[Date Prev][Date Next][Date Index]

GLIN==> Open Letter about the International Upper Great Lakes Study

A five year International Upper Great Lakes Study (IUGLS) was officially
launched by the International Joint Commission (IJC) in March 2007. The
IJC has appointed leading U.S. and Canadian experts from inside and
outside of government to conduct an independent, peer-reviewed
investigation of factors affecting water levels and flows on lakes
Superior, Huron, Michigan and Erie. The main objectives of this study
are to review the regulation of Lake Superior outflows and to examine
the physical processes and possible ongoing St Clair River changes and
their impacts on the water levels of Lake Michigan and Huron. The IJC
directed the Study Board to complete the St Clair River portion of the
Study by early 2010. 


 A recent estimate by the Georgian Bay Association (GBA) indicated that
the volume of the river outflow may have increased by as much as 2.5
billion gallons per day, or about 2 percent of the flow of the St Clair
River, as a result of dredging. These impacts are greater than those
previously reported by the IJC. The GBA is requesting that action be
taken immediately to address this issue. IUGLS will be assessing all the
potential contributing factors to the changes in water level in order to
ensure that informed decisions can be made. Studies have been initiated,
hydrographic surveys are being conducted, hydrometric stations are
currently being installed in order to provide us with the information
needed to address this issue.


Climate change and variability, hydrology, glacial isostatic adjustment,
and streambed erosion are a number of key factors affecting the water
levels that need to be assessed in a comprehensive manner to determine
their relative importance to the lowering of the lake levels. The IUGLS
will examine the changes that have occurred both naturally and through
man-made factors over the last few decades in the St Clair River. A
report addressing changes in the flow regime of the St. Clair River and
the factors affecting water levels will be provided to the IJC by early
2010. Depending on the nature and extent of physical changes in the St.
Clair River, and their potential impacts on water levels and flows, the
study would explore potential remediation options. In the interim, the
Study Board will report every six months on its work and any preliminary


The Study Board recognizes that the levels of the Upper Great Lakes are
declining to a significant extent, however remedial action cannot be
considered without a full scientific assessment of all the factors
involved in the hydrological cycle and their relative impacts both
upstream and downstream of the St. Clair connecting channel.
Hydrological shifts are well documented on the Great Lakes and this must
also to be taken into account in determining the need for remedial
action. Finally, any structural changes in the St. Clair River will
require agreement by both the U.S. and Canadian governments.




Ted R. Yuzyk                                                   Eugene Z.

Canadian Co-Chair, IUGLS                            United States
Co-Chair, IUGLS