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<br />o <br />c,:. <br />I>- <br />1......\ <br />CO <br />W <br /> <br />Elevation data will be obtained by stretehing a marked cable across the river between <br />anchor points for each transect and measuring the channel depth relative to a local bench mark. <br />River depths will be measured at 5 to lOft increments, depending on location, length of cross- <br />section and change in elevation. Substrate type at the point of depth measurement will be <br />characterized as sand or graveVcobble and recorded. The full-width flood plain surveys will be <br />completed with a total station outside the active channel at points representing changes in grade <br />(e.g. tops of hills, edges of channels, toes of banks). <br /> <br />The survey data will be plotted using Autoead and the average and maximum change in <br />channel depth since the preceding survey will be eomputed. Substrate attributes also will be noted <br />in the files. Percent composition of substrate by type will be computed for each measurement. <br /> <br />Data will be summarized and the results reported annually. Annual reports will contain <br />eross-section plots, change in average eross-seetion elevation from pre- to post- runoff and from <br />the previous year and percent substrate composition noted. Every 5 years the flow/morphology <br />relationships will be analyzed for verification or adjustment. <br /> <br />Cobble Bar Characterization <br /> <br />Maintenance of cobble bars with open interstitial space has been determined to be <br />important for spawning by Colorado pikeminnow. Four locations (R..\I1173.7, 168.4, 132.0, and <br />131.0) have been identified in the San Juan River as having attributes suitable for spawning. <br />These locations have been monitored for change in shape, particle size composition and depth of <br />open interstitial space. <br /> <br />Topographic surveys will be completed annually for each of these cobble bars, utilizing <br />total station or GPS survey equipment with control provided by the established bench marks at <br />each loeation. Surveys will be completed as soon as practical after spring runoff, usually during <br />late July or early August. The same area will be surveyed each year to enable eomparisons among <br />years. <br /> <br />9 <br /> <br />Draft Long Tcnn Monitoring Plan - SJRlP Biology Commincc <br />