12-19-1996 Public Hearing and Regular Meeting of the La Porte Planning and Zoning Commission

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• • f{FV97-001 Page 6 of 8 1/16/97 Duplicate Effective Model 2. Upon receipt of step-backwater computer model, the engineer should run the original step-backwater model to duplicate the data in the effective FIS. Existing Conditions Model 3. Revise the original step-backwater model to reflect site specific existing conditions by adding new cross-sections in the vicinity of the proposed development (two or more cross-sections) without the proposed development in place. Floodway limits should be manually set at the new cross-section locations by measuring from effective FIRM or FBFM. The cumulative reach lengths of the stream should also remain unchanged. The results of these analyses will indicate the 100-year floodway elevation for revised existing conditions at the proposed project site. Proposed Conditions Model 4. Modify the revised existing conditions model to reflect the proposed development at the new cross-section, while retaining the currently adopted floodway widths. The overbank roughness coefficients should remain the same unless a reasonable explanation will impact Manning's "n" values should be included with the supporting data. The results of this floodway run will indicate the 100-year floodway elevations for proposed conditions at the project site. The results must indicate NO impact on the 100-year flood elevations, floodway elevations or floodway widths shown in the Duplicate Effective Model or in the Existing Conditions Model. The original FIS model, the duplicate effective FIS model, the revised existing conditions model, and the proposed conditions model should all produce the exact same results. The "no-rise" supporting data and copy of engineering certification must be submitted to and reviewed by the appropriate community official prior to issuing a permit.