Coastal Resilience

Introduction

Sea levels are rising. Coastal storms happen. Erosion happens. Ideally, coastal communities and infrastructure would be built far enough back from the coast to be protected from these threats. But the reality is that there are a lot of people and a tremendous amount of coastal infrastructure in harm’s way that can’t be easily moved.

So, what can we do?

Coastal resilience is part of the answer. Coastal resilience means building the ability of natural and human communities to "bounce back" after hazardous events such as hurricanes, coastal storms, and flooding – rather than simply reacting to impacts. A community that is more informed and prepared will have a greater opportunity to rebound quickly from weather and climate-related events, including adapting to sea level rise. The ability to rebound more quickly can reduce negative human health, environmental, and economic impacts.

Coastal Resiliency Principles and Framework

One of the leaders in understanding coastal resilience and applying coastal resilience principles to address threats to our coasts and the people that inhabit them is The Nature Conservancy (TNC). Their coastal resilience framework supports decisions to reduce the ecological and socio-economic risks of coastal hazards. The framework includes 4 critical elements:

Raise Awareness: Develop integrated databases on social, economic and ecological resources critical to communities and provide mapping and visualization tools;
Assess Risk: Assess risk and vulnerability to coastal hazards including alternative scenarios for current and future storms and sea level rise with community input;
Identify Choices: Identify choices for reducing vulnerability focusing on joint solutions across social, economic and ecological systems. Provide decision support including web based guidance and scenarios to assess options;
Take Action: Help communities to develop and implement solutions.

By increasing coastal resilience, TNC believes we can reduce the current and growing risks to coastal communities from natural hazards and climate change through the use of natural solutions and smart development.

This view is supported by a report Resilient Coasts: A Blueprint for Action (April 2009), wherein the Heinz Center and Ceres undertook the challenging task of forging consensus on principles and actions to increase coastal resilience for three fundamental reasons: our coasts are threatened, there are reasonable steps to counter those threats, and we as a nation are not yet taking them. That report noted:

“Reducing the physical and economic risks associated with coastal hazards is not only critical, but is also often cost-effective. An analysis by the National Institute for Building Safety concluded that investments made to minimize impacts from earthquakes, flood, and wind yielded more than four dollars of benefit for every dollar spent. Another study estimated that coastal wetlands in the United States provide $23.2 billion worth of storm protection services each year. The new threats posed by climate change will also require new solutions. We must develop knowledge, tools and approaches for quantifying risk from climate change in a way that allows planners, underwriters and others to formulate and implement adaptation strategies. Improved land use planning and building codes, as well as the maintenance of a strong private insurance marketplace, will be central to the success of any mitigation strategy.”

The report developed a list of Resilient Coast Principles, as follows:

Identify and fill critical gaps in scientific understanding and develop the tools and methodologies necessary for incorporating climate change into risk assessments and risk mitigation decisions.
Require risk-based land use planning.
Design adaptable infrastructure and building code standards to meet future risk.
Strengthen ecosystems as part of a risk mitigation strategy.
Develop flexible adaptation plans.
Maintain a viable private property and casualty insurance market.
Integrate climate change impacts into due diligence for investment and lending.

The principle “Strengthen ecosystems as part of a risk mitigation strategy” is strongly embraced in TNC’s coastal resiliency program.

Natural Coastal Protection is the protection of coastal lands and populations from erosion, inundation and storm impacts by natural systems. TNC and partners are contributing to the body of knowledge and case studies illustrating approaches to natural solutions around the world and improving the science of ecosystem-based adaptation (EBA) through reviews of the scientific literature on how and when ecosystems can help to protect coasts from hazards.

Even the U.S. Army Corps of Engineers now acknowledges the importance of coastal resilience and the value of including natural or nature-based features (e.g., wetlands and dunes) in their portfolio of approaches that can be used to reduce the risks associated with coastal hazards.

As noted above, coastal development and adaptation policies that consider social, economic and environmental risks simultaneously can reduce social and economic vulnerability and maximize the risk reduction benefits that natural habitats can provide.

As part of their coastal resiliency project, TNC works to promote the role of natural ecosystems in reducing climate and disaster risks. They are working with partners at local and global levels to:

Demonstrate where, when and how healthy or restored coastal ecosystems can contribute to cost-effective solutions that address current and growing risk from natural hazards and climate change;
Provide communities, developers and government planners with the knowledge and tools to make decisions and take actions to reduce risks and enable climate-resilient development;
Develop the partnerships and political will needed to promote the use of effective natural solutions in adaptation and disaster risk reduction.

For each major coastal habitat—coral reefs, oyster reefs, mangrove forests and salt marshes—TNC is documenting and quantifying the risk reduction benefits that these habitats can provide. By developing the same information about habitats that engineers provide about sea walls and other built defense structures, this effort will analyze and identify when and where coastal ecosystems are effective for reducing the risks from natural hazards.

With the interactive decision-support framework, users can visualize future flood risks from sea level rise and storm surge. They can also identify areas and populations at risk and gain a better understanding of ecological, social, and economic impacts from coastal hazards. This information is particularly helpful for officials taking rising sea levels and increased storm intensity and frequency into consideration when making coastal management decisions—such as coastal planning, zoning, and land acquisition. The Coastal Resilience Framework is being advanced in many geographies:

New York and Connecticut
Gulf of Mexico
Florida Keys
Puget Sound
Southern California
U.S. Virgin Islands

Case Studies

Case studies have been developed to illustrate the applicability and benefits of using coastal resilience to address the threats of sea level rise and coastal hazards. Two such case studies are in Connecticut and Long Island.

Bridgeport, Connecticut
After living through several coastal hazards events over the course of only a few years—tropical storm Irene and a nor’easter in 2011, and a tornado in 2010—the City of Bridgeport, Connecticut, looked to better prepare for disasters. This was before Hurricane Sandy struck the community, carrying an unprecedented 13-foot storm surge.

Though Sandy caused flooding in vulnerable areas throughout the city, Bridgeport had a head start in identifying risks, vulnerabilities, and strengths. In the months before the storm, The Nature Conservancy and Clean Air‒Cool Planet, with local partners such as the Greater Bridgeport Regional Council and Regional Plan Association, held climate preparedness workshops using NOAA’s Roadmap for Adapting to Coastal Risk and The Nature Conservancy’s Coastal Resilience Decision Support Tool. The goal was to advance a conversation on risk, choices, and actions the community could take to reduce risks and increase resilience. The workshops integrated maps showing potential flooding from extreme events and sea level rise into a community-driven process and dialogue through which the community identified top hazards and priorities for action.

Bridgeport’s top three identified hazards—coastal and inland flooding, storm surge from tropical storms and hurricanes, and rising seas and groundwater levels—were affirmed by Sandy’s impact. Despite Sandy’s punch, the community had a head start in its path to resilience. Now, as residents rebuild, Bridgeport is working to update its Natural Hazard Mitigation Plan and enroll in the Federal Emergency Management Agency’s Community Rating System, which offers private property owners reductions in National Flood Insurance Program premiums in return for community-wide hazard mitigation and risk reduction. Other priorities include adjusting building codes and land use policy, incorporating nature-based solutions such as marsh advancement zones and green infrastructure for managing storm water, and factoring climate change into redevelopment and infrastructure plans.

Long Island, New York
The shores of Long Island, New York, have highly developed lands in the coastal zone, much of it only inches above sea level. Long Island stakeholders have indicated a need to visualize and understand how they can make informed planning, zoning, acquisition, and permitting decisions that will increase the area’s resilience to coastal hazards in the short and long terms.

TNC’s Coastal Resilience project addressed these issues by compiling social and natural resource data, inundation scenarios, and spatial analysis results in an interactive Web mapping tool. Decision makers can use this tool to assess alternative future scenarios that address sea level rise, storm surge, and community vulnerability.

The report Local Land Use Response to Sea Level Rise, prepared by the Land Use Law Center, Pace University School of Law as part of this case study, summarizes selected local land use ordinances and regulations that include specific mention of sea level rise or that incorporate appropriate policy responses that may be used to address sea level rise. Specific recommendations in this approach include the following:

Amending key laws
Planning for and implementing smarter, safer post-storm redevelopment
Acquiring land in harm’s way
Restoring habitats that provide protection
Moving vulnerable public structures

Howard Beach, Queens
An additional, more specific case study in New York was prepared by TNC by request from the New York City Special Initiative for Rebuilding to evaluate the role of nature and natural infrastructure in protecting coastal communities in New York City from some of the impacts of climate change. The community of Howard Beach, Queens, an area that was hard hit during Hurricane Sandy, was selected as a representative neighborhood for conceptually addressing the use of natural systems as part of a resilience strategy in the face of a changing climate and future storm events.

The highlights of the study found:

Natural features can be successfully used in a dense urban setting, in combination with “built” defenses, to provide efficient and cost-effective protection from sea level rise, storm surges and coastal flooding, and;
Innovative financing options are available to bring these hybrid approaches to reality.
Also, in preparing this case study, one of the important conclusions reached was that community participation—which was outside the scope of this conceptual study—is a necessary ingredient for any future work aimed at developing solutions for particular communities.

TNC's analysis looked at natural defenses like re-vegetated shorelines, mussel beds and restored wetlands, and also at more traditional, built defenses like removable sea walls and sea gates at the entrance to some of Howard Beach’s canals. Our experts studied a variety of scenarios to determine what would be most effective, what costs and financing might look like, and how this might all look long-term.

The report found that the hybrid approaches, combining natural and built options, could work effectively in dense urban areas to provide climate protection as well as other benefits for communities. We found that once you start mixing natural and built defenses, you start seeing great returns on residential properties. Although it may seem like the only way to protect a dense urban area is with built infrastructure, our study demonstrates that there is a significant, cost-efficient role for nature to play.

Here are additional case studies from New Hampshire, Texas and more.

A related but more broadly-applicable concept is Climate Resilience.