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Channel Straightening 



Streams that flow through steep, 

 narrow valleys run relatively fast and 

 straight. But once a stream moves into 

 less steep and less confining land 

 forms, it slozvs and begins to curve and 

 meander. When the natural sinuosity 

 of a stream is altered, the stream 

 becomes steeper and its flow increases 

 in energy. The stream reacts to these 

 changes by making adjustments. 



Effects of Our Impact 



• Eliminates meanders and shortens 

 stream length, which increases 

 slope and reduces natural energy 

 dissipation 



• Increases velocity of water, which 

 increases erosion downstream 



• Increases flood intensity 



— Speeds movement of peak flows 

 — Eliminates storage capacity of 

 stream 



• Decreases channel stability and 

 increases channel migration as the 

 channel attempts to come to a new 

 equilibrium; this also increases 

 problems upstream and 

 downstream 



Why Streams are Straightened 



• To reduce the number of highway and 

 railroad crossings 



• To develop land more easily along 

 streams 



• To control overbank flows 



• To protect property by eliminating 

 channel migration 



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Lessening Our Impact 



Stream managers rarely recommend straight- 

 ening channels. Instead, they suggest these 

 alternatives: 



• Plan roads and other developments 

 away from streamside areas 



• Control upstream sediment sources 

 to reduce downstream instability 



• Stabilize channel banks 



If your stream is already 

 straightened, consult a stream 

 management specialist about 

 restoring straightened sections 

 to their original channel shape 

 and pattern. 



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