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.. October 29,2001 Memorandum for File Subject: Meeting at Greeley, Colorado, October 25,2001 A meeting was held at 1300 on October 25, at the Greeley City Offices. Tom Gorman represented the Corps of Engineers and Tom Browning attended for the Colorado Water Conservation Board (CWCB). The meeting was organized by Steve Bagley ofthe Greeley Public Works Department, several others from the department also attended. John Liou ofFEMA Region VIII was invited, but had other commitments. The purpose of the meeting was to discuss the flood plain delineation study for the Cache La Poudre River through the city of Greeley being conducted by the Omaha District for the CWCB as part of the Federal Emergency Management Agency's Cooperating Technical Partners (CTP) program. The purpose ofthe CTP study is to convert the results of a 1998 Corps Flood Plain Management Services (FPMS) program study of the Cache La Poudre River in Greeley in Weld County into FEMA format and to make some changes requested by the City. The 1998 Corps study used cross sections from a 1997 hydraulic model for the river through Greeley developed for the City by their consultant as well as new cross sections obtained upstream and downstream from Greeley at locations designated by the Corps. The FPMS study was funded by the Corps with the surveys provided by the City with funding assistance from the CWCB and Weld County. In the FPMS study, adjustments were made mainly to the encroachment parameters in the consultant's 1997 hydraulic model. It was assumed that the cross section and bridge geometry in the consultant's hydraulic model was adequate. The floodway delineated by the consultant was not satisfactory, so the FPMS study revised the floodway delineation through Greeley as well as downstream and upstream of the city. For the CTP study, the City obtained some channel survey information at the 8th Street Bridge. The City was concerned about an abrupt three foot jump shown in the channel bed immediately upstream of the bridge. The City's surveys did not find such an abrupt change in the bed elevations. The City also surveyed top of bank elevations along the river between 8th Street and 5th Street. At several cross sections in this reach, the top of bank elevations used in the hydraulic model were several feet off from the surveyed elevations. A possible reason for this was that spoil bank levees along the banks in this reach were damaged and rebuilt after a flood in 1993 and the data in the hydraulic models was from 1987 aerial photos. The City was also concerned that several bridges in the study reach have been replaced since 1987 and it is not certain that the new bridges were included in the consultant's hydraulic model. The result of all this is that the City now has a low level of confidence in the cross section and bridge data provided to the Corps for the reach between Ash Avenue and 25th Avenue.