GLIN==> U.S.-Canada Panel Releases St. Clair River Report

For Immediate Release:
Contact:   John Nevin 

Tuesday, December 15, 2009
202-256-1368

 

U.S.-Canada Panel finds that St. Clair River is Stable; Board sees no
need for Remedial Measures

 

Since 2007, a binational team of experts, with extensive public input,
has been investigating whether there are ongoing changes in the St.
Clair River that might be affecting water levels in the upper Great
Lakes.   In a report <http://www.iugls.org/>  released today, the
International Upper Great Lakes Study Board found:

*         There has been no significant erosion of the channel in the
upper reach of the St. Clair River bed since at least 2000.

*         Based on 15 different analyses, an increase in the river's
conveyance capacity accounts for 7 to 14 cm (2.8 to 5.5 inches) of the
decline in head difference between Lake Michigan-Huron and Lake Erie
from 1963 to 2006; however, this change is not ongoing and there has
been a slight decrease in conveyance capacity since 2000.

*         Climate is the main driver of lake level relationships over
time and accounts for 9 to 17 cm (3.5 to 6.7 inches) of the decline in
head difference. In particular, hydroclimatic change contributed to a
substantial decline in net water supplies to Lake Michigan-Huron in the
most recent decade.

Overall, the Study Board found that the difference in water levels
between Lake Michigan-Huron and Lake Erie (head difference) declined on
average by about 23 cm (9 inches) between 1963 and 2006.  They also
found that shifts in the earth's crust as it continues to adjust to the
retreat of glaciers account for 4 to 5 cm (1.6 to 2 inches) of the
decline in head difference with the apparent resulting decrease in water
levels being more pronounced in the Georgian Bay region of eastern Lake
Huron.  

 

As directed in its mandate, the Study Board also reviewed past proposed
remedial works and new innovative approaches to modifying flows in the
St. Clair River and identified a range of options that might be employed
if remediation were deemed necessary.  The Study recognizes that there
have been a number of dredging projects in the past and the governments
made commitments for remediation.  The implications of these past
dredging projects are beyond the scope of the Study.  The complete
scientific report
<http://pub.iugls.org/en/Other_Publications/IUGLS_Final_Report.pdf>  and
a summary for the public
<http://pub.iugls.org/en/Other_Publications/IUGLS_Summary_Report_EN.pdf>
are posted at:  www.iugls.org <http://www.iugls.org> .  The 34
scientific reports that form the foundation for the main report are also
available online.

 

Key Recommendations

Given that the change in conveyance capacity is not ongoing, is small
relative to the degree of scientific uncertainty associated with the
various analyses and data measurements and appears to be decreasing, the
Study Board did not recommend remedial measures in the St. Clair River
at this time.  The Board also recommended that the governments of Canada
and the U.S. undertake cooperative efforts to improve the monitoring and
analysis of Great Lakes water supplies and connecting channel flows.

 

Independent Peer Review

 Throughout the Study, both methodological plans and technical work
products including key chapters and the full draft report were reviewed
by independent experts chosen by the American Society of Civil Engineers
(ASCE Environmental and Water Resources Institute) and the Canadian
Water Resources Association.  These expert reviewers have given
generally positive ratings and provided many constructive
recommendations that have resulted in improvements to the final report,
ranging from the need for additional analysis to the need to better
quantify scientific uncertainty.  All reviews and Study Board responses
are available at the ASCE website, 
http://content.ewrinstitute.org/committees/IUGLS.cfm
<http://content.ewrinstitute.org/committees/IUGLS.cfm> . 

 

Public Input

A binational Public Interest Advisory Group (PIAG) with expertise from a
wide range of interests has provided advice to the Study Board on public
involvement and outreach issues.   The U.S. and Canadian co-chairs of
PIAG both serve on the Study Board, providing direct involvement by the
public in key decisions.  Since 2007, the Study has held 34 public
meetings hosted by PIAG members throughout the upper Great Lakes basin,
including 17 meetings during a 90-day consultation period following
release of a draft report on May 1, 2009.  

 

All public comments
<http://pub.iugls.org/en/Other_Publications/Public_Questions_and_Comment
s.pdf>  received by the August 1 deadline and Study Board responses are
posted on the Study website as well as a detailed report
<http://pub.iugls.org/en/Other_Publications/PIAG_report_exec_summary.pdf
>  on PIAG activities over the past two years, including a synthesis of
the public views provided during the consultation.  Generally, it
appeared that the public found that Study outcomes were acceptable with
respect to the mandate, resulted from an open and unbiased process and
reflected sound science.  However, it should be noted that many
commenters with interests in Georgian Bay disagreed with the Study's
recommendation against remediation.  The International Joint Commission
has announced it will hold public hearings regarding the report in 2010,
allowing the public ample time to review the report, related technical
studies and the independent peer reviews.  

 

What's next for the Study?

The examination of the St. Clair River is part of a broader evaluation
of the regulation of Lake Superior outflows that is expected to produce
recommendations in 2012 regarding improvements to the control orders for
the international compensating works and power dams on the St. Marys
River in Sault Ste. Marie.  The Study Board also recommends that this
phase of the Study examine whether mitigative measures in the St. Clair
River might be necessary based on its assessment of the potential future
impacts of climate change on upper Great Lakes levels.

 

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