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<br />~h)lG~)8 <br /> <br />Revised Supplemental Draft Environmental Assessment-Chapter 3-Affected <br />Enviromnent and Environmental, Consequences <br /> <br /> <br />" <br /> <br />Figure 12-Landslide Location Map. <br /> <br />canyon wall (Figure 12). Railroad tracks, owned by the Union Pacific Railroad, are <br />between the Colorado River and the over-steepened slopes of the landslide. The railroad <br />grade cuts through the toe of the landslide. <br /> <br />Issue: Fish passage alternatives could affect the stability of an existing landslide <br />and railroad. <br /> <br />Existing Conditions: The landslide in question is called the Tunnel No.3 <br />Landslide and is inspected annually as part of Reclamation's Upper Colorado Regional <br />Landslide Surveillance Program. Since, 1988, annual inspections have revealed no <br />visible evidence of movement, however, the slide has been active in the past. In February <br />and March 1950, this slide became active and collapsed part of Tunnel No.3 through <br />which water for the Government Highline Canal flows. Damage was so extensive that <br />the tunnel had to be rerouted further into the hillside in sandstone bedrock. The slide <br />disrupted railroad traffic as well, and the track alignments had to be reestablished <br />(Murdock, 1950). <br /> <br />39 <br />