A project to pave a portion of Old South Road in Aquinnah has pitted residents who feel the dirt road is an essential part of the rural character of the town, against others who say the paving is needed for environmental reasons to protect a nearby stream and pond.

Dukes County and the Wampanoag Tribe of Gay Head (Aquinnah) have applied for a variance to pave the historic byway to prevent further sediment runoff into the Occooch Stream and Pond.

The variance is required under a town bylaw that protects Old South Road, Old Lobsterville Road and Old Church Road as historic places and prohibits paving on them. Gravel, bluestone, crushed shells and wood chips are allowed for maintaining the roads, but asphalt is not.

A public hearing began before the zoning board of appeals last Tuesday and will continue tonight at 7 p.m. at the town hall.

The project is a joint effort involving the town, the tribe and the county. According to meeting minutes from the hearing last week, county manager Russell Smith said the county owns the road but has no money to maintain it.

Old South Road was a principal byway in the town; its name dates back to 1870. The east fork of the road is home to both tribal and nontribal families as well as the site of several affordable homes.

The project has two parts. The first would pave a portion of the road that slopes down toward the Occooch Stream and install a series of interconnected catch basins. A small leaching area at the end of the road would be installed to prevent overflow into a protected wetland. The paved area would be 10 feet wide, half the width of the existing road.

The second half the project calls for lining the road with vegetative swales on both sides to help stop runoff coming from Old South Road surrounding properties.

The project began the first week of June, when the swale and catch basins were installed, but construction stopped late last month when an abutter raised the possible bylaw violation with building inspector Jerry Wiener. Mr. Wiener advised town administrator Adam Wilson and Bret Stearns, project leader and director of natural resources for the tribe, that a variance was needed in order to proceed.

The plan to pave the road dates back to some 10 years ago. Mr. Stearns said at the time a tribal study of the pond showed that sediment runoff from the dirt road was affecting the ecosystem of the pond.

“The tribe looked at the biology of the stream and came to the determination that a great deal of the stream did not have the natural biotic community because it was smothered with sediment,” Mr. Stearns said yesterday. “We had a lot of evidence that the stream was getting choked out and the pond was getting too much sediment.”

In February 2005 the tribe wrote a grant application to the Environmental Protection Agency for a project to protect the stream at the base of Old South Road, just past the intersection of the road and Church street. Funding was approved in 2006, and in 2007 the tribe and county hired an engineer to survey the road. Meanwhile, the town created a trench on the side of the road to prevent flooding.

The town conservation commission and selectmen approved the project in 2009.

Yesterday Mr. Wilson said the town has stepped in at times to plow or regrade the road as a public safety measure.

Mr. Stearns said the project will cost $200,000; the lion’s share will come from the EPA grant and the remainder will come from tribal monies.

Alternatives to paving the road were examined, but because the road is primarily clay, there is little to no drainage, Mr. Stearns said. He said a combination of some paving with catch basins and swales of native plants is the best alternative.

A number of Old South Road residents attended the hearing last week to voice concerns and objections to the project.

Others support the project.

Mr. Stearns said no laws have been broken, and he is anxious to see the matter resolved.

“I was completely unaware that there was the need for a variance for this project because we had discussed it so long,” he said. “There has been zero paving of the road to this date and we’re following through with the correct process. We were simply unaware of the regulation.”

The zoning board of appeals asked Mr. Stearns for a management plan. The board is expected to review the plan tonight.