Flood Risk is Not Equal: Considering Social Vulnerability in Vermont Flood Mitigation

Vermont has faced significant flooding events in recent years, including Tropical Storm Irene in 2011, the Great Vermont Flood of July 2023, and an anniversary event in July 2024. On top of these events, there have also been less extreme summer flooding and winter ice jam flooding. Communities across the state have been hit hard by flooding, and some are still recovering. As climate change progresses, Vermont can expect to experience more frequent and intense flooding, making flood mitigation efforts more important than ever.

Social vulnerability describes how socioeconomic factors may contribute to the vulnerability of individuals, groups, or communities to natural hazards. Research suggests that communities that face increased social vulnerability are more often at risk of experiencing natural hazard events, especially flooding. One reason for this is that properties located in flood-prone areas typically have lower values, making them more affordable for low-income groups. As a result, those who experience high social vulnerability may also have a more difficult time responding and recovering from flooding events (Tate et al., 2021). These difficulties stem from barriers in societal resources and differences in capacity to respond and recover from flooding hazards.

To understand Vermont’s risk of flooding, a study was conducted at the University of Vermont to explore the intersections between social vulnerability and flood risk. The objective of the research was to identify communities in Vermont that face high social vulnerability and are at risk of flooding to inform state flood mitigation strategies. The researchers did this by mapping social vulnerability with existing data, mapping flood risk with inundation model outputs and drone imagery and then identifying the intersections of these data.

The study also used an advisory board to incorporate expert opinions. The advisory board members included state floodplain managers, individuals involved with Vermont Emergency Management, members of a long-term resource recovery group, and academics. This group was used to ground-truth the study results throughout the project based on their working knowledge of flooding impacts in the state. In addition, a focus group was held with a town that was identified in the study to experience high social vulnerability and risk of flooding. This focus group was held to learn about how well the study captured community members’ lived experience, and their perceptions of flood risk.

Flooding can have devastating and diverse impacts on communities, which makes it difficult to know what the right solution is. The study developed a method to help decision makers identify candidates for state-level flood mitigation. The research team identified what they called Vulnerable Frontline Vermont Communities, which maps Vermont towns that face high social vulnerability and are at risk for flooding. The researchers included the top 10% of Vermont towns that face high social vulnerability and are at risk of flooding. The team developed two versions of the Vulnerable Frontline Vermont Communities, with one including flood risk to buildings, and the other not including buildings. The researchers suggest prioritizing the identified communities in flood hazard mitigation efforts in the state.

Many of the Vulnerable Frontline Vermont Communities are in the Northeast Kingdom, the northeast corner of Vermont. This suggests that resources to respond to floods in this region may be low, and that towns in this region may be strong candidates for mitigation efforts. Towns that were identified as Vulnerable Frontline Vermont Communities often had high social vulnerability scores for the indicators ‘Rentership’ and ‘Housing Cost Burden.’ These indicators are therefore focus points that can help increase the capacity of towns to respond to flooding if changed. For example, towns with high scores in the ‘Rentership’ indicator may benefit from increased availability of short-term housing after flood events.

Research like this can help inform emergency managers, and flood resiliency stakeholders in Vermont about where there are communities who would benefit from flood mitigation efforts but may not have the resources or capacity to complete these efforts without support. This work aims to help build a more flood-resilient Vermont and ensure that all Vermonters can become more resilient to future flooding in the face of climate change. An interactive StoryMap which looks at the key research findings, and Vulnerable Frontline Vermont Community identifications will become available in the future. The StoryMap will additionally provide a roadmap for future work that will allow emergency managers, flood resiliency stakeholders, and communities to operationalize these data.

Data from this study are publicly available and can be accessed on the Forest Ecosystem Monitoring Cooperative repository.