PA Environment Digest Blog: Brandywine Conservancy, Partners Release Brandywine Flood Study Report

Tuesday, April 29, 2025

Brandywine Conservancy, Partners Release Brandywine Flood Study Report

On April 29, following an extensive study period, with a series of public outreach meetings and community engagement efforts, the Brandywine Conservancy announced the release of the final report of the Brandywine Flood Study.

Conducted in partnership with Chester County Water Resources Authority and the University of Delaware Water Resources Center, the Flood Study was launched in August 2023 in response to more frequent and extreme flooding events impacting communities along the Brandywine Creek in both Pennsylvania and Delaware.

This coordinated effort sought to better understand where and why flooding occurs in our watershed in order to identify the best approaches to protect our communities during future severe flooding events.

The Flood Study team conducted a broad analysis of flood risk in the Brandywine watershed, assessing impacts during intense storm and flooding events—including historic flooding, projections for future floods, and potential impacts of future precipitation, storm events, and land use based on the watershed’s projected population in the year 2100.

The study area encompassed the mainstem of the Brandywine Creek, including key tributaries in Chester and Delaware Counties in Pennsylvania and downstream to impacted areas over the Delaware state line.

The final report includes a summary of the community outreach, data collection, and analyses conducted over the study period, along with an actionable suite of proposed flood mitigation recommendations throughout the watershed, presented in two distinct categories: structural and non-structural improvements.

“Anywhere there is water, there is the potential for flooding. Even with unlimited financial and technological resources, it would be impossible to eliminate all flood risks,” said Grant DeCosta, Director of Community Services for the Brandywine Conservancy.

“Despite those limitations, the Flood Study partners are confident that implementation of the structural and non-structural recommendations laid out in this report can meaningfully reduce future flood risks to communities throughout the Brandywine watershed, and—most importantly—help prevent future loss of life.”

Of the recommendations laid out in the report, structural mitigation measures are often the most visible, like the five major flood control dams and reservoirs that were built after extreme flood events during the early- and mid-20th century, which collectively provide over six billion gallons of flood storage capacity.

Study partners analyzed numerous structural project opportunities, including upgrades to existing flood control infrastructure, bridge and culvert replacements, low-head dam removal, floodplain restoration, and stormwater basin retrofits.

Ultimately, of the more than 300 individual sites evaluated, 16 were prioritized for their potential to reduce regional and localized flood risks, including 10 bridge replacements, four low-head dam removals, one floodplain restoration project on the Brandywine Conservancy & Museum of Art’s campus, and upgrades to the existing Barneston Dam flood control structure in Chester County.

“The Brandywine Flood Study serves as a starting point for addressing the needs of the communities in the Brandywine watershed to prepare for, react to, and reduce the long-term impacts of the next and all future floods,” said Seung Ah Byun, Executive Director of the Chester County Water Resources Authority.

“Potential improvements vary in terms of scale, complexity, capacity, and expense, but each can play a role in mitigating the impacts of flooding in local communities in both Pennsylvania and Delaware.”

More than a dozen non-structural recommendations related to emergency planning, early warning systems, public education campaigns, and more robust road closure measures are also included in the report.

For developed areas within the 100-year floodplain, the report outlines strategies for enhanced floodplain management, flood insurance, and structural elevations, floodproofing, and voluntary buyouts.

The Study also calls for increased land preservation to ensure the long-term functionality of natural floodplains and open space, which act as sponges during storm events.

All of the implementation recommendations include both collaborative action and individual stakeholder projects.

“The Brandywine Flood Study is an important component of broader, multi-faceted efforts currently being undertaken by a variety of non-profit, government, academic, and private organizations to address flooding and its impacts on the communities in the Brandywine Creek watershed,” said Gerald Kauffman Jr., Director of the University of Delaware Water Resources Center.

“Achieving full implementation of this study’s potential will require engagement and collaboration from stakeholders throughout the watershed.”

The Brandywine Flood Study partners are committed to supporting the implementation of these strategies and to continue evaluating new opportunities to reduce localized and regional flooding in the future.

The Brandywine Flood Study was funded, in part, through grants from FEMA, PEMA, Chester County Government and Delaware County Council.

Multiple project partners contributed to the study, including the Stroud Water Research Center, West Chester University, and Meliora Design.

In addition, a Technical Advisory Committee was convened to include additional government officials, nonprofit organizations, and private entities.

Robust public and stakeholder engagement was a priority of the study. This was achieved through sustained efforts to engage the public and ensure that its input informed the technical flooding analyses.

There were diverse engagement options, including over 35 public meetings, listening sessions, and forums; over 1,500 public interactions; an online public survey; an interactive flood mapper; a media/communications toolkit; and a comprehensive project website.

Additional analysis of mitigation projects is currently underway throughout the watershed through ongoing studies in the Cities of Coatesville and Wilmington and in Downingtown Borough.

These complementary efforts will likely produce additional approaches and project sites to supplement those identified in the Brandywine Flood Study.

Click Here to view the Brandywine Flood Study report.

Resource Links:

-- Brandywine Conservancy, Partners Announce Launch Of Brandywine Creek Flood Study Following Historic Flooding From Hurricane Ida [PaEN]

-- Arkansas Advocate: President Denies Disaster Aid For Devastating Tornadoes, Flooding, Tells States To Do More

-- AP: Loss Of Federal Resilient Infrastructure Program Spells Disaster For Hundreds Of Communities, Their Projects

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