The Mobile District has successfully applied EWN principles and leveraged relationships at the local, state, and federal levels to implement sound and sustainable projects along the northern Gulf Coast. The federally authorized Mississippi Coastal Improvements Program (MsCIP) is a great example where Mobile District constructed nearly $500M in projects, to date. Our goal is to continue to expand on our successes, share our lessons learned, learn from others with an open mind, and grow our collaborative spirit through the continued execution of projects in the Northern Gulf in Mississippi, Alabama, and Florida.
Island Creation – Discovering placement solutions with multiple benefits
Cat Island and Ship Island, Mississippi, United States
Creating valuable habitats while protecting the mainland coast and Mississippi Sound. Hurricane Camille cut Ship Island in half when it raged through the Gulf Coast in 1969. The 5.6-kilometer breach between East and West Ship Islands, known as Camille Cut, had almost naturally healed when Hurricane Katrina carved it open again in 2005. Meanwhile, Cat Island, another barrier island off the coast of Mississippi, had lost hundreds of acres of land to erosion. The two islands represented a critical opportunity to restore the Mississippi coastlines’ first line of defense against coastal storms. The U.S. Army Corps of Engineers (USACE)–Mobile District partnered with Mississippi’s Secretary of State’s Office and the Mississippi Department of Marine Resources to restore Cat Island and the National Park Service to restore Ship Island, the latter of which is the second-largest restoration project in the history of the National Park Service. Using millions of cubic meters of sand and reused dredged sediment, the project teams restored areas of both islands, creating valuable beach and dune habitats and enhancing their ability to absorb wave energy, sheltering the mainland Mississippi coastline.
For Ship Island, the riskiest part of the project was closing Camille Cut without significant sediment losses, and the most challenging for Cat Island was matching sand grain size and color to the native beach. In both cases, extensive scientific research and on-site investigations ensured the technical precision required to succeed. For Cat Island, researchers identified a borrow site through a partnership with the U.S. Geological Survey. The Ship Island project team took advantage of hydrodynamic and morphological modeling to choose the most effective method of closure. For both, scientific and engineering expertise translated to cost savings and successful outcomes.
Both islands have specific erosion patterns, so the project teams worked with these natural tendencies to minimize sediment losses during construction. Plantings of native plant species, such as Gulf bluestem (Schizachyrium maritimum), sea oats (Uniola paniculate), and bitter panic (Panicum amarum), further maximized sand retention and natural revegetation. On Ship Island, many plantings were from cuttings and seeds from the island itself, taking advantage of an already available natural resource. The two projects planted a combined 415,000 plants, which established healthy stands within months of installation.