SECTION 



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Streambed Disturbance 



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In Montana's dry climate, 

 streams usually lose xvater as 

 gravity pulls water into the 

 ground. The material making 

 up the streambed controls the 

 rate that water is lost from the 

 stream. Fine sediments often 

 seal a streambed and slozo the 

 loss of stream water If heavy 

 equipment or other activities 

 disturb the fine sediments, 

 water can seep into the aquifer 

 at a much higher rate. This 

 can cause an entire reach of 

 the stream to go underground 

 for a while. 



How We Impact the Streambed Seal 



• Operating heavy equipment in the stream 

 channel 



• Removing or disturbing channel bed 

 materials 



Placer mining, for example, impacts streambed 

 seals in both of these ways 



Effects of Our Impact 



• Increases water seepage into aquifer 



• Reduces water available for in-stream use 

 and downstream users 



• Increases water temperature in the summer 

 Lessening Our Impact 



• Operate heavy equipment in the stream 

 channel only when absolutely necessary 



• Use irrigation diversion alternatives that do 

 not require operating heavy equipment in 

 stream channels 



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