# New research shows what’s at stake when wetlands disappear  *Published:* 2026-06-01 *Author:* Morgan Bomer **From a North Carolina field visit to a national map of flood patterns, new research shows wetlands reduce flood damages, and losing them has increased insured losses** *This blog post was co-authored by [Jesse Gourevitch](https://www.linkedin.com/in/jesse-gourevitch-85513137/), former EDF Economist, and* [*Adam Gold*](https://www.edf.org/people/adam-gold)*, Senior Manager, Climate Resilient Coasts and Watersheds Science.* On a recent field visit in coastal North Carolina, state lawmakers saw two very different landscapes. One was an intact wetland—a mostly wet habitat, home to unique soils and water-loving plants. Wetlands can hold stormwater, slow runoff, and help reduce the flow of floodwaters downstream during heavy rain. The other was a neighborhood with upstream wetlands loss that has experienced frequent flooding. That contrast illustrates the central findings of our [new study](https://www.nature.com/articles/s44221-026-00656-3), published in *Nature Water*: wetlands reduce flood damages, and losing them has real costs for people and communities downstream. In [our study](https://www.nature.com/articles/s44221-026-00656-3), we found that wetland loss across the United States has increased residential flood insurance claim payments nationwide by an estimated **$10.1 billion** since 1985, equal to about **9.0% of insured riverine flood** losses. The highest added costs were concentrated in the Houston metropolitan area, southeastern Louisiana, and coastal Florida. Because the National Flood Insurance Program, or NFIP, [covers only a fraction](https://www.nature.com/articles/s41558-025-02396-w) of total flood losses to homes, the full costs of wetland loss are likely even higher. For policymakers weighing land use decisions, wetland protections, conservation investments or flood insurance pricing, that number helps answer a question that has long been difficult to quantify: What is the economic value of wetlands in reducing flood damage to homeowners? [![](https://blogs.edf.org/markets/wp-content/blogs.dir/32/files//55180672595_61cc8ca177_k-copy-1024x683.jpg)](https://blogs.edf.org/markets/wp-content/blogs.dir/32/files//55180672595_61cc8ca177_k-copy.jpg)> *As flooding becomes more frequent and severe, communities need reliable information about what reduces flood risk and what makes it worse,”* said Jesse Gourevitch, former economist at EDF and lead author of the study. **Wetlands are natural infrastructure** Wetlands are sometimes described as “natural sponges.” During heavy rain or major storms, they are vital to storing floodwaters and slowing its movement across the landscape. Land cover changes have consequences across watersheds, and changes to wetlands upstream can have significant downstream effects when storms hit. As we approach the beginning of hurricane season, this protection is especially critical. In our study, we looked at how the loss of wetlands upstream affects downstream riverine flood losses to residential properties. Using individual National Flood Insurance Program (NFIP) claims, local rainfall data and changes in wetland area across the country, we found that flood insurance claim payment amounts for individual residential properties increased by an average **0.01% to 0.03% per hectare of upstream wetland loss**. That may sound small at first glance. But across thousands of places and decades of wetland loss, it adds up quickly. **Wetlands’ value goes far beyond flood mitigation** It is important to emphasize that this study measures only one part of wetlands’ value: reducing insured riverine flood losses to residential properties. Wetlands also provide many other benefits, including improving water quality, storing carbon, supporting wildlife habitat and creating recreational opportunities. Our analysis also does not include many other categories of flood damage, such as losses to commercial or government property, business interruption, uninsured losses or flooding from coastal storm surge. So while the study’s core estimate is significant, it is also conservative. We also found that the burden of wetland loss is not shared equally. Historical wetland loss disproportionately increased flood damages in **lower-income communities** and communities with higher shares of **non-white residents**. **Why the NFIP connection matters** Our study uses claims data from the National Flood Insurance Program (NIFP), which underwrites 90 – 95% of flood insurance policies in the United States. That makes NFIP claims one of the clearest nationwide datasets available for observing flood losses to individual households over the last 40 years. By linking wetland loss to NFIP claim payments, we were able to quantify one especially concrete part of wetlands’ economic value: their role in reducing insured riverine flood losses to residential properties. That matters to policy. Our findings can help inform federal benefit-cost analyses, state land use and wetland policy, conservation investments and flood insurance pricing. [![](https://blogs.edf.org/markets/wp-content/blogs.dir/32/files//Wetlands-infographic-02-051526-1024x576.png)](https://blogs.edf.org/markets/wp-content/blogs.dir/32/files//Wetlands-infographic-02-051526-scaled.png)**A national study that can be explored locally** Wetland loss does not affect every community in the same way. In some places, losing even a small amount of wetland can significantly increase flood damage downstream. In others, the effect is smaller. To reflect that, we estimated the value of one hectare of wetlands in reducing flood damages to residential properties for each sub-watershed in the U.S. We found that the average value of wetlands for reducing residential flood losses is $15,738 per hectare of wetlands. In the top 10% of sub-watersheds, the value of wetlands is greater than $24,783, and in the top 1% of sub-watersheds, that value exceeds $301,268 per hectare. We also found that in 16% of sub-watersheds, the benefits of protecting wetlands for residential flood mitigation alone would outweigh the costs of conservation. And because wetlands provide many other benefits beyond flood reduction, the number of places where protection makes economic sense is likely much higher. State and local leaders and policymakers can explore these findings in our [interactive web map](https://www.edf.org/maps/wetlands-flood-reduction/), which allows users to zoom in on specific watersheds and see where wetlands provide the highest flood protection benefits and where future wetland loss could create especially high downstream costs. [![](https://blogs.edf.org/markets/wp-content/blogs.dir/32/files//Flooding_of_the_Guadalupe_River_near_Kerrville_Texas_in_2025-copy-1024x771.jpg)](https://blogs.edf.org/markets/wp-content/blogs.dir/32/files//Flooding_of_the_Guadalupe_River_near_Kerrville_Texas_in_2025-copy.jpg)Developed areas that have experienced flooding illustrate what may be at stake when wetlands are filled or degraded upstream.> *“Wetlands act like natural sponges during heavy rain, storing floodwater and slowing runoff before it moves downstream,”* said Adam Gold, senior manager of coasts and watersheds science at EDF and co-author of the study. *“Yet wetlands continue to disappear, in part because the value of the services they provide is often overlooked. Our analysis helps fill that information gap.”* **What this means for policy** Wetland policy is often debated in legal, regulatory or land use terms. Our goal was to provide empirical evidence that shows what these decisions mean for people living downstream. The study also provides critical details that could inform the new federal definition of “Waters of the United States” (WOTUS) being proposed by the Trump Administration. In 2023, a majority opinion by the U.S. Supreme Court *(Sackett v EPA*) drastically scaled back federal protections for America’s nontidal wetlands, threatening the communities and ecosystems that depend on them for critical habitat and flood protection. Now, if [the Trump Administration new rule that would require a wetland to have long-term surface water in order to be protected](https://www.science.org/doi/10.1126/science.adp3222), goes into effect, up to 91% of non-tidal wetlands would be considered non-WOTUS wetlands. After accounting for state protections and conserved lands, our new study estimates that these non-WOTUS wetlands without additional protections provide about **$177 billion** in flood mitigation benefits to residential properties alone. [That matters](https://www.edf.org/wetlands) for federal agencies conducting rulemaking and economic analysis. It also matters for states, especially as their decisions about wetland protection may increasingly shape future flood risk and costs. What lawmakers saw in North Carolina offered a simple visual lesson. Our research provides broader evidence behind it. Wetlands are not just open space waiting to be developed. They are part of the infrastructure that helps reduce flood damage. And when they disappear, households and communities bear the burden, and the costs, every time a storm hits. **Explore the interactive map:** [https://www.edf.org/maps/wetlands-flood-reduction/ ](https://www.edf.org/maps/wetlands-flood-reduction/) **Read the study in *Nature Water*:** **Read the press release:** [https://www.edf.org/media/new-study-shows-wetlands-loss-has-increased-residential-flood-insurance-claim-payments-10 ]()