Application of the Montana Nonpoint Source Stream Reach Assessment 



Table E-2: Summary of Management Activities as Actual or 

 Potential Sources of Stream Problems* 



Percentages based on the number of reaches (out of 75 managed reaches) where the 

 surveyor could tie an activity directly to a stream problem or was confident that the 

 activity would be a problem in the near future. 



impaired reaches were primarily affected by 

 natural erosion and bank or channel instability. 



Comparison of impairment ratings, by 

 stream, to activity values derived from Sequoia 

 (Module H) and UpY (Module J) revealed a 

 non-significant correlation. 



We compared modified impairment ratings 

 using a combination of Bank Stability, Sub- 

 strate Composition, Channel Stability, and 

 Channel Modifiers to the Rl Channel Stability 



Siuvey (CSR — Module J) results. Compari- 

 sons were made on eight corresponding stream 

 reaches. Correlation between these methods 

 was significant, but negative (z = -2.23). High 

 CSR values correspond to poor channel stabil- 

 ity. High assessment values indicate low im- 

 pairment. 



For corresponding reaches, we compared 

 the Substrate Composition category from the 

 assessment procedure to the percentage of fine 



Flathead Basin Cooperative Program Final Report 



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