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Table 4. Current velocity in meters/sec, measured November 15 and 16, 1994, and observed <br />~~ substrate size distribution at each sample location. <br />• <br />Sl[e Me n~locity ThalweE Velocirv S~bctrate S'~e Dictrib ~ ion <br />US 0.41 0.72 100% boulders <br />U4 0.48 0.73 50% boulders, 45% cobble, 5% gravel <br />U3 0.51 0.61 70% boulders, 25% cobble, 5% gravel <br />U2 0.42 0.65 42% boulders, 52% cobble, 2% gravel, 4% silt <br />Ul 4.3~ 4.54 58% boulders, 40% cobble, 2% gravel <br />Average: 0.43 0.65 <br />D1 0.67 0.77 62% boulders, 37% cobble, 1% gravel <br />D2 0.32 0.52 60% boulders, 33% cobble, 7% silt <br />D3 0.49 0.93 67% boulders, 30% cobble, 3% gravel <br />D4 0.51 1.02 93% boulders, 7% cobble <br />DS 4.35: 4.,52 72% boulders, 26% cobble, 2% gravel <br />Average: 0.47 0.75 <br />mainly of narrowleaf cottonwood and box elder trees, with varying amounts of shrub <br />understory, including gambel oak, chokecherry, serviceberry, snowberry, and red osier <br />dogwood. Trees were smaller and there were more shrubs in immature woodland than in <br />mature woodland. Unvegetated ground consisted mostly of boulder riprap placed by the <br />Colorado Department of Transportation during highway reconstruction, as well as areas <br />adjacent to the river channel covered by cobbles. Access to the river is generally restricted on <br />the south side. We found no large areas of recent disturbance, and other than areas of riprap, <br />or cobble areas neaz the river channel, most of the riparian land is well vegetated adjacent to <br />the river. Table 5 shows the percentage of each cover class bordering the channel. There was a <br />small percentage of the stream bank where the ground was eroded to form vertical banks (also <br />included in Table 5), however, most of the stream banks appeared to be stable. There were no <br />areas of overhanging banks or overhanging vegetation. <br />Water Quality: <br />The discharge plume was detectable by taking measurements of conductivity while wading <br />back and forth across the channel. The plume was only a meter or so wide at D1 and gradually <br />widened to encompass the northern third of the channel by the time it reached D3. Field <br />measurements of electrical conductivity taken at the sampling stations in Mazch and October <br />reflected the presence of the plume, and were highest immediately downstream of the <br />. 15 <br />