SWG-2015-00444 - Jefferson County Engineering Department - Chambers & Jefferson Counties

Full Public Notice     Project Plans     Alternatives Analysis     Adaptive Management

The proposed project consists of restoring approximately 104,150 linear feet of dune ridge and beach face by hydraulically pumping sediment from a 241-acre borrow site located in the Gulf of Mexico (GOM) approximately 1.5 miles offshore from the project location.  The proposed beach widths would range from 200-300 feet in width and the dune crest heights would be approximately +6- to +9-foot NAVD88.  The beach nourishment and dune creation portion of the project would involve the discharge of approximately 4.1 million cubic yards of sandy material into 1,004.16 acres of tidally influenced beach and open water.  The applicant is proposing to place an unknown volume of fine-grained material (silt and clay) that would have to be dredged to get to the sand source for grade restoration in 1,021 acres of marsh shoreward of the proposed beach nourishment.  Any excess fine-grained material not used for grade restoration would be placed in the secondary 564-acre placement area just offshore from the proposed borrow site shown in the project plans.  The sediment would be excavated and hydraulically pumped to the shoreline through temporary pipeline corridors between the source and the beach, and then along the beach.  This method reduces the time-stamp any single pipeline is in place to approximately 180 days or fewer.  The  borrow area is in existing water depths of 18 to 27 feet.  The design criterion for dune elevation and beach height and width is intended to reduce inundation events into the NWR marshes, reduce shoreline retreat rates, and return sandy sediment to the littoral system.