City of New Castle, Delaware Coastal Resiliency Action Plan

Rachel M. Gregg
Posted on: 3/29/2010 - Updated on: 10/28/2021

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Rachel Gregg

Project Summary

As part of their statewide Sea Level Rise Adaptation Initiative, the Delaware Coastal Programs Office of the Division of Soil and Water Conservation in the Delaware Department of Natural Resources and Environmental Control (DNREC) partnered with the City of New Castle to conduct a vulnerability assessment and develop a coastal adaptation plan to prepare for and adapt to sea-level rise and other projected climate change impacts. This project examined the physical, social, economic, and environmental vulnerabilities of the City of New Castle’s coast in order to identify issues of concern and develop adaptation strategies. Following several public workshops, a final vulnerability assessment and adaptation plan for New Castle was released in 2018.


The Delaware Coastal Programs Office of the DNREC created a Sea Level Rise Initiative to help assess vulnerabilities and plan for projected impacts of accelerated sea level rise to the Delaware coast. One aspect of this has been the design of implementation projects to assist coastal communities in the state; one such project was implemented in the City of New Castle. This project was designed to assist New Castle in its efforts to reduce existing vulnerabilities along the coast as well as to help plan for future rising sea levels and other climate change impacts. Current coastal issues in New Castle include flooding and erosion from storms, which have stressed dikes, tide gates, and stormwater management systems throughout the community. More intense storms and sea level rise have the potential to overwhelm the community, resulting in complete dike failures, inundation, habitat loss, and infrastructure damage.


The vulnerability assessment and adaptation plan were developed through a step-wise process:  document review of existing coastal infrastructure and adaptation strategies; vulnerability mapping; identification and prioritization of vulnerabilities; public engagement; and recommended actions and activities.

  1. Document review: The Delaware Coastal Programs Office contracted firms to collect data on statewide coastal adaptation strategies with a focus on New Castle’s existing dikes and bulkheads, including:
    • Dike breach analysis and inundation mapping for selected dikes;
    • Emergency action plans and response protocols for selected dikes;
    • Operation and maintenance manuals for dikes;
    • Bulkhead replacement analysis, including design suggestions for ecologically integrated infrastructure such as living shorelines; and
    • A Coastal Protection Concept Study identifying potential storm surge impacts.
  2. Vulnerability mapping: Detailed vulnerability mapping was conducted to identify the areas of New Castle most susceptible to flooding.
  3. Identification and prioritization of vulnerabilities: Infrastructure was assessed for its sensitivity and adaptive capacity to inundation in order to identify priority areas.
  4. Public engagement: Using the outcomes of the vulnerability assessment, adaptation strategies were developed with input from community stakeholders through a series of public workshops.
  5. Recommended actions and activities: Combining collected data and community input, a final report of recommended actions and activities was developed and published. Recommendations include the estimated timeframes (e.g., near-, mid-, and long-term) and costs of each activity. Recommended activities include:
    • Guide growth away from areas most susceptible to flooding;
    • Re-evaluate city emergency operations;
    • Provide resources to residents and businesses that allow them to learn about their own vulnerability to rising sea levels;
    • Provide economic incentives for residents and businesses to implement flood management techniques that would reduce city expenses of disaster mitigation;
    • Create groundwater models to map saltwater intrusion; and
    • Raise existing dikes to further reduce impacts from storm surges.

Outcomes and Conclusions

The plan identifies specific coastal vulnerabilities and outlines targeted strategies to address current and future sea level rise, coastal storms, and other climate change impacts.


Gregg, R. M. (2021). City of New Castle, Delaware Coastal Resiliency Action Plan [Case study on a project of the Delaware Coastal Management Program]. Version 2.0. Product of EcoAdapt’s State of Adaptation Program. (Last updated September 2021)

Project Contacts

Position: Planner IV

Affiliated Organizations

The management of Delaware’s coastal resources is shared by a number of entities within the Delaware Department of Natural Resources and Environmental Control.

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