region, the IGLD must be updated every 25 to 30 years.

See also: FAQ about the International Great Lakes Datum

Click to see larger image.The rate of flow, or discharge, in a river or Great Lakes connecting channel is determined by measuring the channel depth and width, and the velocity of the flow. Measurements can be made by boat, from a bridge, or from a cableway strung across the river. With sufficient measurements of flow over a range of water levels, mathematical relationships can be developed between levels and discharges for various points along the connecting channels and the St. Lawrence River. These equations are essential to the coordination of outflow data, particularly related to hydroelectric power usage of Great Lakes waters.

Graphics: Water level gaging station; measuring outflows at the Niagara Cableway.

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