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. Community response: The District transmitted a letter dated December 20, 2001 requesting the CWCB to review and designate the subject floodplain information. District staff was notified by telephone call on January 15, 2002 of the proposed CWCB action at the January 2002 Board meeting. The District staff is very familiar with the CWCB designation and approval process and therefore did not request any clarification regarding the proposed action. Douglas County coordinated closely with the District during the development and review of the subject study, and the District's consulting engineer addressed their comments. Staff findings: CWCB staff has determined that the subject detailed floodplain information for the Plum Creek watershed is in conformance with the CWCB' s rules and regulations for floodplain designation and approval. The 100-year flood profiles and floodplain delineations are reasonable and appear to accurately describe flood hazards along the studied stream reaches. The most current regulatory floodplain mapping published for the Plum Creek mainstem was studied by detailed methods, and is currently shown as a numbered A Zone in the existing Flood Insurance Study (FIS) for Douglas County. CWCB staff finds that the old detailed delineations in the existing FIS should be replaced with the detailed information contained in the November 2001 Flood Hazard Area Delineation presented here for designation and approval. Staff recommendation: Staff recommends that the Board: 1) designate and approve the 100-year detailed floodplain information contained in said report within unincorporated Douglas County, and 2) authorize staff to prepare a floodplain resolution to be signed by the Director and transmitted to Douglas County, the Urban Drainage and Flood Control District and FEMA. This action is recommended in order to meet statutory requirements. . 3) Ae:enda Item 2.d Floodplain Resolution Number: FPR 01-559 Mfected Community: Town of Otis and Washington County Name of study to be formally acted on: "Technical Review and Revised Hydrology Report, Southwest basin in the Town of Otis, Colorado" dated October 2001 - prepared by the Colorado Water Conservation Board. Studied Streams: The report includes detailed lOO-year hydrology information for the Southwest drainage basin affecting the Town of Otis, Colorado. The studied watershed is in the Republican River basin. Technical Issues: The Town of Otis requested that the CWCB assist the community in addressing a number of questions regarding the town's floodplains. Questions were raised about the validity of the flood hydrology for the southwest drainage in Otis. The CWCB performed fieldwork and technical analyses to address concerns about the flood hydrology. Several site visits were made to survey cross- sections and to collect necessary data. A number of revisions were made to the hydrologic analyses to take into consideration comments and concerns from Town officials and affected property owners. In summary, the revised 100-year peak flows for the Southwest Drainage at the Town of Otis are approximately 50% of the original flows that were presented by the CWCB at the onset of the study. Community response: The Colorado Water Conservation Board staff prepared the subject study and therefore is requesting designation and approval on behalf of the Town of Otis. Town officials h:we been involved in the technical process and are well aware of the development of the study as well as the results and implications for floodplain management. A full report was transmitted to the Town and to several other interested parties, including a very outspoken and concerned citizen within the commnnity. A letter from that citizen was received by CWCB staff acknowledging the detailed hydrology work and accepting the results. Town officials have been in verbal communication with the . Flood Protection. Water Project Planning and Financing. Stream and Lake Protection Water Supply Protection. Conservation Planning 5