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finalized the decision to place the spillway at this location, but it is currently the more favorable location for LaFarge. The channel proposed downstream of the spillway has been sized for 4,800-cfs and is anticipated to be grass-lined with aloes-flow channel. In this area, the drop structure has been proposed to be lowered 1-foot from where ICON had shown it in order to gain the required capacity. 5. Mike Applegate (Applegate Group, Inc.) explained the details of the channel design. He mentioned they chose shallower, wider channel sections for Bull Seep, downstream of the confluence with First Creek. Along this section of Bull Seep, they proposed a l-foot tall berm to handle low flows during mining operations. The channel was proposed with 3:1 sideslopes to help minimize the overall channel top width. Mike added that they looked at the design on a more global basis. They proposed to install aweir/drop structure at the South Platte River breakout location to pass ?,000-cfs into the Bull Seep Slough during a 6000 cfs event on the South Platte River. They also proposed a second, shallower structure on the Bull Seep Slough to stabilize areas to be backf`illed. The design proposed a riprap and plastic lined channel for 800-feet upstream of where the proposed Bull Seep discharges into the Bull Seep Slough (Section C). Mike mentioned that the pit would still need to be moved over 50-feet to accommodate the new channel, but this was not indicated on the plans. 6. Scott Franklin (USACOE) asked why the plastic channel lining was necessary. Mike Applegate replied that the ground water was high in this area and the lining was necessary to keep the ground water out of the channel as well as keep Bull Seep flows from seeping into the Sull Seep Slough (due to the elevation differences}. 7. Chris Lidstone (Lidstone & Assoc.) added more information on the design. He mentioned that the combination of dealing with the high groundwater and UD&FCD criteria for a wetland channel (Manning's 'n' of 0.08) resulted in a wider channel top width. Therefore, more trees may be affected than originally estimated. However, they approached the project with the assumption that restoring the hydrologic balance of the area was more important than saving trees. The group generally agreed with the approach. 8. Chris Lidstone also mentioned that some of the characteristics of the upstream basin have changed since the original study was completed and that the 100-year flow in the Bull Seep may be closer to 50-cfs, rather than 150-cfs. Bryan Kohlenberg mentioned the idea of rerunning the hydrology models in the area using updated land use values. 9. A discussion followed concerning the proposed weir at the breakout area on the South Platte River. There was some concern with whether or not the Brantner Ditch Co. would still get their decreed flow if the water surface was reduced on the South Platte River upstream. Barry Marrs (Brantner Ditch) would need to be contacted to get the answer to this. 10. Rick Anderson asked about the impact to the trees south of the Bull Seep/Firs[ Creek confluence. John Hickman responded that they proposed to follow the existing alignment. They felt that this alignment would have the least impact on the trees. The trees between the channel and the reservoir would remain in place. Scott Franklin mentioned that the tree loss in that area appeared unacceptable and suggested looking closer at the 50-cfs channel. His opinion was that he would prefer C:\1l_IXUQWti\TP.~II'\I_I-I ~ nlrtling_doc t':""'-~-..,"~ ~` •~ ` " ~.