A leading contender for a regional jail site would fuel urban sprawl, degrade the Roanoke River and make flooding worse in Salem and Roanoke, according to the local branch of the Sierra Club.

The executive committee of the club's Roanoke River branch voted Monday to oppose the Higginbotham Farms site, a 54-acre tract off West River Road near Dixie Caverns. Bounded on two sides by the Roanoke River, nearly 25 percent of the site is in a flood plain.

Executive committee member Mark McClain said Tuesday that the group felt obligated to speak because, "No one has really talked much about the effect this might have on a site with some environmental sensitivity."

The Sierra Club's press release also pointed out that the site is not adequately served by utilities or roads. In the release and in a telephone interview, McClain referred to the idea of building a jail in what is now a cow pasture as "leapfrog development."

"That part of the county is not exactly rural," McClain said, "but it's not the built-up city, either."

Representatives of the administrations and sheriff's departments of Salem and the counties of Roanoke, Franklin and Montgomery have been discussing regional jail plans for nearly 10 months. The group rated the Higginbotham Farms property first among 18 sites. A citizens advisory group appointed by the Roanoke County Board of Supervisors rated the site among its top choices.

"It's probably one of the better sites available to us," said Assistant County Administrator John Chambliss, who has headed the project for Roanoke County.

Chambliss said that the jail would likely be built on the portion of the property that's out of the flood plain. But Chambliss said he realizes that there are challenges involved in building on the site.

The objection about leapfrog development could apply to almost any site that's been considered for the jail, Chambliss said, citing the difficulty of finding 30 acres in the Roanoke Valley that's not in some housing development's back yard. Building in more developed areas would mean building a multistory jail, something Chambliss said would add cost and operational challenges.

Bob Flynn, a spokesman for the Roanoke Regional Home Builders Association, cited the county's frequent talk of smart growth and wondered if the county had followed its own directives in this case.

"I wonder if Roanoke County has looked at its inventory of infill properties," Flynn said. "Of course, that would be politically tough. But that is part of smart growth."

Smart growth advocates concentrating development where roads, utilities and other infrastructure already are there to support it.

Developing in a flood plain brings added responsibility, Flynn said. Some projects can improve conditions downstream, he said, but flood plain development also can make things worse downstream.

"We feel that the need for development must be tempered with the imperative to protect our environment," McClain said in the Sierra Club's press release. "We strongly believe that Roanoke County can and should find a site for the new jail that does not contribute to the leapfrog urban sprawl across the region nor to the further degradation of the river whose valley we have borrowed for our home."

The Roanoke County Board of Supervisors is scheduled to consider potential jail sites at its Jan. 11 meeting.