Channel Entrenchment 



Entrenched channels are deep 

 ivith high banks. Entrenched 

 channels are most frequently 

 found in highly erodible 

 terrain. Changes in a channel's 

 hydrology, sediment supply, or 

 erosive energy can cause 

 entrenchment, which is also 

 called dozvncutting. 



What Causes Entrenchment? 



• Straightening or shortening a channel 



• Decreasing sediment supply, such as by trapping 

 sediments in upstream reservoirs 



• Increasing channel's water supply 



Effects of Entrenchment 



• Lowers level of local water table to new stream 

 elevation, which: 



— Changes streamside plants and affects fish 



habitat and stream flow 

 — Impacts irrigation diversion and 



groundwater wells 



Eliminates access to the floodplain, which 

 increases stream energy and bank erosion 



Reduces aesthetic values and recreational uses 



Reduces property value 



May increase water supply to a channel 



Lessening the Impact 



• Prevent downcutting by protecting 

 channel and banks from erosion, 

 and by maintaining healthy 

 vegetation along stream banks 



• As soon as you notice downcutting, 

 consult a stream management 

 specialist for help 



• Conduct a stream inventory or tour 

 the upper watershed to identify 

 potential problems 





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