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<br /> <br />Results of storm event of 5-24-92 of less than 1.8 inches <br />(Pit not actually in place to intercept the bulk of runoff. <br />Topsoil had bean removed from a large area above the South <br />Collection Ditch.) <br />According to remarks made immediately after the storm event by Rent <br />Gorham and Juan Garcia, there was enough runoff involved is this <br />storm event that, had it all reached the Prospect Pond, the <br />secondary spillway would have discharged and the pon8 itself could <br />quite possibly have failed. <br />Discharge great enough to erode massive amounts of topsoil and <br />subsoil and to cause failure to the South Collection Ditch in <br />several places, resulted in rocks and sediment crossing highway and <br />leaving the permit area. <br />Raters reached velocities severe enough to erode parts of channel <br />to bedrock and undercut sideslopes. <br />From the results of this event, it is evident that the models <br />submitted by Colowyo incorrectly designated the worse case scenario <br />and that many of the assumptions made (curve numbers, etc) failed <br />to adequately predict the results of a designed event. it is <br />important to realise that the structures built were designed to <br />adequately pass and/or contain volumes or velocities of water and <br />sediment as incorrectly modeled. <br />Enclosures <br />cc: Rent Gorham, Dan Hernandea <br />