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Stream Channelization: 
Invitation to Ecological Poverty 
by GARY C. THOMAS 
Illinois Department of Conservation 
“A RIVER 1s more than an amenity—it 1s a treasure.” Vhese words were 
spoken by Supreme Court Justice Oliver Wendell Holmes years ago. Did 
he speak to unhearing ears? 
A recent survey completed by the Illinois Department of Conserva- 
tion revealed that there are 8,129.94 miles of channelized waterways 
within the state. This figure is broken down into 3,123.6 miles of channel- 
ized natural streams, and 5,006.23 miles of man-made ditches and canals 
for drainage purposes (not including the Hennepin Canal). This does not 
take into account those portions of the Illinois and Mississippi Rivers 
which have been channelized. 
The survey was made by district fishery biologists of the Department 
during the winter of 1971-72. Until completion of this survey there was 
no known record of the total miles of channelized streams and ditches. 
“More and more people are becoming concerned about the alteration 
of streams and flood plains,” says William J. Harth, superintendent of 
fisheries in the Department of Conservation. “Such alteration usually takes 
the form of stream channelization, a practice which some of its advocates 
have the effrontery to euphemize as ‘stream channel improvement’.” 
CHANNELIZATION TURNS a meandering stream into a ditch. 
The practice usually includes straightening the natural meanders, clear- 
ing the banks and widening and deepening the channel. In some instances 
the spoil taken from the streams is spread along sides of the channel, or 
used to construct dikes and levees. 
“These changes have far-reaching and ecological effects, some of which 
may be disastrous,” Harth stated. “The effects of channelization will vary 
from watershed to watershed, depending on the quantity and quality of 
the natural resources in the local area and on the objectives and extent 
of the individual project.” 
Degrading effects of channelization were spelled out in a 1971 testi- 
mony statement by then-Director Henry N. Barkhausen of the Conserva- 
tion Department before the Congressional House sub-committee on Water 
Resources. 
THERE ARE THREE chief stated purposes for channelization. 
They are: 
(1) Navigation; to falicitate the movement of freight by water. It is 
usually limited to the larger streams, but sometimes smaller streams, like 
the Kaskaskia, are channeled for this purpose. 
