A state plan to protect the Carolina heelsplitter, an endangered mussel found in Mecklenburg and Union counties, could roll back a key safeguard.

The proposal is aimed at mussel habitat in the Goose Creek watershed, it includes two options. The state Environmental Management Commission will choose one this year.

One version preserves the 200-foot buffer zones now in place along year-round streams in the watershed. The other allows buffers as narrow as 50 feet wide, and more permitted uses within them, but it bans construction in floodplains and requires compensation when buffers are damaged.

State and federal wildlife biologists have argued that 200-foot buffers, left in their natural state, would give the heelsplitter the most protection. The mussel can't survive water pollution that buffer zones intercept.

A 2005 survey found only six heelsplitters in Goose Creek and five in a tributary, Duck Creek. Federal biologists say continued development could wipe out both creeks within a few years.

But wider buffers, which extend on both sides of streams, also leaves less land available for development in the watershed. Mint Hill, in the headwaters of Goose Creek, has long chafed over those restrictions.

"Obviously, on the surface of it, we favor the option that's got the 50-foot buffers," said Town Manager Brian Welch. "One of my biggest concerns is protecting our citizens' property rights."

Following the ruling of an administrative law judge, the towns of Mint Hill, Indian Trail and Stallings last year adopted 200-foot buffers along year-round streams in the Goose Creek watershed.

That standard was to remain in place only until a plan to specifically protect the mussel -- the one recently proposed -- was adopted.

State officials will hold a May 22 public hearing in Charlotte on the new proposal and take comment on it through June 30.

The N.C. Wildlife Resources Commission, which was among state and federal agencies that help protect the mussel, still favors the wider, undisturbed buffers it recommended in 2002.

"I think it's safe to say that we fought pretty hard to preserve" 200-foot buffers on year-round streams and 100 feet wide on seasonal streams, said the commission's Scott Van Horn, who oversees aquatic non-game animals.

The N.C. Wildlife Federation, which with the Sierra Club filed the legal challenge that led to the judge's ruling, said both options will help protect the heelsplitter.

"The Wildlife Federation supports undisturbed buffers and we're pleased that this proposal includes that," deputy director Tim Gestwicki said.

Both versions of the proposal require builders to control stormwater from building sites of a half-acre or more. They ban new or expanded discharges from sewage plants in the watershed, and require measures to reduce ammonia, which can be toxic to aquatic life.

The plan also allows for exemptions from preserving buffers, such as when doing so would make land unusable.

Adoption of the plan won't settle controversy over the mussel. Charlotte-Mecklenburg Utilities is beginning an environmental study that could lead the state to lift a moratorium on extending water lines into the Goose Creek watershed.

The protection plan now under review, Welch said, "will provide me with some ammunition: 'We've done what you've told us to do to protect the species. Now give us some water.' "

Get $150+ in coupons in every Sunday N&O. Click here for convenient home delivery.