Mason City Globe Gazette, IA
08-30-06
Clear Lake restoration sets a world standard
By DICK JOHNSON, Of The Globe Gazette
CLEAR LAKE — Clear Lake is getting healthier and the world is taking note,
according to John Downing, a professor in the Department of Ecology,
Evolution and Organismal Biology at Iowa State University.
The Clear Lake Enhancement and Restoration (CLEAR) project has set the
standard for lake restoration in Iowa and its ideals will help people worldwide
deal with water quality problems, he said in a telephone interview.
Dramatic changes in the adjoining Ventura Marsh after a test removal of carp in
2000 was the cover story of the January 2004 issue of Hydrobiologia, The
International Journal of Aquatic Sciences.
“It’s a domino effect,” Downing said. “It’s had a wide-ranging influence.
Congratulations to those who work on the Clear Lake project. It really is setting a
standard for how these things get done in the state.”
Downing was hired by the Department of Natural Resources to write a diagnostic
and feasibility study and make recommendations on the main restoration plan
created by ISU.
Reducing carp populations in the marsh will require continuous management, so
he recommended building a pumping station to allow better water level control
over the marsh, and a fish trap structure. These activities will allow vegetation
back into the marsh (carp stir up sediment, which prevents light from penetrating
and aquatic vegetation from growing). Construction should begin in late fall next
year.
He also recommended dredging the “little lake” on Clear Lake’s west end, which
has filled in the most over the years it has been affected by humans.
The plan is to build a dredging containment site starting this fall and for dredging
to begin in the spring of 2008, said CLEAR project director David Knoll.
“We’re excited about the progress we’re making, especially with the watershed
improvements that have already been completed,” Knoll said. “We still have a
long ways to go, but all these activities working together should bring us to the
water quality improvements that we’re striving for.”
Downing also credits responsive politicians (this spring the Iowa Legislature
approved a budget plan that includes $4 million for restoration, including
dredging), and dedicated workers from state agencies.
He said tangible improvements in water quality have been made due to changes
made in the Clear Lake watershed. Nutrient levels have dropped since an initial
study made between 1998 and 2000.
After 100 years of nutrient input and landscape change, final improvements will
take a while — up to 30 years. But people should start seeing improvements
within a few years of dredging, Downing said.
Among other things, restoration will improve fish habitat, water quality and
bacteria levels.
“The actions of everybody are important,” Downing said, “and this is the time to
redouble our efforts to make sure that things are good and positive for the lake.
“Great things are happening in Clear Lake,” he added. “If all goes as predicted,
it’ll become healthier and healthier every year.”
Reach Dick Johnson at 421-0556 or dick.johnson@globegazette.com.