November 2012 photo shows white streaks on steel breakwall that shows the normal water level on Portage Lake at Onekama, Mich., which is connected by a channel to Lake Michigan. Levels across much of the Great Lakes are abnormally low.
The Associated Press
Two of the Great Lakes have hit their lowest water levels ever
recorded, the U.S. Army Corps of Engineers said Tuesday, capping more
than a decade of below-normal rain and snowfall and higher temperatures
that boost evaporation.
Measurements taken last month
show Lake Huron and Lake Michigan have reached their lowest ebb since
record keeping began in 1918, and the lakes could set additional records
over the next few months, the corps said. The lakes were 29 inches
below their long-term average and had declined 17 inches since January
2012.
The other Great Lakes, Superior, Erie and Ontario, were also well below average.
"We're in an extreme situation," said Keith Kompoltowicz, watershed hydrology chief for the corps district office in Detroit.
The
low water has caused heavy economic losses by forcing cargo ships to
carry lighter loads, leaving boat docks high and dry, and damaging
fish-spawning areas. And vegetation has sprung up in newly exposed
shoreline bottomlands, a turnoff for hotel customers who prefer sandy
beaches.
The corps' report came as shippers pleaded with
Congress for more money to dredge ever-shallower harbors and channels.
Shippers are taxed to support a harbor maintenance fund, but only about
half of the revenue is spent on dredging. The remainder is diverted to
the treasury for other purposes. Legislation to change that policy is
pending before Congress.
"Plunging water levels are
beyond anyone's control, but the dredging crisis is man-made," said
James Weakley, president of the Cleveland-based Lake Carriers'
Association.
Kompoltowicz said the Army corps might
reconsider a long-debated proposal to place structures in a river to
reduce the flow of water away from Lakes Huron and Lake Michigan, which
are connected.
Scientists say lake levels are cyclical
and controlled mostly by nature. They began a steep decline in the late
1990s and have usually lagged well below their historical averages since
then.
But studies have shown that Huron and Michigan
fell by 10 to 16 inches because of dredging over the years to deepen the
navigational channel in the St. Clair River, most recently in the
1960s. Dredging of the river, which is on the south end of Lake Huron,
accelerated the flow of water southward from the two lakes toward Lake
Erie and Lake Ontario, and eventually into the Atlantic Ocean.
Groups
representing shoreline property owners, primarily in Lake Huron's
Georgian Bay, have demanded action to slow the Lake Huron and Michigan
outflow to make up for losses that resulted from dredging, which they
contend are even greater than officials have acknowledged.
Although
the Army corps produced a list of water-slowing options in 1972,
including miniature dams and sills that resemble speed bumps along the
river bottom, nothing was done because the lakes were in a period of
above-average levels that lasted nearly three decades, Kompoltowicz
said.
The corps has congressional authorization to take
action but would need money for an updated study as a first step, he
said. The Detroit office is considering a funding request, but it would
have to compete with other projects nationwide and couldn't get into the
budget before 2015.
"It's no guarantee that we're going
to get it, especially in this budget climate," Kompoltowicz said. "But
there are serious impacts to navigation and shoreline property owners
from this extreme event. It's time to revisit this."
Scientists
and engineers convened by the International Joint Commission, a
U.S.-Canadian agency that deals with shared waterways, issued reports in
2009 and last year that did not endorse trying to regulate the Great
Lakes by placing structures at choke points such as the St. Clair River.
The commission has conducted public hearings and will issue a statement
in about a month, spokesman John Nevin said.
Roger
Gauthier, a retired staff hydrologist with the Army corps, said a series
of "speed bumps" could be put in the river at a reasonable cost within a
few years. Without such measures, he warned, it "would take years of
consistent rain" to return Lake Michigan and Lake Huron to normal.