February 1, 2022

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Wetlands are more than just an ecosystem for some of our favorite wildlife. They provide a long list of benefits for nearby communities, including protection against floods.

As storms become stronger and more frequent, wetlands are becoming more important. In fact, coastal wetlands in the United States provide an estimated $23.2 billion per year in storm protection services. During Hurricane Sandy alone, coastal wetlands prevented $625 million in direct flood damages.

With these benefits in mind, the American Flood Coalition worked with Wetlands Watch to pilot two projects in Virginia based around ecosystem restoration. The two projects were in Hampton Roads, a low-lying, flood-prone region in coastal Virginia, where the Chesapeake Bay meets the Atlantic Ocean. 

In this post, we’ll present key takeaways from these projects and how other communities can use findings to fight flooding with their own shoreline conservation projects.

But first, let’s introduce wetlands and how they protect against floods.  

What are wetlands?

Wetlands are areas that border wet and dry land, existing anywhere where the soil is at least periodically covered by water. Some examples of wetlands include mangroves, marshes, swamps, bogs, and wet prairies. 

But wetlands are not limited to rural, undeveloped areas. Wetlands near heavily populated urban or suburban areas are called urban wetlands. Because of their proximity to communities, urban wetlands are extremely important, protecting people and property against the dangerous impacts of flooding.  

Why wetlands benefit communities

Communities protect and preserve wetlands for a number of reasons:

Wetlands protect properties  

When storm surges hit or heavy rain falls, wetlands act like a sponge, absorbing excess water and sediment. Just one acre of wetland can retain 1–1.5 million gallons of floodwater.

Because of their sponge-like quality, wetlands can protect properties by giving water somewhere to go during a storm. One square kilometer of wetland provides an average of $1.8 million per year in storm protection. Even a 1% increase in the ratio of wetlands to open water can avoid storm damages to homes by $590,000–$792,000. 

Additionally, 15 feet of wetlands can absorb 50% of incoming wave energy, severely limiting damage to communities behind the wetland. 

Wetlands are cost effective and equitable

Wetlands are also a smart move economically. While built flooding infrastructure, like seawalls and levees, requires costly maintenance and repair over time, healthy wetlands can self-repair and keep pace with rising sea levels with little intervention. 

Meanwhile, built infrastructure also requires cost-benefit analyses, which must account for the value of the protected property. Such analyses often benefit wealthier communities, making wetlands and other natural solutions more equitable. 

One study found that coastal habitats protect a greater percentage of socially vulnerable communities in Texas and Florida compared to the state population.

Wetlands provide co-benefits

Wetlands don’t just protect against flooding. They provide a myriad of additional benefits that all communities can enjoy. For example, wetlands improve ecosystem conditions and in turn strengthen the social, economic, and ecological resilience of a community. Specifically, wetlands…

• Preserve natural drainage and recharge groundwater. 
• Treat polluted water before reaching lakes, streams, and other bodies.
• Enhance biodiversity by providing spawning, nesting, and feeding areas for wildlife.
• Reduce mental and physical stress symptoms associated with post-traumatic stress disorder and other stress-related mental illness that can come about after a disaster.

Unfortunately, many areas have historically overlooked these benefits, dredging or draining wetlands in the spirit of urban development. Such activities not only eliminate many of the benefits of wetlands, it also compounds the problem: Rain that falls on a paved road, for example, is much more likely to cause flooding than if it falls on a wetland, which can absorb excess water. 

Meanwhile, rising sea levels, at their current pace, threaten to take out 89% of Virginia’s tidal wetlands by 2080. In the Chesapeake Bay, the combination of wetland loss and sea level rise, will cause significantly more property damage and affect more people than sea level rise alone.

But with the right planning and projects, communities can help soften the blow of increasing extreme weather and rising seas, setting up themselves for a more resilient and protected future. 

How wetlands prevent flooding in practice

In September 2020, the American Flood Coalition selected Virginia-based environmental and advocacy organization Wetlands Watch as one of its 2020 Flooding Solutions Grantees. 

For the grant, Wetlands Watch employed innovative land-use strategies in two cities in coastal Virginia, Chesapeake and Norfolk. The projects explored how the combination of buyouts, conservation, and market-based tools could reduce flood risk and benefit landowners and communities. 

Specifically, Wetlands Watch is working with an urban land trust, called the Living River Trust, to help communities manage land most threatened by sea level rise and flooding. Land trusts are nonprofit organizations that conserve land, typically through legal agreements that permanently limit land uses. 

• In Chesapeake, Wetlands Watch negotiated approval to transfer full ownership of FEMA buyout properties from the city to a land trust, with the goal to turn those bought-out properties into resilient spaces that reduce flooding and offer recreational benefits to the community.
• In Norfolk, Wetlands Watch worked with the city, developers, community members, and a land trust to implement an innovative zoning tool. The tool finances voluntary property buyouts along the shoreline, allowing wetlands to migrate landward at pace with sea level rise.

Below are some key takeaways from the projects, which can serve as best practices for other communities exploring innovative zoning ordinances or using the FEMA Hazard Mitigation program for buyouts. 

Takeaway #1: Be willing to adjust current policies and practices for wetland conservation

In Chesapeake, Wetlands Watch recommended that FEMA Region III (responsible for Pennsylvania, Maryland, Delaware, Virginia, West Virginia, and Washington, D.C.) revise its property deed restriction. The revision would transfer full ownership and maintenance requirements of FEMA-acquired properties from localities to land conservation organizations. 

Increased risk from sea level rise will require more buyouts, which compounds the property management burden on local governments. By transferring FEMA properties to land conservation organizations, this burden can be reduced. Wetlands Watch also advocated for the deed restriction revisions to be considered nationally.

Takeaway #2: Engage community representatives to advance inclusive solutions to ensure sustainability

In Chesapeake, Wetlands Watch developed community outreach plans (with help from local stakeholders) to be incorporated into the city’s future outreach efforts. At the center of this work was a close collaboration and partnership with a local land trust, the Living River Trust. 

To ensure ideas and strategies were vetted by the appropriate experts, Wetlands Watch created a nationwide community of practice of 115 professionals. Over two years, the community of practice hosted small, subject-driven meetings. This pilot work culminated in a virtual symposium of conservation professionals that gave feedback and recommendations on key project templates, policies, and plans.

Takeaway #3: Promote climate adaptive land-use planning and zoning

Wetlands Watch recommended changing Norfolk’s zoning ordinance to allow wetlands to migrate inland to keep pace with sea level rise. The organization also recommended changing zoning laws to encourage property owners, developers, and land trusts to prioritize resilience. 

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The two Wetlands Watch projects are still in progress, but they have already provided lessons and best practices that can serve other communities with tidal wetlands. Although there is no “one size fits all” approach to reducing flooding, outreach and engagement can lead to a strategy that fits each community. 

Meanwhile, AFC will continue working with local innovators to help scale and share flood resilience projects across the country. 

This post was authored by Yasmine Dyson, Senior Strategy Associate, American Flood Coalition; Gian Tavares, Senior Strategy Associate, American Flood Coalition; and Mary-Carson Stiff, Policy Director, Wetlands Watch.