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just above Highway US 24, plots at about twice the extrapolation of the 100-year discharge relationship along the Fountain Creek main channel. That is an appropriate discharge with the knowledge that Waldo Canyon has a much steeper gradient than Fountain Creek, 90 feet per mile (US Army Corps of Engineers, 1974), as compared to the 700 plus feet per mile for Waldo Canyon. , , Diversion/Conveyance Channels The development of the Summit Pit will regairo that changes be made to the existing condition of tho stream channels. It is planned that the channel capacity of the existing c s ag typified in figure Exhibit G-2 Mill be asintay ough the working pit during tho poriad of operat#ow to con normal flood flows. Inspection of the existing channels indicates that the normal flood flows within Waldo Canyon and the East tributary are much less than the design flow as derived by the HEC1 method. This is explained by the fact that the mean annual flows and the more frequent storm flows, up to about the 10-year storm are controlled by snowmelt. The infrequent storms like the 100-year event result from the large thunderstorms which produce the large flows as described in the flood plain information report for Fountain Creek (US Army Corps of Engineers, 1974). CMLRD comments include the recommendation that upland diversions be built to convey flows around the pit operations. This alternative is not feasible in that any upland diversions would have to be cut into the sides of the very steep canyon walls which would cause more disturbance than the present plan to route the existing channels,t~irough the pit area in approximately their current locations. The-.preeerrt plan is to meintafa err appropriate channel cross section through the pit area during operation in accordance with the cross sections as shown in Exhibit G-2. During reclamation. tbo plea is to rip ani blast, as required, a trapezoidal shape chaaa4l in the bedrock a~ depicted is figure Exhibit G-3. The size of the channels, by reach, are listed in Table 2. The channels are relatively wide compared to the depth because of the practical need to have sufficient width in the bottom to work heavy construction equipment to construct the channels in solid rock. As shown in the channel diagram, there is 1 foot of additional depth provided as freeboard. This is standard in channel design. Thn velocities which will occur during th4 d°~ a~ser-ere much higher than clef be perrei.seible in an erodible bed chaaasl. Howevor, ~inae tYwca channels will be cut into solid bedrock, there will be little problem of high velocities in the chenne2. ~urtaae Nater Responses: Summit Pit Application page 5