Revolution Mill FEMA Permitting
Client: City of Greensboro, NC
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Services provided in this project:
Revolution Mill, a historic textile mill complex in Greensboro, is being re-developed for commercial, office and residential uses. The structures on the site include two buildings constructed over North Buffalo Creek at a point where the upstream watershed is about 15 square miles. Much of the contributing drainage area has been developed since the construction of the buildings and the flow regime has changed accordingly, increasing the risk of flooding on the site. Much of the site is mapped within the FEMA regulatory floodplain and all re-development has to be done under a “no-rise” constraint such that flood risks on the site and in upstream areas are not increased.
JEWELL Engineering has been working with the property owners, Self-Help Venture Fund, as they seek to comprehensively assess and mitigate flood risks as the site is being re-developed.
Phase 1 of JEWELL’s effort was to refine the effective FEMA hydraulic model to better account for flow conveyance through the site under existing conditions. A request for a Letter of Map Revision was filed with FEMA and the North Carolina Floodplain Mapping Program (NCFMP) was filed in July 2013, approved in January 2014, and became effective in June 2014. With the revised base flood elevations (BFEs) about three feet lower than the previously effective levels, the owners were able to proceed with remodeling of buildings, with a provision of floodproofing up to the level of the lowest window panes.
Phase 2 involved assessing the impacts to flood risks associated with various potential improvements on the site, including improving flood conveyance around the buildings, removal and/or modifications of some of the crossings and structures, and the addition of a new pedestrian bridge. After the owners, architects and site engineers developed a site plan for submittal to the City of Greensboro, JEWELL was asked to prepare a hydraulic analysis and documentation for approval by the City under a No-Rise Certification and also a submittal to FEMA/NCFMP for a Conditional Letter of Map Revision, for further confirmation of the lower post-project BFEs which will negate the need for any sealing of windows on the buildings.
JEWELL has also provided assistance to the Revolution Mill owners on other aspects of site development, including planning for a greenway through the site along North Buffalo Creek, setting up a comprehensive investigation of all subsurface utilities on the site, and permitting with the Corps, DENR and the City of Greensboro for work impacting the stream and adjacent riparian buffers.