For more than one hundred years, man has made changes to rivers and lakes. Locks, dams, and redirecting waterways has raised water levels and increased river flows. One effect has been the near disappearance of islands that once provided habitat for fish, plants, and birds. Some groups are trying to rebuild those islands. But the concept of a man-made island is not universally accepted. The Great Lakes Radio Consortium’s Jonathan Ahl reports:
For more than one hundred years, man has made changes to rivers and lakes. Locks, dams,
and redirecting waterways has raised water levels and increased river flows. One effect
has been the near disappearance of islands that once provided habitat for fish, plants, and
birds. Some groups are trying to rebuild those islands. But the concept of a manmade
island is not universally accepted. The Great Lakes Radio Consortium’s Jonathan Ahl
Jim Baldwin is driving his small boat along an island in the Illinois River, the body of
water that connects the Great Lakes to the Mississippi River. He is an environmentalist
that has been watching this portion of the river for years, and likes what he sees. He’s retired now,
and spends most of his time either at his cabin on the riverfront just north of Peoria, Illinois
or working with environmental groups looking to preserve rivers and streams. These
islands are not natural. The Army Corps of Engineers made them ten years ago. Baldwin
says since then, it’s not uncommon for him to take his boat out and see fifty to a hundred
“Everybody tells me that until this island was built, they never even stopped here. Now
some of them stay year round.”
The Corps built the islands by dredging silt and sediment that had been clogging nearby
portions of the river. The theory is the manmade islands would provide a buffer from the
river flow, and create an area of deep water that could provide habitat for sport fish. It
would also provide a feeding area for migrating birds.
John Marlin is a researcher with the Illinois Department of Natural Resources. He says the
program has been a success.
“The islands stop the large waves that come across the lake and there is a calm area behind
the islands the waterfowl seem to appreciate. Also, the birds such as pelicans and alot of the wading birds are using
the islands as resting areas.”
Marlin says the islands are growing thick vegetation, and the soil dredged from the river
has proven to be free of any pollutants that are present in some river sediments.
But not all environmentalists sing the praises of manmade islands. Some believe these
new islands will suffer the same fate of the natural islands that are now gone.
Tom Edwards is the head of River Rescue, an environmental group focusing on rivers. He
says the man made islands are only a temporary fix:
“The islands are an illusion. All of the wonderful that they say are going to result from the islands are not going to result. We have 113 islands in the river right now, and it hasn’t
resulted from a single one of them. So let’s learn from what’s here right now. So they are
going to dig the water deeper around these islands and hope that’s going create deep water.
It will be very temporary. Deep water amounts to a silt trap.”
Edwards says it is just a matter of time until the sediment fills up the deep water areas created by the manmade islands. He says until there are significant changes in land-use policy that keep sediment from entering rivers, manmade islands will only be a quick fix.
But river activist Jim Baldwin says many states and local governments are starting to adopt
land use policies that will keep sediment out of the Midwest Rivers and streams. He also
says using dredged materials to create the islands will help alleviate the problem. He says most importantly, the manmade islands are getting the job done.
“It does two things. Number one is it provides the deep water that we need for fisheries.
The island itself will grow trees and habitats for all kinds of birds. It will do that. That’s what it’s all based on is those two things.”
While the debate over man made islands continues, the Army Corps of Engineers is proposing to build two more islands on the Illinois River in the coming years.
For the Great Lakes Radio Consortium, I’m Jonathan Ahl.