The U.S. Federal Emergency Management Agency (FEMA) assists communities as they prepare for, respond to, or recover from, natural disasters. Natural disasters are increasing in frequency and severity, driven in part by climate change and steadily growing development in hazard-prone areas. Since 1980, the US has experienced over 300 weather and climate disasters that have each reached or exceeded $1 billion in damages, with total costs over $2.195 trillion and counting. As the costs of disaster responses has risen, FEMA has come to recognize the importance of nature-based solutions in community resilience as viable alternatives which provide ecosystem service co-benefits.

Since 2013, we have supported FEMA as it has incorporated ecosystem service benefits of nature-based solutions into its Benefit-Cost Analysis Toolkit for hazard mitigation assistance applicants. This includes updates to FEMA’s baseline ecosystem service valuation estimates in 2016, 2020, and 2022, which expanded the variety of eligible landcover and green infrastructure project elements. The inclusion of ecosystem services in benefit-cost analyses improves the economic performance of nature-based solutions, increasing the competitiveness of such projects.

Earth Economics and FEMA: a timeline

FEMA defines ecosystem services as “direct or indirect contributions that ecosystems make to the environment and human populations,” reducing disaster risk through water infiltration, erosion control, improved air quality, and more, while also benefiting local ecosystems and nearby and downstream communities.

2013

LANDCOVER TYPES: 2 | NUMBER OF VALUES: 17

FEMA issued its first ecosystem services policy (FP-108-024-01), allowing the use of ecosystem service benefits in acquisition projects that demonstrate a benefit-cost ratio of 0.75 or greater. Earth Economics developed the framework and ecosystem service values for riparian and green open space landcover categories in the BCA Toolkit.

2016

LANDCOVER TYPES: 5 | NUMBER OF VALUES: 29

Earth Economics developed ecosystem services values for three new land cover categories (wetlands, forest, and marine and estuary) and updated values for landcover categories already in the BCA Toolkit. FEMA expanded eligibility to the following activities: floodplain and stream restoration, green infrastructure, post-wildfire mitigation, and aquifer storage and recovery.

2020

LANDCOVER TYPES: 5 | NUMBER OF VALUES 29

FEMA released a significant policy update (FP-108-024-02), removing the 0.75 benefit-cost ratio threshold requirement for inclusion of ecosystem services values in a benefit-cost analysis. The meant that nature-based hazard mitigation projects could now be considered cost-effective based on the balance of project costs and ecosystem services benefits alone.

2022

LANDCOVER TYPES: 9 | NUMBER OF VALUES: 59

Earth Economics supported a third update to the BCA Toolkit values, including new landcovers (coral reefs, shellfish reefs, and beaches and dunes), reorganizing prior landcovers into green open space and inland and coastal wetlands, added 22 new individual ecosystem services across all land cover types, increasing the value of benefits provided by many landcover types.

GREEN INFRASTRUCTURE TYPES: 4 | NUMBER OF VALUES: 23

Earth Economics worked with FEMA to include nine economic benefits for four green infrastructure types (street trees, pervious pavement, bioretention, and green roofs).

fema’s latest additions to the bca toolkit

In 2022, FEMA expanded the variety of landcover types supported in its BCA Toolkit, which now include forests, green open space, riparian areas, wetlands, coral reefs, shellfish reefs, and beaches and dunes. Earth Economics developed the valuation estimates for these new landcover categories (and updated estimates for those already included in the BCA Toolkit).

Coral reefs are hardened and fixed structures created by the deposition of calcium carbonate by marine coral species. They provide aesthetic and recreational value, offer critical habitat and support for marine species and their food webs, and help to limit inland erosion and flooding by reducing the force of ocean waves. FEMA considers the annual value of these ecosystem services to be $7,120 for every acre of reef.

Shellfish reefs are areas dominated by living or non-living shell reefs, surrounded and intermixed with channels and unvegetated flats, typically occurring in intertidal zones. They support local food webs, improve water quality by filtering and processing wastes, and support recreational activities. FEMA considers the annual value of these ecosystem services to be $2,757 for every acre of shellfish reef.

Beaches and dunes are coastal areas of silt, sand, or gravel that are subject to flooding and redistribution due to water or wind. They tend to lack vegetative cover except for plants that are briefly established when growing conditions are favorable. These ecosystems provide immense aesthetic and recreational value—FEMA considers the annual value provided by these ecosystem services to be $300,649 per acre.

REPORT: FEMA ECOSYSTEM SERVICE VALUE UPDATES

FEMA began to recognize and emphasize the value of investing in Nature-Based Solutions for mitigating the impacts of floods, wildfires, droughts and other natural hazards. NBS landcover types include wetlands, trees, open green space, and other forms of green infrastructure that help to protect vulnerable communities, thus reducing costs to taxpayers. Studies have shown that NBS can often be more cost-effective than engineered solutions, while providing additional community and environmental benefits.

This report provide details on an updated set of landcover categories and ecosystem service values for the BCA Toolkit. Key changes include an expansion in the number of landcover categories, and new source studies for the values associated with all landcover categories. This report also includes guidance on how to interpret and use these landcover categories in the context of a benefit-cost analysis for nature-based mitigation projects, with examples.

 

factsheet: ECOSYSTEM SERVICES VALUES IN FEMA’S HAZARD MITIGATION PROGRAM

Since 2013, Earth Economics has worked closely with FEMA to integrate ecosystem services into its benefit-cost analysis framework and providing valuation estimates for its BCA Toolkit. Our ongoing partnership has more than tripled the number of ecosystem service values in the BCA Toolkit and extended their application to all FEMA project types. Earth Economics updates to the BCA Toolkit incorporate the latest, and best-quality literature on ecosystem services valuation to further ensure that nature is valued in FEMA decision-making.

The 2022 updates added 22 valuation estimates for a total of 59 landcover-ecosystem services value combinations, modified earlier estimates for green open space (urban and rural), as well as inland and coastal wetlands, added 3 new landcover types (coral reefs, shellfish reefs, and beaches and dunes), added 50 new supporting studies to support these valuations, and overall increased $/acre/year estimates fourfold (on average).

GREEN INFRASTRUCTURE

Green infrastructure (GI) refers to nature-based solutions sometimes known as green stormwater infrastructure (GSI) or urban green infrastructure, defined in the Water Infrastructure Improvement Act of 2019 as measures that use plant or soil systems, permeable surfaces or substrates, or landscaping to infiltrate and store of stormwater, reducing runoff to sewer systems or to surface waters.”

It has becoming increasingly common to use GI in urbanized areas for stormwater management and hazard mitigation, typically in the form of raingardens, swales, vegetated filter strips, permeable pavements, green roofs, stormwater tree pits, and rainwater harvesting. These tend to have relatively smaller footprints than other nature-based solutions, and are often engineered and sited to maximize stormwater management and other community benefits.

Green roofs are partly or completely covered with growing medium and vegetation planted over waterproof membranes. They often include root barriers and both drainage and irrigation systems. The soils and plants integral to green roof designs improve property values, capture and retain stormwater, provide bird habitat, reduce building energy use (by providing both insulation and evapotranspiration) and associated emissions, sequester and store carbon, and improve air quality. FEMA estimates the annual value of these benefits at $0.40 per square foot.

Urban trees are trees (and sometimes larger perennial bushes) growing within urbanized areas. They are a powerful means of reducing extreme heat, energy demand, and associated emissions (through shading and evapotranspiration), but they can also improve property values, capture and retain stormwater, provide bird and wildlife habitat, sequester and store carbon, and improve air quality. FEMA estimates the annual value of these benefits at $1,055 per tree.

Bioretention features are landscaped areas such as raingardens and swales that absorb and treat stormwater runoff from impervious surfaces such as roofs, driveways, sidewalks, and parking lots. They are designed to replicate the water absorption and pollutant removal mechanisms of natural systems, reducing runoff and recharging local groundwater. Bioretention features also reduce drought risk, improve property values, provide habitat, sequester and store carbon, and improve air quality. FEMA estimates the annual value of these benefits at $2.84 per square foot.

Permeable pavement allows stormwater to infiltrate into soils, reducing runoff and peak flows to sewer systems and recharging local groundwater. These can take the form of porous asphalt and concrete, and interlocking brickwork design with gaps to enable water passage. Although not technical a nature-based solution, permeable pavement can also reduce drought risk. FEMA estimates the annual value of these benefits at $0.64 per square foot.

REPORT: FEMA Economic Benefit Values for Green Infrastructure

FEMA is increasingly recognizing the value of green infrastructure—green roofs, trees, raingardens and swales, permeable pavement—to store, infiltrate, or evapotranspirate stormwater, reducing runoff to sewer systems and surface waters. Green infrastructure is often contrasted with gray infrastructure—pipes, pumps and storage vessels, but the most effective approaches often combine green and gray infrastructure elements. Studies have shown that green infrastructure can be more cost-effective than gray infrastructure, especially when community benefits are included.

These additional community benefits include improved property values, energy savings, heat reductions, air and water quality improvements, carbon sequestration and storage, habitat, and both improved aesthetics and recreational opportunities. Because green infrastructure features can be planned, designed, and implemented at multiple scales, from individual raingardens to a broad portfolio of across an entire city.

 

FACTSHEET: GREEN INFRASTRUCTURE VALUES IN FEMA’S HAZARD MITIGATION

The 1998 Stafford Act requires all FEMA mitigation projects be cost-effective, as documented by the discounted net present value of each project’s future benefits and costs. In 2022, Earth Economics helped FEMA integrate the ecosystem services benefits of select green infrastructure types into its BCA Toolkit, ensuring that GI projects are being evaluated consistently.

FEMA has multiple Hazard Mitigation Programs, including the Hazard Mitigation Grant Program (HMGP), Building Resilient Infrastructure and Communities (BRIC), and Flood Mitigation Assistance (FMA), which fund activities from planning and design through full project implementation. By supporting inclusion of the co-benefits produced by green infrastructure features, these updates help communities pursuing nature-based solutions to submit proposals that more accurately reflect the full range of community benefits, greatly improving the potential for such proposals to be approved.