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■ Unhealthy Stream Types 



Common in Montana 



Some Indicators of Unstable Stream Channels 



• channel widening 



• unvegetated, eroding stream banks 



• channel downcutting 



• increased silt/clay on channel bottom _ 



• inability to overflow banks during spring runoff 



• increase or decrease in water supply 



• increase or decrease in sediment supply 



Wide, 



Shallow 



Stream 



• sinuous 



• slope <4% 



flood- 

 prone 

 area 



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^^ 



f^; 



^ 



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^■bankfuU stage 



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prone 

 area 



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treatn 



■ than 2% 

 multiple shifting channels 

 herfvy sediment load 



erodes laterally 

 wide, shallow 

 little aquatic habitat 



Some braided streams occur naturally, such as in a glacial 

 headwater environment, but they most often result from human 

 activities that contribute excessive sediment to the stream. 



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