The best way to keep a home from flooding is to build it outside of a floodplain. That’s not always an option in Charleston, however, where about 60 percent of the city lies at low enough elevation and close enough to water sources that the Federal Emergency Management Agency requires flood insurance for homeowners.
So the next best option is to build homes in a way that at least makes them less susceptible to flooding, which generally means building them higher off the ground.
There are two ways to do that: Raise the ground beneath the house or raise the house itself. The first method has the downsides of changing the way water flows on the surrounding property and possibly exacerbating existing drainage issues. So the second is obviously ideal.
To that end, Charleston officials are considering raising the minimum freeboard — the height of a home above the FEMA-designated flood line — to 2 feet from the current minimum of 1 foot.
Not only would that be a sensible change in terms of protecting new homes from stronger storms and higher seas in the future, but it would benefit existing homeowners as well by helping lower flood insurance rates citywide.
Other recent progress has involved updated building rules in particularly at-risk areas like the Church Creek basin in West Ashley, and work on a broader overhaul of the city’s stormwater management guidelines, among other efforts.
Building homes higher off the ground raises the cost of construction, of course. And that’s something worth taking into account in a region where housing is too often unaffordable for the average worker. But repairing flood damage is also catastrophically expensive.
Unfortunately, some mistakes have been made in Charleston over the past few decades. And homeowners unwittingly stuck on vulnerable properties need help.
The city has more than 670 so-called repetitive loss properties, nearly a quarter of all such properties in South Carolina, which have flooded multiple times causing significant structural damage.
That’s partly because city officials for years took a troublingly lax approach to preventing problem flooding, including most egregiously in granting a variance in the 1980s for homes on James Island built below the flood line.
Righting those wrongs will mean buying out properties that have flooded on several occasions, tearing down homes and, ideally, creating green space or other features to help draw water away from surrounding neighborhoods.
A few dozen homes in West Ashley are already slated for buyouts in a partnership between FEMA and the city. Many more are still in need.
Charleston’s floodplain manager expects the list of repetitive loss properties to be fully updated — meaning it will include recent major flood events like Tropical Storm Irma and Hurricane Matthew — by the middle of this month. That will offer a better idea of the scope of the problem.
Solving flooding in a low-lying coastal city is a complex, multifaceted effort. But two of the most straightforward fixes are ending the headaches and heartaches for homeowners in repetitive loss properties and making sure new homes don’t flood or cause issues elsewhere.
It’s far better to prevent problems and resolve existing ones than to have to make costly repairs again and again.