Eastern hemlock.
A Powerful Pump Trees' ability to capture, store and remove water from the environment could make them a key player in the fight against flooding. © Kent Mason


New study to measure flood-reduction benefits of Virginia Beach forests

Virginia Tech scientists will conduct the commissioned study examining how the City’s forests may mitigate urban flooding

In an effort to better understand the role forests play in reducing local flooding, a new study will be conducted by Virginia Tech’s Department of Forest Resources and Environmental Conservation to examine how forests capture, store, and remove rainwater and runoff. 

The study has been commissioned by the City of Virginia Beach, The Nature Conservancy, Lynnhaven River NOW, and the Virginia Department of Forestry, with additional in-kind technical support to be provided by the Dewberry engineering consulting firm.

The City of Virginia Beach, facing increasing frequency and severity of flood events, is investigating how “green” infrastructure such as forests might play a role in stormwater and flood management.

The study’s backers hope to use the data to determine which local forests already provide significant flood risk reduction benefits and thus are priority forests for conservation, as well as locations where potential reforestation might be most strategically employed.  VA Beach Director of Agriculture David Trimmer and Councilwoman Barbara Henley are spearheading the effort for the city.

Said Councilwoman Henley: “Clearly, our forests play an important part in flood management.  This research will help us better identify that benefit, and how we can maximize the role that our forests can play in reducing local flooding.  We have so much to learn, and this project should be one that our citizens can follow and appreciate.  It is exciting to get this work underway, and to take some real steps toward addressing this issue which is so critical for all of us.”

The study will be conducted in two phases.  Phase one will analyze current flood reduction services provided by the city’s forests, and how these services may depend on forest attributes (tree density, leaf area, soils) and their adjacency to flood prone urban areas. With this information, the study will estimate how much water is stored and removed by forests within the jurisdictional boundaries of Virginia Beach (approximately 497 square miles). 

The future second phase will build upon this work to incorporate these estimates of forest flood reduction into computer models that can simulate water storage and runoff during specific rain events. This second phase will also develop a user-friendly, interactive platform to assess different scenarios of forest conservation and restoration strategies.  The work aims to provide a comprehensive evaluation and tools to assist city officials in targeting high-performing forests for conservation and other locations for reforestation.

 “Forests are effective at both soil water storage and water use through plant uptake,” said lead VA Tech scientist Daniel McLaughlin. “Together, these forest processes help to capture and remove incoming rainfall, thereby reducing stormwater runoff to adjacent flood prone areas.  This study seeks to quantify these flood reduction functions and, in doing so, help inform forest conservation and restoration efforts as part of green infrastructure strategies for stormwater management. We see this work as an important step in new initiatives to incorporate urban forests into stormwater planning. Our end goal is to provide an approach and new user-friendly tools to inform forest management in both Virginia Beach and other flood prone areas in the region.”

The data collection for the first phase of the study is expected to be completed in March with a report on the findings to be released in June.  Phase two of the study will begin subsequent to that, but an exact start date has yet to be determined.

“The many benefits Virginians receive from forests are remarkable, but in communities like Virginia Beach where stormwater management and flooding present additional challenges they play an even more important role than many people realize,” said Locke Ogens, State Director for The Nature Conservancy in Virginia. “This study will give us critical new data on how forests, including 3,680 acres owned by The Nature Conservancy in Virginia Beach as part of the North Landing River Watershed, are already protecting the city and what additional protection an expanded forest canopy could provide.  As Virginia’s coastal communities grapple with how to best prepare for future flood events, it’s crucial that we recognize the important role natural features can play in making our state more resilient.”

“Lynnhaven River NOW is pleased to be a part of this important study,” said Lynnhaven River NOW Executive Director Karen Forget. “As we move forward with planning for sea level rise and increased flooding, this study will provide the information we need to add strategic forest conservation and reforestation to our toolkit.”

“The VDOF is excited to support yet another initiative to demonstrate the vital role trees and forests can play in addressing issues facing Virginia communities. Forests and trees support rural economies, provide clean air and water and form the backdrop for a scenic Virginia,” said Virginia State Forester Rob Farrell. “From rural forests to city trees, the VDOF understands that trees are the answer.”

The Nature Conservancy is a global conservation organization dedicated to conserving the lands and waters on which all life depends. Guided by science, we create innovative, on-the-ground solutions to our world's toughest challenges so that nature and people can thrive together. We are tackling climate change, conserving lands, waters and oceans at an unprecedented scale, providing food and water sustainably and helping make cities more sustainable. Working in 79 countries and territories, we use a collaborative approach that engages local communities, governments, the private sector, and other partners. To learn more, visit www.nature.org or follow @nature_press on Twitter.