In the past few years, major flooding has made big news. Houston’s disastrous inundation during Hurricane Andrew stands out, but other communities have also been hit: Charleston flooded during Hurricane Irma last year, and central Louisiana saw historic floods caused by heavy rains in the summer of 2016.
In the aftermath of these events, there’s new scrutiny on development and building practices in low-lying areas. One practice being looked at is the use of fill to elevate land above the local flood elevation.
There’s controversy in Houston about filling land to get it out of the floodplain, the Houston Chronicle reported on April 7
(see: “Development tactic questioned in post-Harvey era,” by Mike Snyder and Nancy Sarnoff). “While the use of fill for this purpose is not uncommon in the Houston area,” the paper reported, “some experts say it’s questionable — particularly at a time when long-held assumptions about flood resilience are being re-examined in the aftermath of Hurricane Harvey.”
“The big problem in the Houston area is, you start using fill, you can fill so much that there’s no storage left,” Larry Larson, director emeritus of the Association of State Floodplain Managers, told the Chronicle.
From the report: “Harris County requires developers to offset fill by creating an equivalent amount of water storage, typically through on-site detention. Such rules reduce adverse impacts but don’t eliminate them, Larson said.”
They don’t call Charleston, South Carolina, and vicinity “the Low Country” for nothing — and in that market, much of the remaining buildable land is in areas at high risk of flood. According to a report in the Post and Courier, development in those areas is putting new homes at risk, and also increasing the risk to existing homes (see: “Another man-made flooding fiasco in the making on Johns Island,” by Abigail Darlington).
“Developers are using building methods that disrupt the land’s natural capacity to absorb water, causing a compounding problem as more subdivisions multiply without a coordinated drainage plan in the fastest-growing part of the city,” the paper reported. “Recently developed areas along River Road, as well as Maybank Highway near the Trophy Lakes community, already are flooding. City officials say they’re studying how developments shift drainage patterns in the overall watershed, and that could lead to stricter stormwater regulations for the island’s future developments.”
Kinsey Holton, Charleston’s stormwater program manager, told the paper that the city doesn’t regulate how developers use fill material to elevate their land: “It does allow one property owner to fend water off onto another property owner, and it’s a really complicated issue that a lot of municipalities are dealing with,” he said.
And development of low-lying land continues despite pushback from existing homeowners concerned about flood risk, the Post and Courier reported (see: “Charleston OKs another big development in a Johns Island floodplain,” by Abigail Darlington).
