During the past five years, hurricanes, rain bombs and rising seas have inundated large swaths of South Carolina, and flooding has become a top issue — often the top issue — not only in Charleston but in other low-lying communities.
Many cities and counties are tackling this challenge by improving drainage, tightening stormwater rules on new development, examining zoning through the eyes of land elevation and finding creative ways to live with water. But it’s not enough, evidenced in part by much of the public’s understandable hostility toward new development and its threat to make things worse.
There is another tool we can and should bring to the fight: more trees. Last Sunday’s newspaper contained a wake-up call about the important role trees can play in handling stormwater: A detailed analysis shows how the Charleston region’s worsening drainage problems coincided with a building boom that claimed thousands of formerly forested acres.
The Post and Courier’s Rising Waters project analyzed how Charleston County has lost more than 10,800 wooded acres to development during the past three decades, which exacerbates flooding and helps accelerate the impacts of climate change. The figure — pinpointed by the College of Charleston’s Lowcountry Hazards Center using satellite and aerial imagery — reflected a loss of only 2% of the county’s tree cover since 1992, but development still made a big difference.
“The big takeaway is that you’re seeing more water run off the surface that used to be going into the ground and pumped into the trees,” Norman Levine, director of the Lowcountry Hazards Center, told reporter Tony Bartelme. The Charleston metro area is not an outlier: A 2018 U.S. Forest Service estimate indicated American cities lose 36 million trees a year. But tree loss is a greater concern here, given how we’re more flood prone.
We’ve long appreciated trees because they add beauty and help cool us down, not only by providing shade but also through transpiration. But now that it’s becoming increasingly clear how they also can help keep us dry — a 2017 study found Charleston’s trees can remove almost 600 million gallons during a particularly rainy day — there are important steps to take.
Cities and counties should consider tightening their existing tree protections or putting some in place if they don’t have them. Most larger governments protect grand trees: Those planning to remove such a tree often must get permission and, if granted, plant several smaller trees to offset the loss. But are those smaller trees sufficient, since one grand tree can wick up so much more water? It’s a question local leaders should ask.
Also, many ordinances don’t protect certain trees, including pines, which actually are among the best at wicking up groundwater and releasing it back into the atmosphere. Yes, even tighter tree regulations could increase housing costs, another major local challenge, but they also would work to make our cities more beautiful and sustainable — and dry.
But this work shouldn’t be left to government alone: The nonprofit sector could play an important role. While both the Charleston Parks Conservancy and the Coastal Conservation League advocate for tree planting and protection, it could be time for a new nonprofit group focused solely on trees — protecting existing ones and planting new ones.
There are interesting examples, including TreesCharlotte and the New York Restoration Project. Such groups could work with private property owners to plant and protect trees and could urge cities and counties to set goals for expanding their tree canopies, ensuring development doesn’t harm adjoining forests and protecting more open space.
Individuals, particularly homeowners, can do their part by planting and protecting their own trees that provide shade, cooling and drainage.
Sturdy live oaks, decorative palmettos, towering pines and many other species have long defined South Carolina’s coastal landscape. As we fight to preserve our low-lying communities from the threat of climate change, and struggle to maintain the Palmetto State’s natural beauty, we must plant, protect and cherish trees more than ever.