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Aquatic and Riparian Resources <br />lead to a loagterm reduction in effects from wildfue. With the exception of fire, effects from full <br />implementation budget levels are expected to be equal or greater than experienced levels. <br />EXISTING, DIRECT, AND INDIRECT EFFECTS <br />Surface water, groundwater, floodplains, riparian areas, and aquatic habitats for indicator species <br />and other organisms are ail closely related. Discussion of effects on these resources will be dealt <br />with together since the pathways of effects that influence alI of them are similar. When they are <br />impacted differently, it will be specifically noted and described. <br />Watershed conservation practices, and Forest Plan standards and guidelines, prescribe extensive <br />measures to protect soil, riparian, and aquatic resources. If all applicable measures are <br />implemented and if they aze effective, adverse effects to these resources from manaQement <br />activities should be minimized. However, as the levels of activity increase, the risk that <br />conservation practices will not be implemented or will not be cumulatively effective increases. <br />Consequendy, alternatives which propose greater levels of activity for various resources <br />generally pose greater risk to aquatic and riparian resources. <br /> <br />? For each of the resource azeas described below, the environmental consequences for aquatic <br />resources aze compared by alternative, based on relative indices of disturbance for each type of <br />? activity.. <br />EFFECTS OF VEGETATION MANAGEMENT ON WATER YIELD ? <br />? Water yield increases from vegetation management are of great interest to many of those who <br />depend upon water oriQinating from the Forest. As noted in the Affected Environment section, <br />? the demand for water is greater than the supply. The Forest provides water not only for <br />municipal and aQricultural use but also contributes flow for endanaered species as far <br />downstream as the Platte River in I\Tebraska. <br />? Streamflow from forested watersheds is a function of total precipitation and losses due to <br />evapotranspiration and aroundwater storaQe. Trees in the watershed affect streamflow by <br />? transpiring water, intercepting snow or rain which may be evaporated or sublimated back into the <br />atmosphere, and by modifying the understory's evapotranspiration (Kaufmann et al. 1987). <br />Removal of trees can increase water available for streamflow by reducing evapotranspiration and <br />? increasing snowpack accumulation into the openings (Alexander et al. 1985). Consequently, the <br />two major forest management activities which influence water yield are timber harvest and f re. <br />? The increase in water yield caused by timber harvest or fire is largely deternuned by the amount <br />of precipitation which occurs on a site. Thus, treatment in spruce-fir yields the greatest increases <br />per unit area, because spruce-fir typically occupy the wetter sites. Increases are smaller for <br />? treatment of lodgepole pine and smallest for ponderosa pine. Increases in sueamflow from <br />vegetation management are not permanent. As an area is restocked and the crees grow, water that <br />was available for streamflow is slowly redirected back to evapotranspiration. Research at the ? <br />? <br />Chapter Three • 125 <br />.?