FLOOD03129 - Laserfiche WebLink

Home Browse Search

. . . Chaffee County should regulate the approximate floodplains on a case-by-<:ase basis. A detailed floodplain analysis must be performed by a professional engineer and submitted by the development proponent for projects involving the Arkansas River mainstem and for other situations that fall outside the applicability of the Guidelines, An approximate floodplain analysis can be submitted by a developer or development proponent, for the allowable cases, in accordance with the determinations of the Colorado Water Conservation Board regarding the applicability of the Guidelines, Chaffee County may also require, at its discretion, that a detailed floodplain analysis be submitted in lieu of the use of the Guidelines methodology for any situation that it deems necessary, Hvdraulic Analvsis Hydraulic information used for streams with detailed floodplain delineations in Chaffee County's PIS is discussed in Section 3,2 of the PIS. In the case of approximate floodplains, the hydrology values obtained from the use of the Guidelines or from a detailed hydrologic analysis should be used in conjunction with an appropriate hydraulic analysis, Hydraulic analyses for determining lao-year water surface elevations for approximate floodplains may be perforined using FEMA's Quick-2 computer program, the Corps of Engineers' HEC-2 computer program, or other acceptable hydraulic methods, FLOODPLAIN MANAGEMENT Local Ordinance Reauirements Communities which manage their floodplains in Colorado do so most often through the local regulatory process, This requires a community to adopt an ordinance or regulation which sets forth the performance standards by which development will occur in identified flood hazard areas. Nationwide and in Colorado, regulations are enforced within the area of the lao-year floodplain. The basic requirement of these regulations is that new development and significant improvement of existing development cannot occur in the lao-year floodplain without a floodplain development permit being obtained, Obtaining such a permit requires compliance with engineering standards. In communities like Chaffee County that have detailed floodplain information, the engineering standards require that residential buildings must be elevated above the lao-year elevation and that non-residential buildings must be either elevated or floodproofed. Other structures or projects (i.e, bridges, culverts or fill) must be constructed in a way that minimizes the potential increase in flood elevations they may cause, For those areas like Chaffee County that have approximate floodplain information as well, the engineering standards have been more general, Structures must be built with materials and techniques that "minimize flood damages", The use of engineering techniques presented in this report can help the County to better regulate its approximate floodplain areas, 4