Sea Level Rise Adaptation Report for the City of Wilmington, North Carolina
In 2013, the City of Wilmington, North Carolina, in collaboration with New Hanover County and the Cape Fear Public Utility Authority (CFPUA), published the Community Resilience Pilot Project adaptation report. The report assesses the likely impacts of sea level rise on the area and presents adaptation strategies. Information from this report was intended to be incorporated into the County’s coastal zone management plan update and to educate City, County, and CFPUA officials for future decision making.
The City of Wilmington is located on southeastern coast of New Hanover County in North Carolina. Wilmington has a major port located along the Cape Fear River to the west, and is separated from the Atlantic Ocean only by a small chain of barrier islands, including Wrightsville Beach and Mansonboro Island Estuarine Reserve. Sea level rise and coastal flooding are major climate impacts of concern for the City.
The State of North Carolina requires that all coastal counties manage and update their coastal zone management (CZM) plans every 5-6 years, however, the same requirement does not exist for coastal municipalities. In 2016, New Hanover County adopted a comprehensive plan that was also used as an update to its Coastal Area Management Act (CAMA) Permit Program. Since the City of Wilmington does not have the same requirements for its CZM plan, the City’s comprehensive plan is not certified by CAMA. The City officially updated its CZM plan in 2010-11 and city planners are currently working towards incorporating the impacts of sea level rise into management. To date, there is not a mandate for city planners to consider the effects of climate change in North Carolina and there are no climate change-related projects being initiated by the City.
Despite the lack of a mandate, the City of Wilmington was one of the first jurisdictions to create a sea level rise adaptation plan in North Carolina. Part of the value and purpose of the report is to educate the leadership and begin a dialogue on regional climate change impacts with officials and communities. The final 2013 Community Resilience Pilot Project adaptation report focuses on water and wastewater infrastructure within the broader planning context related to sea level rise. A vulnerability assessment was also conducted as part of the study and focused on direct physical effects of sea level rise (e.g., damage to water supply wells and treatment facilities). Identified impacts on water and watershed infrastructure in the report included:
- Structural damage to infrastructure due to inundation and wave action
- Failure of treatment plant components and pump stations due to flooding of electrical controls and/or ancillary equipment
- Decay of infrastructure not designed for saltwater exposure
- Increase of inflow of seawater to sewer pipelines resulting in:
- Disturbance of wastewater treatment plant processes
- Changes in system hydraulics
- Increased operation and maintenance requirements
- Water quality standard compliance issues
- More frequent combined sewer overflows or sanitary water overflows
- Saltwater migration further inland into aquifers and freshwater estuaries used for water supply
In 2009, Wilmington began drafting the Community Resilience Pilot Project adaptation report to address the local impacts climate change may have within their jurisdiction. First, staff researched sea level rise reports, case studies, and adaptation plans from across the United States. Detailed, local scenarios of sea level rise were made possible by GIS data provided by Cape Fear Public Utility Authority (CFPUA), which allowed City planners to develop inundation maps under a variety of future conditions – aiding in a better understanding of potential risks. Stakeholder involvement was essential to the process of strategy development and solution identification. As part of the pilot study, a community resilience workshop was conducted where participants developed an ideal mission statement for the resilience project. The statement was intended for use by the City, County, and the CPFUA in future decision making.
Implementation of this adaptation report began in 2013, and the report has been most influential in its use as a model for recommendations for the City of Wilmington’s 2016 Comprehensive Plan. The report was used in terms of tools and strategies and a platform to build off of for the comprehensive plan’s coastal resilience and environmental sections. These parts of the comprehensive plan were then used to inform various initiatives including a land development code re-write by the City. The planning and environmental departments and the City are continuing work influenced by this plan and hope to have resultant products in the next few years. Other resources which were helpful to planning included low impact development (LID) best management practices and green building council information.
Currently, there is a desire to start another collaborative group between the City, County, and CPFUA to address community resilience and sea level rise and flooding impacts. There is continual communication between these groups, but a formal group has not yet been established. The City of Wilmington does work with local non-profits and their local community members as an active resource, speaking to groups, attending board meetings, and answering related phone calls. When planning projects are underway, the City makes community meetings a priority.
Outcomes and Conclusions
The Community Resilience Pilot Project adaptation report includes a series of matrices looking at impacts and adaptation strategies related to protecting natural resources, aquifer saltwater intrusion, damage to infrastructure, loss of public access to the shoreline, and loss of life and property. For each issue, short-term and long-term adaptation strategies were created that consider the ecological impacts, feasibility, government application, and cost to help city planners prioritize strategies. Strategies were organized in the report through a prioritization framework; those with the highest priority being those which aligned with the values, goals, and objectives of the organization which plans to implement them (i.e., local government departments, state-level agencies, communities). A total of 54 adaptation strategies were recommended, with adaptation strategies separated into two general categories:
- Infrastructure: strategies focused on the reduction of risks related to sea level rise for existing and future water and wastewater assets
- Land Use and Planning: planning efforts or studies to help guide and inform the decisions related to future land use, capital project implementation, and the adaptation to sea level rise; regulatory/incentive tools that can be used to guide development in the future to minimize risks related to sea level rise
The 2013 adaptation report included a series of next steps for the City’s, County’s, and CFPUA’s adaptive planning processes. The potential next steps mentioned in the report include:
- Establishment of a sea level rise working group
- Development of a monitoring plan for sea level rise
- Appraisal of the adaptation strategies suggested
- Defining decision trigger points or thresholds
Major take-aways were identified during the pilot project and report development, including:
- There must be a clear understanding of the goals and objectives of the planning effort, as well as a plan for dealing explicitly with uncertainty.
- A collaborative, stakeholder involvement process is essential.
- Well-managed and maintained GIS data provides a solid foundation for spatial planning efforts related to sea level rise.
- Assets management program data can be beneficially leveraged to support vulnerability assessments.
- Existing sea level rise scenario modeling allows for a quick definition of the extent of sea level rise implications.
- A prioritization framework is a valuable tool to identify priority adaptation strategies that are clearly linked to an organization’s values, goals, and objectives
- A facilitative leader with technical understanding of adaptive planning and training in decision support techniques is valuable to guide the planning process.
While a new report has not yet been released, the City is making progress on updating data and providing current planning recommendations. The City is updating zoning districts, flood plan regulations, and working on new flood maps which include sea level rise. The update to the 2013 report is intended to include setback and buffer requirements as well as adjustments in strategies and recommendation implementation. A new comprehensive plan has been approved and will include materials on coastal resilience and sea level rise, although the term “sea level rise” is not always used due to local politics.
Barriers to this type of work for the City include implementing actions at the community level; this is usually a process that takes much time and planning in order to execute in a way that the community will accept and adhere to. Environmental and development concerns in the area are also frequently barriers for the City. Plans that stem from the adaptation strategies may work for the City, however, there can be conflicts with local developers or other county and state agencies. This requires effective communication and priority-making between these various agencies at different levels.
Natural disaster events, such as Hurricane Florence (2018) serve as examples for the “new normal” for hurricane strength and impacts in the region. This has been a facilitator of action for the City in planning and securing funds for projects to address the environmental and development concerns that come with extreme weather.
Feifel, K. (2021). Sea Level Rise Adaptation Report for the City of Wilmington, North Carolina [Case study on a project of the City of Wilmington]. Version 2.0. Product of EcoAdapt's State of Adaptation Program. Retrieved from CAKE: https://www.cakex.org/case-studies/sea-level-rise-adaptation-report-city-wilmington-north-carolina (Last updated April 2021)