An elusive little stream creature is threatening again to force changes in a big Triangle highway project.
The dwarf wedge mussel, brown-shelled and thumb-sized, enjoys powerful legal protection because it is listed by the federal government as an endangered species.
Concern about its well-being is pushing the N.C. Turnpike Authority to choose between two routes for a planned extension through southern Wake County of the Triangle Expressway, a toll road now under construction in western Wake:
A corridor favored by the state and protected from development since the mid-1990s that runs south of Garner and Lake Benson, where it crosses Swift Creek and tributaries that are home to small numbers of dwarf wedge mussels. Known these days as the orange corridor, this path would affect only a few homes and businesses, and it has widespread political support.
A new corridor, floated as an option by the turnpike agency in September, that veers north of Lake Benson and rolls through the developed center of Garner. Town leaders say it would ruin parks and industrial centers, and it would bulldoze homes and yards in more than a dozen subdivisions.
The new option, known as the red route, is getting serious consideration because it has one advantage over the orange route: It crosses a section of Swift Creek where no dwarf wedge mussels have been found in the past.
Garner officials warn that the Triangle Expressway would cut their town in half, as a realignment of U.S. 70 did in the 1950s.
"And we've never recovered from that," said Hardin Watkins, the town manager. "Obviously this is an important road for the region, and we want to see that road happen. To us, the smart decision is to use the route everybody has been planning on for the last 15 or 20 years."
The dwarf wedge mussel has affected highway and other public works projects in several parts of the state since 1990, when it was added to the federal endangered species list.
Its presence in the Swift Creek watershed added years of delays and millions of dollars in costs to the U.S. 70 bypass of Clayton, four miles south of Garner, which finally opened for traffic in 2008.
Before the state could get permission to build the Clayton Bypass, Wake and Johnston county commissioners had to establish 100-foot stream buffers to prevent the runoff of chemical and sediment pollution that could smother the little mussel - and push it closer to extinction. Garner helped out, too, by adding stronger environmental safeguards to its development ordinance.
Now the Turnpike Authority has hired biologists to update recent environmental surveys of the Swift Creek watershed, to check up on the health of the dwarf wedge mussel.
An elusive quarry
A meandering stretch of Swift Creek in western Johnston County teems with freshwater mussels. Tim Savidge knows how to hunt them down and scoop them out.
Wading through the chilly water Thursday morning, Savidge peered through an orange, glass-bottom viewing bucket for faint signs on the shallow streambed: openings in the sand where buried mussels suck in muddy creek water and squirt it out again, clean.
Savidge, a biologist, ran his fingers across the sand to feel for the protruding tips of their shells. In 30 minutes, before his arm went numb, he plucked out of Swift Creek a few dozen dark-hued bivalves with colorful names: eastern elliptio, variable spike, creeper, Roanoke slabshell.
But not the one he was especially searching for, the dwarf wedge mussel.
Savidge works for the Catena Group, a Hillsborough environmental consulting firm. His work also will help gauge any environmental problems that might be tied to the new Dempsey Benton Water Treatment Plant on Swift Creek at Lake Benson.
It took 200 hours of stream survey work to find just seven dwarf wedges in 2007, Savidge said. Surveyors have found just five of them so far this year - including one found two days earlier, about 200 yards upstream from the spot Savidge and a co-worker, Ivy Kimbrough, scanned Thursday.
"We know they're still reproducing in here," Savidge said. "They're still in the creek in low numbers."
The United States has recorded about 300 species of freshwater mussels, he said.
"Probably around 70 percent of them have either gone extinct or are threatened or endangered. It's really a sign of how our society has treated the water. They need clean water, and they need stable habitat," Savidge said.
The threat of a turnpike splitting the town has become a unifying force in Garner.
"It's going right through my community," said Richard Corn, 77, who moved to Garner in March from Sarasota, Fla. Corn and his wife bought a home in the Village of Aversboro, a Garner retirement community.
"I can't afford, at my age, to have this impact taking place," Corn said. "It seems the Turnpike Authority has taken a cavalier attitude. They said they're going to let us know their decision in two years. That's not acceptable."
Town residents are lobbying the turnpike authority to quickly drop the red route from consideration, just as it eliminated unpopular routes through Holly Springs and Fuquay-Varina this month.
Turnpike officials are meeting with Garner neighborhood groups, and they have promised to attend a town-sponsored public information meeting Wednesday evening.
"We plan on being there, and we expect to hear a lot," said Steve DeWitt, chief engineer for the turnpike authority.
"We need the public to share the concerns they have. You can see what happened in Holly Springs, where the public outcry helped us pretty rapidly get those other things off the map.
"What's hindering the same thing here in Garner is that this dwarf wedge mussel is found south of Lake Benson, and not north of Lake Benson."
More studies have been ordered to check for the endangered mussel in the waters north of Lake Benson.
Gary W. Jordan, a U.S. Fish and Wildlife Service biologist working with the turnpike authority on the new TriEx project, said the agency was required by federal law to consider alternatives such as the red route through Garner.
But it doesn't appear to be a likely alternative to the orange route, he said.
"I fully expect that [red] alternative to be dropped by the Turnpike Authority once they document why they would not want to select that one," Jordan said. "I expect that alternative will have a whole lot more human impacts, and it would be extremely unlikely to be chosen."
DeWitt said he has heard plenty of objections from Mayor Ronnie Williams and other Garner officials, and he hopes to learn more about the town's concerns this week.
"We're being very careful looking at all the details, making sure the route we pick at the end is the best balance of all the issues we have here," DeWitt said.
He promised a resolution by 2012 but said the decision could come sooner, in the next few months.
email@example.com or 919-829-4527