How Nature Can Help Reduce Impacts of Flooding
The severity and impacts of coastal storms and flooding are getting worse. Reducing the risks that storms pose always involves multiple solutions working in tandem. These solutions include: early warning systems; manmade or “built” solutions like reservoirs, dams, levees, seawalls and pumps; working with willing communities and homeowners to move people out of areas that are subject to frequent flooding, and nature itself.
There is arole that nature itself can playin helping reduce flood risk for communities while providing other benefits, like improved water quality and enhanced recreational opportunities and wildlife habitat, all of which can also enrich local economies. Such “nature-based solutions” or “natural infrastructure” are important as part of a holistic approach to coastal resilience.
But to be effective, our natural systems need good water quality so that they can be healthy and resilient.
Science Shows that Marshes Reduce Property Losses
A study commissioned by The Nature Conservancy showed that coastal wetlands in the northeastern U.S. prevented $625 million in property damages from flooding during Hurricane Sandy. The study also showed that these same wetlands reduce annual storm damage by at least 15 percent. There are many cost-effective and sensible ways to finance natural infrastructure for coastal flood damage reduction and support the re-building of coastal resilience.
Currently, less than 3 percent of funding currently goes to natural infrastructure as opposed to “grey” or “built” infrastructure. This is a coastal investment portfolio that should be re-balanced, especially when funds are made available for rebuilding after major storms.
Dunes Provide Protection at South Seaside Park, N.J.
In December 1992, a Nor’easter caused significant flooding and erosion at South Seaside Park, in part because naturally occurring dunes there had been removed years before to improve ocean views and beach access. After the 1992 Nor’easter the community used snow fencing to help rebuild the dunes and then stabilized them by planting dune grasses. When Hurricane Sandy hit in 2012, the dunes were 25 feet high and 150 feet wide. During the storm, these dunes protected the community from severe damage and flooding along the ocean front. The dunes, rather than homes, businesses and infrastructure, took the brunt of the storm.
South Seaside Park also serves as acase studyfor theNaturally Resilient Communitiesprogram, which is a partnership of county governments, professional engineers, community planners, floodplain managers and conservationists who work with communities to improve their quality of life and economies through the use of nature-based solutions.
Beaches and Wetlands Reduce Flood Damage at South Cape May, N.J.
At the 200-acre South Cape May Meadows Preserve, The Nature Conservancy has worked with partners to restore wetlands and sand dunes that have helped protect the neighborhood located behind them from the impacts of several storms, including Hurricane Irene in 2011 and Sandy in 2012. This natural infrastructure protected Cape May Point during Hurricane Sandy against the third highest storm surge experienced since Hurricane Gloria in 1985. The restored wetland absorbed nearly 10 inches of rainfall—also the highest recorded since 1985—resulting in minimal damage to nearby neighborhoods.
In 2014, Conservancy scientists produced an analysis of the economic and social benefits of the ecological restoration at South Cape May. They found that the restoration helped reduce the average flood damage per storm from $143,713 to $3,713 (for the same level of storm surge). During Sandy, nourished beaches on New Jersey’s Atlantic Coast reduced the likelihood of severe damage or destruction to “first row” homes and businesses by 50 percent.
Nature’s Strength Depends on You
Nature can be a big ally in helping to protect us against coastal storms. But nature also depends on us to keep it healthy. You can help keep our marshes (and other habitats) healthy by limiting your use of fertilizers, pesticides and herbicides that runoff and harm wetlands and marshes.