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Statement of Daniel P. Christenson 

 9 March 1994 

 page four 



accelerated run-off of snow-melt and rain and desiccation of 



soils from exposure to sunlight. This results in higher than 



normal stream flows during peak run-off periods and reduced flows 



during minimum base-flow periods. The higher flows cause stream 



bank erosion and stream sedimentation and reduced water quality. 



Base-flow is a critical element of a healthy stream ecosystem 



and a major limiting factor in trout production. This base-flow 



is dependent upon stored ground-water in order to persist 



throughout the dry summer season. Vegetation removal results in 



accelerated run-off and desiccation of soils, both of which 



reduce ground-water storage and thus negatively impact stream 



ecosystems . 



The greatest dirfect impacts to stream habitats are from 



cattle grazing, which damages or destroys riparian vegetation, 



tramples stream banks, and degrades water quality. Riparian 



vegetation such as willows and grasses stabilize stream banks and 



provide cooling shade, provide protective cover for trout and 



other aquatic organisms, provide habitat for some trout food 



organisms and benefit mamy other wildlife species. Damage to 



riparian vegetation by cattle alters stream ecosystems and 



degrades aquatic habitat values. Trampling of banks by cattle 



causes alterations to stream channel conformation which reduces 



the amount of protective cover for trout. Cattle contribute to 



water quality degradation through soil disturbance and subsequent 



erosion which results in the introduction of sand and silt to 



