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down in Mary E campground, after these trees were identified as a hazard to <br />public safety. '•W <br />Overbank flows no longer occur where the stream channel and floodplain are <br />affected by stream channel incision and the lowered water table. Overbank <br />flows are essential for establishing cottonwood seedlings (Rood and <br />Mahoney, 1990) as well as for groundwater recharge in riparian areas. <br />Further decline of the existing cottonwoods and the lack of seedling <br />recruitment are expected. It is likely that the cottonwood stand in Mary E <br />campground will not sustain itself over time, which will further reduce the <br />amount and quality of this valuable riparian habitat type in the South Fork <br />drainage. <br />In addition to the cottonwoods, other riparian vegetation has been impacted <br />by headcutting, channel incision and the lowered water table. Streamside <br />vegetation has been washed downstream as streambanks have eroded, and the <br />remaining vegetation is far above the water level (photographs 10-13), The <br />aquatic ecosystem is negatively impacted by the loss of streamside <br />vegetation and overhanging cover. These negative impacts include: lack of <br />overhead cover for fish, loss of habitat for terrestrial insects, and <br />reduced thermal regulation of stream temperatures in summer and winter. <br />Stream channel incision, bank erosion, and the loss of riparian vegetation <br />in the South Fork and mainstem San Miguel Rivers has resulted in a stream <br />channel which is wide and shallow, lacking pool habitat and instream <br />cover, and subject to higher stream temperatures in the summer, and lower <br />stream temperatures in the winter. <br />Channel incision, water table decline, streambank erosion, and <br />destabilization of the aquatic ecosystem has also resulted in the loss of <br />instream habitat improvement structures and negated cooperative efforts <br />between the Forest Service, Colorado Division of Wildlife, Trout Unlimited, <br />and other volunteers to improve fisheries habitat within this portion of <br />the South Fork of the San Miguel river. Boulder deflectors and weirs were <br />placed in the stream channel to increase the amount of pool habitat and <br />instream cover for fish. This habitat improvement project was valued at~ <br />$40,000 in 1985. Structures originally placed in 1984 and 1985 within reach <br />2 have been stranded out of the water as the stream downcut and water table <br />declined. Entire structures and portions of these structures have been <br />washed away in high flows as the channel bottom and streambanks continue to <br />erode. This has resulted in a reduction in the amount of pool habitat and <br />instream cover available in the South Fork of the San Miguel river. <br />Comments specific to the public notice and Telluride Gravel's proposed <br />activities <br />Alteration of the stream channel, streambanks, aquatic habitat, and <br />riparian vegetation in the area adjacent to'the gravel operation occurred <br />in a relatively short time period (between 1986 and 1993). This seems to <br />indicate that these impacts are associated with human activities, such as <br /> <br />