Board of Adjustment Agenda and Packet 2011 08 17

Home Browse Search

1303 Empire Road Floodplain 8 the existing building on the 1303 Empire Road site) were to be projected across the entire cross- section (as if the topographic ridge didn't exist), the resulting flood depth at the building site would be approximately 1 foot deep over the apparently pre-existing ground surface grade of 5307. At a minimum, it is apparent that any development, including placement of fill, construction of new structures, etc. on the 1303 Empire Road property would not result in obstruction or create any rise in flood waters, and would not adversely affect the flood carrying capacity of the flood hazard area. In addition, it appears that if any new building to be constructed on the site was to be designed so that the lowest floor, including basement, was elevated three feet above the existing grade (two feet above a flow depth of one foot or less), or elevated and/or floodproofed to or above a base flood elevation of 5308.1, with adequate drainage paths provided to guide stormwater around and away from the structure, the requirements for the issuance of a City of Louisville floodplain development permit can be met. Summary and Recommendations The following is a summary of the floodplain development conditions for the 1301 Empire Road property: • The site is currently considered by the City of Louisville to be in the Flood Regulatory District and will be required to obtain a floodplain development permit prior to any new land use, construction, or redevelopment of the site. The cumulative effect of any proposed enlargement of the existing building or redevelopment of the site, when combined with all other existing and anticipated development, will not increase the water surface elevation of the base flood. Certification by a registered professional engineer stating that any encroachment shall not result in such increase in flood levels during the occurrence of a 100-year flood can be provided. • Due to a reduction in 100-year flood flows as a result of the upstream Drainageway A flood mitigation project, flood flows have been substantially reduced and the actual special flood hazard zone is considerably smaller than that as currently shown on FEMA and City of Louisville floodplain mapping. The 1303 Empire Road property is in all likelihood outside of the area actually subject to inundation by 100-year flood flows. • The site can be developed to be fully in compliance with City of Louisville floodplain zoning criteria without extraordinary measures with regard to flood mitigation measures. • A Base Flood Elevation of 5308.1 (NGVD 1929) has been determined for the existing building location. 7115 Dry Creek Court Niwot, Colorado 80503 Phone: 720-231-3251 CURTPARKER55@hotmail.com