Study confirms decline in Great Lakes
Published January 24th, 2005
OTTAWA — Water levels in Lake Huron and Lake Michigan
have dropped by 80 centimetres since the 1800s — and will
continue to drop with major environmental costs unless
remedial action is taken, says a study released today.
Water levels of the "middle" Great Lakes have
declined because of dredging, gravel-mining and shoreline
alteration over the last 140 years, says the report commissioned
by the Georgian Bay Association, a citizens group.
Activists are calling for a moratorium on further dredging,
research aimed at finding corrective measures and firm
rejection of proposals to expand the St. Lawrence canal
to accommodate larger ships.
"Without implementation of compensation measures,
this drop represents an irreversible decline in the long-term
average lake level," says the study.
"This is very significant with potentially extensive
socio-economic and environmental implications."
Mary Muter of the association, which raised $200,000
to pay for the study, said wetlands around the area are
drying up with devastating effects for wildlife.
"Georgian Bay wetlands are the most ecologically
diverse, significant and pristine found anywhere on the
Great Lakes," she said in a teleconference today.
The study attributes the continuing decline in water
levels to erosion in the St. Clair River, at the bottom
of Lake Huron. The river is compared to the drain of a
bath tub — when the drain is larger, the water drains
Ironically, one factor in the deepening of the St. Clair
is shoreline protection built by property owners upstream
to prevent erosion of their waterfronts. This reduces
the supply of sand that is carried to the river and that
would help keep it shallow.
People living around the Great Lakes have seen the unpleasant
results of low water levels in the last decade, said Tim
Eder of the U.S. National Wildlife Association.
"Low water levels are serious problem for people
and wildlife. When water levels go down, impacts include
shorelines that dry up and expose mud flats instead of
"Ships must carry lighter loads. Recreational boaters
found that docks . . . were high and dry. Countless boaters
The International Joint Commission which manages Canada-U.S.
boundary waters is studying the report, said a spokesman.