As sea levels rise and coastal storm events occur with increased intensity and frequency, many coastal communities — both human and natural — have become more vulnerable to coastal flooding hazards. Increasing resilience can improve a community’s ability to respond to and recover from these coastal hazards more quickly and with fewer resources. Often, the ecosystem services provided by natural landscapes can be leveraged to benefit nearby communities and reduce their exposure to impacts from coastal hazards, thereby improving resilience. Identifying hazards and exposed assets are necessary beginning steps.

The National Fish and Wildlife Foundation partnered with UNC Asheville’s NEMAC to develop a coastal resilience assessment that integrates geospatial analyses and modeling with the methodology of a resilience framework for the watersheds along our nation’s coasts. The assessment supports planners and project managers in:

1. Identifying where community and natural assets are potentially exposed to coastal flood hazards,

2. Locating priority natural landscapes that can be managed to improve community resilience, and

3. Improving habitat for essential fish and wildlife populations.

The data and models resulting from this assessment aim to identify which areas and what assets may be most exposed to coastal flood hazards, leading to further local analyses that can help guide a community’s prioritization of management options.

This presentation will provide an overview of the three-year development process for the assessment, including: (1) identification of key datasets and processes used for the analyses and modeling; (2) development and facilitation of stakeholder workshops in seven targeted watersheds along the East Coast (including in Charleston and the Cape Fear area); (3) identification of priority areas — or hubs — to guide the placement of large restoration or resilience-focused projects; and (4) the development of an interactive, web-based mapping tool to assist in the delivery and application of final results and data.

The South Carolina Department of Health and Environment Control (SCDHEC) - Ocean and Coastal Resource Management (OCRM) Office is presenting coast-wide results from the Hazard Vulnerability Assessment (HVA) tool.

The HVA tool evaluates coastal hazard vulnerability from four components: 1) Storm surge, 2) Shoreline change rate (erosion or accretion), 3) Flooding, and 4) Social/economic vulnerability (SoVI®). The final product is a vulnerability index on a scale of 1 to 5, with 1 being the least risk, and 5 being the most risk. In addition to this composite product, HVA also provides products for Inundation (surge + flooding), Inundation + SoVI®, and Shoreline Change (rate, plus temporal and spatial variations). Users can examine each hazard component to see which has the most impact in any given area

The HVA tool is an open source geospatial tool that can be used by coastal managers, planners, and researchers to improve hazard mitigation planning, emergency management, post-disaster redevelopment, and to determine areas best suited for restoration and mitigation. As an example, the HVA tool could potentially be utilized to support the Community Rating System (CRS) program by earning CRS credit under map information services, outreach projects, hazard disclosures, floodplain mapping, higher regulatory standards, additional map data, and floodplain management planning. The CRS, a voluntary National Flood Insurance Program (NFIP) incentive program, recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. As a result, flood insurance premium rates are discounted to reflect the reduced flood risk resulting from the community actions meeting the three goals of the CRS: 1) Reduce flood damage to insurable property; 2) Strengthen and support the insurance aspects of the NFIP, and 3) Encourage a comprehensive approach to floodplain management.

The SCDHEC OCRM ran the HVA tool statewide in the coastal critical area and has released the results through a new public web application.

The Lowcountry Council of Governments administered two Joint Land Use Studies (JLUS) focusing on maintaining and strengthening the military missions of Marine Corps Air Station Beaufort and Marine Corps Recruit Depot Parris Island while minimizing land use conflicts with the surrounding communities. One of the JLUS recommendations was to investigate potential effects of SLR. These bases, which have been highlighted for their potential for land loss from SLR, are major factors in the local economy of Beaufort County.

To address the JLUS recommendations, this study examined the risks to targeted infrastructure in the adjoining areas (e.g., roads, sewer, water) from SLR and the costs associated with maintaining essential service to the bases. The approach for identifying at-risk infrastructure was ‘scenario agnostic’. Rather than a set scenario, the envelope of SLR curves, adopted from the USACE and NOAA, were used to map the infrastructure’s relative risk from SLR for several different time periods. In addition to the risk envelope, this study includes uncertainty in elevation (lidar) and tidal (VDatum) data. The mapping datum was chosen based on an assessment of the inundation frequency; the level chosen had a 50% chance of occurring at least once each month.

Impacts of climate variability on the various infrastructure are time-dependent; planning for future work toward solutions necessitates a level of priority. Prioritization can either help bring various groups together or divide them. To achieve the former, it was deemed important to have a flexible, non-single scenario approach to the natural risks (SLR in this case); and a shared understanding of the importance of the existing or planned infrastructure components. The process included assigning the assets a vulnerability score for each time period based on its exposure and sensitivity to inundation at the chosen frequency; and a criticality score for its function and importance in providing services in the community and on the DoD bases. Finally, a replacement/retrofit cost was defined for each asset and used to define budget-level planning scenarios. The results and techniques of this resiliency project will be shared along with the hurdles and their working solutions.