Chapter IV Improvements to Technical Mitigation
This section covers improvements to technical mitigation projects. Technical mitigation is defined here as the suite of coastal flood mitigation options including structural elements such as walls, levees, and gates, etc., and nature-based elements such as beach nourishment, shoreline stabilization, etc. This definition is based on U.S. Army Corps of Engineers (USACE) activities outlined in their Planning Guidance Notebook.87
Despite improvements to the NFIP and changes in zoning laws and building codes, there are many coastal areas across the US that will remain vulnerable to flooding or will become vulnerable in the future. A recent study estimates that cities like Miami, New York, New Orleans, and others across the US will see significant increases in flood risk by the year 2050, even assuming proper adaptation measures are taken to keep flood probability constant.88 This study finds increasing risk is primarily driven by increasing exposure due to coastal development. Other studies have found that increases in coastal flood risk will occur due to sea level rise89 and changes in extreme weather and storm climatology.90 Addressing changes in future hazard and exposure will require strategic investment in coastal flood defenses that protects valuable commercial infrastructure and communities located near the coast. The majority of large-scale technical mitigation projects are implemented in coordination with USACE and a non-federal partner, such as a state or local agency. Initially, the local/state entity submits a request for assistance. USACE then conducts a reconnaissance study to determine the scope and severity of the flood project. This is followed by a full feasibility study that evaluates potential plans and ends with a project recommendation. The evaluation and selection of the recommended project plan is based on maximizing “net economic benefits�.91 If a suitable plan is found, the project is sent for congressional approval, and ultimately Congress can appropriate funds for the project’s implementation. However, even if a project is authorized by Congress, it may not necessarily receive funds for construction. There is a backlog of hundreds of approved projects that have not received funds yet, and these projects total $60 billion in federal funding requests.92
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Problem Definition
