Program script for Tuesday, September 04, 2001
By Kathleen Schmitt- Earthwatch Radio
A concrete barrier is no friend to a river.
Dams were once considered magnificent feats of engineering.
But the perspective on dams has changed, and by the end
of this year, nearly 40 of them will be removed from rivers
all over the United States.
Todd Ambs is the Executive Director of the River Alliance
of Wisconsin. His organization has been working to remove
three dams in the southern part of the state on the Baraboo
River. Two of the dams are gone already, and the third
is scheduled to be removed this fall.
Ambs says dams slow down river currents, block the migration
of fish, and flood valuable wildlife habitat.
"As I like to say, one of the worst things
that you can do to a river, short of pumping raw sewage
directly into it, is to dump a chunk of concrete into
it. And we knew that removing these dams would have a
tremendous beneficial impact on the riverine ecosystem.
What even we did not appreciate was just how significant
and how quickly the river would recover."
Before the first dam was removed from the Baraboo River,
the Wisconsin Department of Natural Resources examined
the reservoir behind it. There were 11 species of fish
in it, and the dominant one was carp. Ambs says that situation
"Eighteen months later, after the dam had been
removed, they found 24 species of fish, and the dominant
specie was smallmouth bass. Dissolved oxygen levels were
way up. Nutrient loading, which had been a real problem,
was way down. As we like to say, it really was proof positive
that if you remove the dam, the fish will come."
When the final dam is taken out, 120 miles of the Baraboo
River will again flow freely. Ambs says that might be
the longest stretch of river in the United States ever
restored by removal of a dam.
"Baraboo River Restoration Project: Removal of the Waterworks,
Oak Street and Linen Mill Dams," from River Alliance
Dams slated for removal in 2001 from American Rivers
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University of Wisconsin-Madison
Copyright 2001 University of Wisconsin Board of Regents