CONCLUSIONS 



The streamflow and precipitation data analyzed from Halfway and Miller Creek water- 

 sheds show no statistically significant change in streamflow patterns as a result of 

 contour trenching. This conclusion is based on 4 years of records after trenching and 

 12 years of records before trenching. The slight decrease in streamflow since trenching 

 is perhaps due to chance variation in the data or to a slight increase in consumptive 

 use due to a delay in streamflow from the trenched area. The possibility that any 

 change is due to trenching is further reduced by supplemental data that show no appreci- 

 able change in the distribution of moisture available as potential streamflow. Snow 

 distribution remains approximately the same, except for some on-site redistribution 

 (Doty 1970) . The consumptive use of soil moisture by vegetation has not shown appreci- 

 able change to date, although a trend similar to that reported by Bailey and Copeland 

 (1960) may be developing. 



The streamflow characteristics of the two drainages before and after trenching are 

 summarized in table 3. 



After an examination of streamflow regimen and watershed characteristics, such as 

 soil type and vegetation, it is concluded that contour trenching has not significantly 

 affected streamflow patterns of the Halfway Creek drainage. 



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