Laserfiche WebLink
<br />(l~J?O'!G <br />dt 1..,('1 , <br /> <br />. <br /> <br />. <br /> <br />increased flow during the high water season is either wasted or causes <br /> <br />damage. Seasonal distribution of flow is especially critical in the deep <br /> <br />snowpack country of the western states. Increases in the spring peak flows <br /> <br />are much less valuable than increases to summer and fall flow, Treatments <br /> <br />tested so far have increased peak flows with slight or no effect on late <br /> <br />season runoff. <br /> <br />Another question concerning usable yield is the application of test <br /> <br />watershed results to larger basins. How far downstream will treatment effects <br /> <br />reach? There isn't any simple answer to that question because, in addition, <br /> <br />to natural factors causing channel losses, pumping and diversions may also <br /> <br />take a toll. The only way to answer chis question is from examination of <br /> <br />specific watersheds and channels. <br /> <br />Erosion control.--There is still much to be learned about the use of <br /> <br />vegetation for erosion control. Because of difficulties and uncertainties <br /> <br />in establishing plant cover it has been necessary to use expensive check dams) <br /> <br />contour trenches and terraces. This is especially true in the more arid parts <br /> <br />of the West. The general availability of earth~moving equipment has encouraged <br /> <br />an increasing reliance on such mechanical measures. Dams, furrows, spreaders, <br /> <br />and terraces require maintenance until their job is taken over by vegetation. <br /> <br />Past experience teaches that this maintenance is too often neglected. However, <br /> <br />the trend towards using machinery instead of vegetation will continue until <br /> <br />reliable methods for plant esteblishment are proven. <br /> <br />Increasing attention is directed towards learning more about how <br /> <br />plants can be used to control erosion. The properties of plant materials <br /> <br />- 9 - <br /> <br />