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<br />OOluJ7 <br /> <br />36.1--9 <br /> <br />WATER INFORMATION MANAGEMENT SYSTEM HANDBOOK <br /> <br />Example - Method E. In this example a request has been made for a special <br />use permit to construct a water diversion in several stream channels on <br />National Forest System lands for the purpose of hydro-power generation. <br />In evaluating the application the hydrologist determines that a potential <br />for adverse channel impacts exists. <br /> <br />The application is presented in early spring and a response is expected <br />within thirty days. Initial examination of maps, photos, and other <br />available data reveals that a gaging station is located in the general <br />vicinity of the streams of interest and is in all major respects <br />hydrologically similar to the points of interest. Several other stations <br />are found within a locale having the same hydrophysiographic <br />characteristics. Further, examination of aerial photo stereo-pairs <br />indicates the likelihood that the channels will not adjust their <br />dimensions in response to frequent flows. <br /> <br />In light of the purpose of quantification, the time frame and the nature <br />of the channels to be quantified, the hydrologist approaches the project <br />in the following manner: <br /> <br />1. The method of choice is Method E. <br /> <br />2. The nearby gaging station is identified as the representative <br />station. (Gander Creek will be used for illustrative purposes.) <br /> <br />3. All of the stations listed in exhibit 1, rows a-I are suitable <br />stations. <br /> <br />4. Watershed area is the watershed characteristics which best <br />correlates with bankfull discharge. <br /> <br />5. To the extent possible bankfull discharge and bankfull discharge <br />channel top width will be determined through field measurements at gaging <br />stations. <br /> <br />6. Where unable to measure discharge and width these data items will <br />be secured using bankfull stage indicators, station stage-discharge <br />relations, and surveyor's level and stadia techniques. <br /> <br />7. Bankfull stage channel top width values will be an average of at <br />least three measurments in a reach. <br /> <br />8. Watershed area will be determined from USGS 7 1/2 minute <br />(1:24000) quadrangles. <br /> <br />Following is the stepwise analysis: <br />Step I - The needed data are found in exhibit 1. <br /> <br />ID No.3 <br />8/28/37 <br />