As the prime consultant, A&O conducted a preliminary flood study and WCE conducted the CLOMR preparation including FEMA submittal. A&O coordinated topographic survey, wetland delineation, riparian buffer delineation, and 401/404 permitting and an endangered species survey through WR, and the geotechnical subsurface investigation was performed by F&R. The A&O team also completed a feasibility study on Walnut Creek that included structure 88 and a non-FEMA flood study. Structure 88 was combined with Structure 37 to develop construction plans and specifications.

Since Structure 37 is built on top of the existing sewer main, the bridge was relocated immediately downstream to clear it of the utility. The new structure design consists of a 12 foot- wide prefabricated truss structure that will sit upon cast-in-place (CIP) concrete end bents on H-piles with a load carrying capacity of 5,000 lbs. (H5 load). The owner wanted to remove structure 88 and replace the existing three-span structure in the same location. The new structure will consist of glulam beams, timber decking, and rails supported by concrete caps on H-piles and concrete wing walls and will remain in the same general foot print as the existing boardwalk.

After meeting all the owner’s requirements and determining the structural elements for both structures, A&O developed construction drawings, project specifications, and an estimate of probable construction costs for review of the project. Currently, A&O also provided bid assistance and construction administration of both bridge replacements.