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<br />I <br />I <br />Not all the sediment from the ski area and ~se area private <br />land would be deJ;:osited in the East and West ~orks of the San <br />Juan River as same in-channel storage, trappi~g and detention <br />would occur. However, a conservative assunq;>tion that all the <br />sediment would enter the East and West Forks was used to <br />estimate the maximum amount of sediment whictl would occur in <br />. East and West Forks (Table IV-8). I <br />I <br /> <br />The net maximum :impact of developnent o~ West Fork is <br />sUl1Ullarized in Table IV-9. These increase's in suspended <br />sediment load include the residual effectis of watershed <br />disturbance during previous years as noted abbve. <br />I <br />, <br />The increased suspended load fram the! ski area and <br />developnent on private land is a small incri2ase compared to <br />the amount of sediment currently being traj1sported through <br />the project area. The estimated 227.6 tbns of sediment <br />increase in the West Fork in 1990 is 0.29% of the annual <br />total 77,426 estimated tons at the county liIhe West Fork gage <br />site in 1985 and only 10.3% of the 2210!tons of sediment <br />transport which occurred at the West Fork gage in a single <br />day on June 10, 1985. No significant cha~ges in the West <br />Fork sediment discharge characteristics or s\'KIiment transport <br />capability would occur with the addition o~ this relatively <br />minor increment of sediment. An estimated! annual total of <br />16.1 tons of sediment would be introduced into the East Fork <br />of the San Juan River via West Treasure Creek during the back <br />bCMl developnent in Alternative Two (Table I"'-8). This would <br />be a virtually iImreasurable sediment inp6.ct on the East <br />Fork. This sediment increase would be expected to quickly <br />reduce with revegetation of disturbed aveas in the back <br />I <br />bCMIs. I <br />I <br /> <br />, <br />I <br />PRnm=::: :~D==F IN <br />I <br />I <br />IN:RFACJID SUSPENDF:fl SFm~ LaM (TONS) <br />1990 1995 2000 2007 2010 <br />I <br /> <br />TABLE IV-9 <br /> <br />WATERSHED <br /> <br /> I <br /> I <br />WIIDY PASS CREEK ~O.O +15.0 +15.0 +~5.0 +15.0 <br />BOOl'JAO< CREEK +36.8 +9.2 +9.2 -\-9.2 +9.2 <br />ELK CREEK 0 0 0 ~2~4 +35.6 <br />BUlTRESS CREEK 0 0 0 +1.3 <br />PRIVATE LAND 130.8 +32.7 +32.7 +~2.7 +32.7 <br /> , <br /> I <br />TOrAL +227.6 +56.9 +56.9 +59.3 +93.8 <br /> , <br /> <br />178 <br />