Delaware Sea Level Rise Adaptation Initiative
The Delaware Coastal Management Program in the Department of Natural Resources and Environmental Control (DNREC) created a statewide Sea Level Rise Initiative. Scientists and managers worked together to compile information on existing infrastructure, inundation maps, and vulnerabilities of tidal marshes and wetlands, and to incorporate resilience into planning and management. This case study provides information on the type of data being collected, Delaware’s process of data collection and strategy development, and subsequent sea level rise adaptation strategies.
DNREC is concerned with sea level rise and its resulting impacts, including habitat loss, flooding of low-lying areas, and saltwater intrusion. To prepare for these projected impacts, DNREC and its associated coastal programs implemented a Sea Level Rise Initiative to educate stakeholders, provide technical assistance, and develop sea level rise policies. This project began with a 2009 workshop for a variety of stakeholders to discuss the implications of sea level rise in Delaware. Attendees identified four steps to developing a statewide Sea Level Rise Adaptation Plan:
- Issues Characterization: Review existing sea level rise studies and identify additional data necessary for a statewide adaptation plan.
- Issue Prioritization: Identify and prioritize areas that will experience the most social, economic, and environmental impacts from sea level rise.
- Strategy Development: Explore potential adaptation strategies to inundation. The strategies developed will provide the framework for the adaptation plan.
- Implementation: Managers and policymakers begin to implement the adaptation plan.
An Issue Characterization Workshop was held in 2009 with scientists, state and local officials, non-profit organizations, academia, and business representatives. Together, participants identified 61 sea level rise issues related to the economy, natural resources, public health and welfare, and infrastructure.
Building upon the collaboration of stakeholders in 2009, a Sea Level Rise Advisory Committee (SLRAC) was established the following year to conduct the second step of the process: Issue Prioritization. To identify high-impact areas within the state, SLRAC conducted a vulnerability assessment. The committee identified resources of concern (e.g., historic sites, critical wildlife habitat), collected geographic datasets (e.g., roads, public safety facilities), assessed exposure by overlaying resources of concern with multiple sea level rise projections, identified potential impacts of inundation (e.g., loss of infrastructure, loss of jobs and revenue), and assessed risk by synthesizing collected data to determine each resource’s exposure, the scope of impact, and functionality if inundated. The SLRAC’s vulnerability assessment identified 16 statewide resources of high concern including tidal wetlands; dams, dikes, and levees; heavy industrial areas; evacuation routes; and habitats of conservation concern.
The third step of developing a statewide adaptation plan—Strategy Development—was completed in 2013. A SLRAC report breaks adaptation strategies into four categories:
- Avoid: limit development in areas particularly vulnerable to inundation and redirect development to areas that are less at risk. Tools to implement this strategy include conservation easements, transfer of development rights, and setback regulations.
- Accommodate: implement short-term solutions that allow for continued use of a resource. Examples of accommodation strategies include elevating structures, constructing floodgates, and building green infrastructure such as water retention ponds.
- Protect: preserve existing resources by blocking possible inundation. This is done with measures such as bulkheads, dikes, and beach nourishment projects that slow erosion.
- Retreat: allow for natural shoreline movement. This strategy can be achieved through managed retreat, “rolling easements” that move inland with the coastline, and land acquisition.
In addition to suggested adaptation strategies, the report produced a list of objectives for the state of Delaware, such as increased availability and quality of sea level rise data, consistent policies for future growth and investment, and improved avenues for communication between local, state, and federal entities regarding sea level rise.
To aid in the final step of creating an adaptation plan, an implementation workshop was held in 2014. The goal of this workshop was to build upon the strategies recommended in the SLRAC’s 2013 report by suggesting specific activities that can be undertaken. To develop suggested activities, workshop participants were divided into four groups: Infrastructure and Transportation; Water Resources; Socioeconomics and Land Use; and Shorelines, Wetlands, and Habitat. Within each of these categories, participants broke down broad recommendations into specific actions. For example, a broad recommendation within Shorelines, Wetlands, and Habitat was to create a comprehensive wetland protection, restoration, and retreat strategy. Specific activities developed by the thematic workgroup included updating wetland maps to include coastal migration zones, assessing transition zones to prioritize land acquisition efforts, and conducting educational programs for affected landowners.
Outcomes and Conclusions
The result of this initiative is a series of reports titled “Preparing for Tomorrow’s High Tide.” The series is available online and thoroughly documents each step in the development of this adaptation initiative. These reports now serve as a guide for both state and local adaptation initiatives by providing actionable strategies for communities highly vulnerable to sea level rise.
Gregg, R. M. (2021). Delaware Sea Level Rise Adaptation Initiative [Case study on a project of the Delaware Coastal Management Program]. Version 2.0. Product of EcoAdapt's State of Adaptation Program. Retrieved from CAKE: https://www.cakex.org/case-studies/delaware-sea-level-rise-adaptation-initiative (Last updated August 2019)