Johns Island Drainage (copy)

A grand tree on Johns Island preserved in a well, which could risk the long-term health of the tree. 

There’s nothing particularly unusual about a request to cut down 22 grand trees on Johns Island. But that “normalcy” is the rub, and it offers a window into what’s wrong with the way the island is being developed.

Charleston’s Board of Zoning Appeals will consider a variance Wednesday for a developer to knock down those trees on a densely wooded 61-acre parcel that’s part of a housing project off Cane Slash Road. Some of the trees are in the way of planned roads or homes. Others are in poor condition. The developer plans to “save” at least 103 trees.

What many developers do — remove most of the trees and use sandy clay from retention ponds to build up home sites to the base flood elevation — meets city requirements. But it fails to recognize the flood-sensitive topography or the cumulative effects of development on drainage.

The popular formula is designed for Anytown, USA. And it’s become clear that it’s unsustainable on Johns Island.

That’s partly why three frustrated activists recently wrote to state and federal authorities, urging them to investigate whether the city was failing to protect residents from known flood risks. They also urged officials with the National Flood Insurance Program to review Charleston’s flood-risk rating or to suspend the city from the program altogether.

Meanwhile, the city hired its first floodplain manager this year and is working toward rewriting stormwater regulations. But getting ahead of the curve — thousands of homes have already been permitted on Johns Island — is the real challenge.

The second phase of the Twin Lakes development, where the tree-removal request is pending, was permitted three years ago. Crescent Homes, the developer, already had to reconfigure its plans because some of the marsh setback lines changed in the interim, and that altered its request. Development executive Bob Pickard said he was working with city officials to save as many trees as practical. The request was reduced from 39 to 22 trees, and 195 new ones would be planted. Mr. Pickard should be commended for trying to limit the damage to trees on the property. It’s unrealistic to think that houses can be built without removing some of them. But the region’s explosive growth means government officials must be vigilant in protecting as many of these Lowcountry-defining resources as possible.

Part of the sustainability problem, according to Jason Crowley of the Coastal Conservation League, is that housing developments typically leave about 80 percent of the land impervious, increasing runoff. And most of the city’s ordinances related to development in floodplains were written before the current style of development emerged. The existing rules, he said, don’t respect the unique topography defined by dunes and swales that funnel runoff into streams and the Stono River.

City Council rejected a six-month moratorium on Johns Island development earlier this year. And it’s not clear that having one in place now would help. So far, city officials have been reluctant to use their rezoning powers to limit housing on vacant land.

Enacting new runoff regulations as soon as possible should help address some of the flooding concerns, but city officials also need to rethink the overall approach to building on the island. And developers need to come up with better ways to make their projects fit the environment.