4 T HE AU DUB ON Bal Ea 
(2) Flood control; to protect from damage farms, factories and homes 
located on the flood plain. To accomplish this, the excess water is moved 
downstream as rapidly as possible. This, however, tends to flood the 
areas lying below the channelized portion of the stream. Streams of all 
sizes are involved, although generally the larger the stream the greater the 
danger of flood and the more extensive the work proposed. 
(3) Increase arable land. Although seldom stated nowadays, this was 
the principal purpose of much of the earliest channelization and is still a 
primary purpose in some areas. The validity of this purpose 1s question- 
able in a time of agricultural surpluses. It applies to streams of all sizes, 
but especially to smaller streams. More easily accomplished and economi- 
cally feasible, channelization for this purpose has already been done in the 
majority of intensively-cultivated areas. 
‘PROJECT LEADER on the stream channelization survey was Al 
Lopinot, Harth’s assistant. Lopinot’s criticism on channelization is that 
“it is planned and carried out with little consideration given to the nat- 
ural environment. Existing and potential recreational areas are defaced, 
fish and wildlife habitat is altered or destroyed, bottomland timber is re- 
moved and natural beauty is marred. 
“Many more miles of stream are destroyed than is indicated by the 
miles of ditch created,” said Lopinot. “A river meandering over a wide 
flood plain may be reduced to a straight ditch half or third as long as the 
original stream.” 
A ditch has no aesthetic appeal. However, more than aesthetics are 
involved. When a stream goes, many desirable features of the environment 
go with it. 
A stream is more than a waterway; it is the focus of the ecology of a 
watershed. Within the stream, invertebrate animals, vital elements in the 
food chain of fish, are dependent upon a stable substrate and protection 
from current. 
Fish food production takes place chiefly in riffes and accumulations 
of debris which are not permitted to exist in a drainage ditch. Ditches 
seldom have the specialized conditions the native stream fish species re- 
quire for successful spawning, hatching and rearing of young. Cover, which 
the fish require for protection from persistent current, especially during 
floods, is eliminated in a channelized ditch. 
Likewise, when dry weather occurs, the stream flow becomes low and 
water temperatures rise. There are no deep pools in a channelized stream 
to protect the fish. 
A NORTH CAROLINA STUDY involving 23 channelized streams 
showed that 90 percent (by weight or numbers) of the game fish were 
lost as a result of this practice. After a 40-year period no appreciable 
improvement had occurred. Other states conducting similar tests show 
less than a 10 percent recovery after 75 years of channelization. 
