Laserfiche WebLink
<br />\ <br /> <br />e <br /> <br />e <br /> <br />e <br /> <br />new data developed for the Frenchman Creek study is in conformance with the CWCB's rules and <br />regulations for floodplain designation and approval. <br />Staff recommendation: Staff recommends that the Board: 1) designate and approve the 100-year detailed <br />floodplain information contained in said report within the City of Holyoke and unincorporated Phillips <br />County, and 2) authorize staff to prepare a floodplain resolution to be signed by the Director and <br />transmitted to the City of Holyoke and Philips County and to FEMA. This action is recommended in order <br />to meet statutory requirements. <br /> <br />2) Consent A2enda Item 2b <br />Floodplain Resolution Number: FPR 02-552 (tabled from the September 2001 meeting) <br />Affected Community: Town of Granby <br />Name of study to be formally acted on: "Floodplain Information Report, Town of Granby, Colorado" <br />dated March 2002. <br />Studied Streams: The Floodplain Delineation Study contains approximate studies for various streams <br />within Granby that are tributary to the Fraser River. <br />Technical Issues: The subject report for Granby was prepared by Montgomery Watson Harza (MWH) <br />under contract the Colorado Water Conservation Board to provide engineering and floodplain <br />administration information to support new approximate 100-year floodplain boundaries. The original <br />floodplain information for Granby consists of a very outdated Flood Hazard Boundary Map containing <br />approximate 100-year floodplain delineations for flood hazard areas in the community. That Flood <br />Hazard Boundary Map was prepared by the Flood Insurance Administration in 1975, and has been <br />used for over 25 years as the regulatory floodplain mapping for the community. Recently, the CWCB <br />with assistance from MWH completed new engineering analyses and a final report that provides useful <br />floodplain information for the community. The report also includes a description of how this <br />information can be used by the community to implement their floodplain regulations. <br /> <br />Hydrologic estimates for the 100-year peak flows on the studied streams were computed using <br />methods presented in Technical Release No. 55 - "Urban Hydrology for Small Watersheds" published <br />by the Soil Conservation Service (now NRCS). Channel cross-sections were estimated and/or field <br />surveyed at select locations on the studied streams in order to better estimate 100-year floodplain <br />limits. Normal depth calculations were used to estimate 100-year water surface elevations at the select <br />locations on the tudied streams. <br />Community response: The CWCB staff originally contacted Town of Granby staff by transmitting a <br />letter as notification of the proposed designation action for the subject Floodplain Information Report. The <br />Town was receptive to the proposed action and requested that CWCB staff travel to Granby to meet with <br />local officials in order to discuss the floodplain designation program and to discuss specific floodplain <br />issues in the community. The Town is very much in support of the new floodplain information, and has <br />transmitted a letter to the CWCB requesting formal Board action on the subject floodplain information <br />report. <br />Staff findings: The subject Floodplain Information Report for the Town of Granby contains the most <br />current floodplain information (approximate 100-year floodplain delineations) for the community, and it <br />supersedes an outdated Flood Hazard Boundary Map dating back to 1975. CWCB staff has determined <br />that the subject floodplain information for Granby is in conformance with the CWCB's rules and <br />regulations for designation and approval of approximate floodplain information. <br /> <br />Flood Protection. Water Project Planning and Financing. Stream and Lake Protection <br />Water Supply Protection. Conservation Planning <br /> <br />3 <br />