Seabrook, NH Plans for Sea-Level Rise

New Hampshire’s coast is only 13 miles long, but it is home to seven coastal municipalities. To help its coastal municipalities evaluate environmental risks, the regional Rockingham Planning Commission (RPC) pooled resources from:

The New Hampshire Homeland Security and Emergency Management (using a Pre-Disaster Mitigation Grant from the Federal Emergency Management Agency)
New Hampshire’s Geographically Referenced Analysis and Information Transfer (GRANIT) System
EPA’s Climate Ready Estuaries Program

As a result of this effort, in 2009 the RPC published the Adaptation Strategies to Protect Areas of Increased Risk from Coastal Flooding Due to Climate Change (PDF) (20 pp, 877 K, About PDF) and in 2015 it published the Tides to Storms Project (PDF) (52 pp, 2 MB, About PDF).

The project used coastal mapping data from the National Oceanic and Atmospheric Administration (NOAA) National Hurricane Center and LiDAR data collected by the United States Army Corps of Engineers as inputs to the COAST (Coastal Adaptation to Sea level rise) Tool. The COAST tool was then used to create visual, numeric, and presentation-based products that support the adaptation planning processes.

After accounting for regional subsidence, the COAST tool helped to project that by 2100 sea-level rise in New Hampshire could be approximately 2 to 5 feet.

The project also identified the vulnerability of each community’s assets and infrastructure from expected increases in storm surge and rates of sea-level rise. For example, if the ocean rises three feet by 2050, municipal and private assets in Seabrook, NH (worth between $107 million and $115 million) will be at risk during 100-year flood events.

The greatest identified risks were to:

Sewage pump stations
The NextEra nuclear power station
An Elementary-Middle School property
A wastewater treatment plant
State and local roadways

To address these risks in the short-term, the RPC recommended that Seabrook:

Update its regulations and zoning to elevate new development.
Separate development and infrastructure from tidal wetlands, freshwater wetlands and surface waters.
Create a coastal flood hazard overlay district.

In addition, the RPC has made recommendations to improve long-term planning and strengthen community outreach and engagement.

How did they do it?	Applicable EPA Tools
A regional commission collected and analyzed climate data for multiple communities Identified and used previous mapping efforts to accurately map current coastline covering seven communities. Created an Extended Coastal Flood Hazard Overlay that can be used to identify land that is subject to increased risk from sea-level rise and inundation.	Developed at the University of Southern Maine with funds from EPA, COAST is a technical tool, which can connect technical results with the social, political, and economic realities of local adaptation. With this software, users are able to conduct basic cost-benefit analysis. COAST (COastal Adaptation to Sea level rise Tool)* *Not an EPA-Tool
Working meetings were used to help local government stakeholders increase their understanding of regional data Stakeholders learned about risks and vulnerabilities, potential adaptations, and policy choices. Stakeholders developed increased decision-making capacities and effective communication skills for collaborating towards future sea-level rise adaptation planning.
Seabrook used a regional vulnerability assessment to evaluate risks to its assets and infrastructure Greatest risks include sewage pumping station inundation and vulnerable lands for schools, a nuclear power station, and a wastewater treatment plant.	The Steps to Resilience can help communities determine their vulnerabilities to the changing climate. Steps to Resilience (U.S. Resilience Toolkit)
Leveraging regional planning, Seabrook used its resources for adapting rather than community-specific studies The Rockingham Planning Commission (RPC) identified specific, action-oriented, short- and long-term steps to prepare for environmental changes and improve resilience to sea-level rise. RPC is assisting with a new Coastal Hazards and Climate Adaptation Chapter for the Seabrook Master Plan.	EPA’s Being Prepared For Climate Change Workbook outlines how communities of any size can take appropriate steps to develop a vulnerability assessment and risk-based plan Being Prepared for Climate Change Workbook EPA's Coastal Inundation Coastal Storm Surge Scenario illustrates hurricane strike frequency and worst-case coastal storm surge or inundation scenarios. EPA Coastal Inundation Coastal Storm Surge Scenario

How did they do it?

Applicable EPA Tools

A regional commission collected and analyzed climate data for multiple communities

Identified and used previous mapping efforts to accurately map current coastline covering seven communities.
Created an Extended Coastal Flood Hazard Overlay that can be used to identify land that is subject to increased risk from sea-level rise and inundation.

Developed at the University of Southern Maine with funds from EPA, COAST is a technical tool, which can connect technical results with the social, political, and economic realities of local adaptation. With this software, users are able to conduct basic cost-benefit analysis.

COAST (COastal Adaptation to Sea level rise Tool)*

*Not an EPA-Tool

Working meetings were used to help local government stakeholders increase their understanding of regional data

Stakeholders learned about risks and vulnerabilities, potential adaptations, and policy choices.
Stakeholders developed increased decision-making capacities and effective communication skills for collaborating towards future sea-level rise adaptation planning.

Seabrook used a regional vulnerability assessment to evaluate risks to its assets and infrastructure

Greatest risks include sewage pumping station inundation and vulnerable lands for schools, a nuclear power station, and a wastewater treatment plant.

The Steps to Resilience can help communities determine their vulnerabilities to the changing climate.

Steps to Resilience (U.S. Resilience Toolkit)

Leveraging regional planning, Seabrook used its resources for adapting rather than community-specific studies

The Rockingham Planning Commission (RPC) identified specific, action-oriented, short- and long-term steps to prepare for environmental changes and improve resilience to sea-level rise.
RPC is assisting with a new Coastal Hazards and Climate Adaptation Chapter for the Seabrook Master Plan.

EPA’s Being Prepared For Climate Change Workbook outlines how communities of any size can take appropriate steps to develop a vulnerability assessment and risk-based plan

Being Prepared for Climate Change Workbook

EPA's Coastal Inundation Coastal Storm Surge Scenario illustrates hurricane strike frequency and worst-case coastal storm surge or inundation scenarios.

EPA Coastal Inundation Coastal Storm Surge Scenario

Seabrook, NH Plans for Sea-Level Rise

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References

Climate Change Adaptation Resource Center (ARC-X)