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of the lower portion of the Prospect ditch were field checked using a Suunto PM-5 <br />Clinometer. <br />Station Field Readin_g Map 33 <br />5 to 6.5 10 degrees 7 degrees <br />6.5 to 8.5 14 degrees 7 degrees <br />8.5 and up 16 degrees 16 degrees <br />Potentially the lower portion of this ditch is steeper than the design plan. This could <br />result in erosion of the riprap channel unless careful field design practices are <br />implemented. Some gullies have already occurred, especially from flow from the <br />north, above the substation road. Conditions are "worst case" at the present time due <br />to the lack of topsoil and vegetation. <br />At this time, we do not have a survey of the profile of the Prospect Ditch, although the ditch is <br />apparently to final grade along its entire length. There is no practical reason to delay verification that <br />the drainageway has been reconstructed as per the approved plan with respect to the grade. <br />However, with the addition of riprap and the topsoiling of areas adjacent the ditch, it is unlikely that <br />any deviation with the approved plan would result in changes to the ditch. Nonetheless, it should be <br />recognized that a steeper grade than what was planned and approved (and subsequently used in <br />SEDCAD design for the Prospect pond) could be a contributing factor to any future problem that could <br />develop in the watershed. I re-iterate; <br />I recommend that we get as-built, profile survey information for Prospect drainageway <br />as soon as possible. <br />Continuing with text (in italics) from my May 2007 memo; <br />Secondly, field inspection and recent aerial photographs indicate large backfilled areas that <br />are at final grade in the Prospect watershed and now drain directly to the Prospect sediment <br />pond rather than the former East Pit. This now puts the Prospect pond under significant <br />pressure as the sole sediment control treatment facility for this drainage area. Annual <br />Reclamation Report maps do not currently show the number of acres at final grade, making it <br />diflrcult to determine the exact number of acres that currently drain to the pond but have yet <br />to be topsoiled and reseeded. The number of backfilled acres will only increase as Colowyo <br />completes backfilling of the East Pit and constructs the Final East Pit drainageway and the <br />North Tributary to the East pit draingeway. <br />• 1 recommend that we have Colowyo add 8 & G acres to the ARR map each year. <br />Colowyo add backfilled and graded acres to the Annual Reclamation Report map in <br />2007, all of which were in the West Pit area. This concern is resolved. <br />Continuing with text (in italics) from my May 2007 memo; <br />The hydrology, sedimentology and design of Prospect pond have been the subject of much <br />debate and revision since 1992. Colowyo has consistently defended both pre-approved <br />curve numbers for modeling as well as other hydrology design assumptions. They have also <br />vigorously defended their practice of designing ponds for a worst case condition that <br />assumes that various portions of the watershed are in different stages of reclamation after the <br />