Flow Path No. 39 is located north of the Flow Path 38 and extends from IH-10 to Doniphan Drive. Both flow paths converge as the low paths progress to the west of IH-10. The project also consisted of post-project conditions for the use of gabion mattresses and gabion baskets for the stabilization of the flow path. The flow path conveys a discharge runoff in the range of 3,600 cfs. The flow path improvements extend for approximately 2,600 linear feet. The project improvements consisted of th
CEA prepared an existing model analysis for HEC-HMS for the hydrologic conditions and HEC-RAS for the hydraulic conditions. Since the majority of the SFHA is within the unincorporated areas as per the effective FIRM, we established base flood elevations (BFE) for the flow path. Our analysis extended to establish a tie-in to the effective BFE for the upstream portion of the flow path. There are no effective BFE’s for the downstream portion of the flow path. The establishment of BFE for the existing conditions was required to properly conduct tie-in elevations as required by the Floodplain Management criteria for FEMA. The project required the preparation and approval of a CLOMR and LOMR for the channel improvements as well as approval by the USACE for an NWP for the channel improvements. The project utilized eco-friendly gabion mattresses for the stabilization of the channel.