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• 1979 - Forest Service (FS~rveyed the South Fork San Mig~ and concluded <br />that this river had good potential for fisheries habitat improvement. <br />Report states that "riparian area is in excellent condition for the type <br />(cottonwood, willow, alder), stream channel is fair (due to limited pools). <br />1983 - FS fisheries biologist surveyed stream channel cross-sections from <br />the confluence of the mainstem and South Fork San Miguel rivers to Illium , <br />and from Sheep Corrals campground to the South Fork campground, prior to <br />planning instream habitat improvement structures. <br />1984, 1985 - FS and Colorado Division of Wildlife (CDOW), along with Trout <br />Unlimited and volunteers from Telluride High School, cooperatively work on <br />instream habitat improvement in the South Fork, primarily with instream <br />boulder placement and willow plantings. Total value of project estimated <br />at $42000. <br />1991 - Forest fisheries biologist documented degradation of riparian area <br />and stream channel, including stream channel downcutting, bank erosion, <br />headcutting progressing upstream from the confluence, decline of the water <br />table associated with this activity, and stream habitat improvement <br />structures left "high and dry" as a result. Documents that gravel mining <br />operations appear to be the primary cause of this decline. <br />1992 - Closure order on Mary E campground to remove 575 cottonwood trees <br />that are dead or dying. District fisheries and wildlife biologists <br />document concerns regarding the decline of the cottonwood riparian <br />ecosystem due to water table drop. Site visits are made and biologists <br />provide additional documentation of the effects from the gravel operation <br />on stream channel and riparian area. ~ <br />j <br />1993 - District fisheries biologist reports on the effects of cottonwood <br />tree removal and summarizes existing conditions of stream channel and <br />riparian area. Stream channel cross sections are resurveyed from the <br />confluence to Illium. <br />Direct and indirect impacts of gravel mining operation <br />Gravel mining has removed 118,000 cubic yards of material from National <br />Forest lands, has directly impacted about 7.5 acres (where the operation <br />has trespassed) through ground disturbance and removal of gravel material. <br />In addition, there are approximately 20 acres of riparian area off-site <br />impacts. There are additional impacts downstream on other public and <br />private lands. <br />Removing material from the stream channel has caused the channel to downcut <br />about 6-10 feet below the original streambed elevation, causing a <br />measurable change in the channel gradient (from 0.58 in 1983 to 2.58 in <br />1993, Reach 1 near the confluence). The headcutting (erosion progressing <br />upstream) has progressed 0.25 miles from the confluence. <br />Stream banks have eroded and are destabalized, stream channel has widened <br />and become more shallow, with a change in channel shape, and there is a <br />decline in the amount and quality of aquatic habitat (fewer pools, <br />increased sediments covering channel substrate, loss of riparian vegetation <br />providing bank stabalization and stream shading). <br />