MECHANICSVILLE, VA. -- A Hanover County landowner has bulldozed about half of a series of well-preserved Civil War earthworks on his property, angering some county officials and historic preservationists.

"I'm doing what I think is right," Oscar Via Sr. said this week.

Via hired a crew to begin bulldozing the 1,000-foot long trenches last Saturday.

The earthworks are on 322 acres Via owns south of U.S. 360 and west of Route 615. He has an option to sell the tract to PMG One Partnership in Mechanicsville, which plans to develop it into a $132 million residential and commercial development.

The trenches are believed to have been built in late May 1864 by Union infantry, according to Robert B. Giles, vice president of the William Byrd branch of the Association for the Preservation of Virginia Antiquities.

"This is something you can't simply replace," Giles said. "The owner has hurt everyone and future generations. It was a self-inflicted vandalism."

Giles said the earthworks are significant because they are in a higher state of preservation than most Civil War trenches, including those at the nearby Cold Harbor National Battlefield Park.

"These trenches were or are in a pristine condition," Giles said. "It was a very valuable historic resource."

The trenches were brought to the county's and the developer's attention by Giles and his organization a few months ago.

Preserving the earthworks was the center of debate when the County Planning Commission heard a rezoning request earlier this month.

As part of its recommendation for approval of the development, the commission wanted 95 percent of the trenches on the site to be preserved and protected with a 100-foot buffer zone.

The board meets next week to consider the rezoning.

As late as last week, developers were working on plans to save more than the 10 percent they had originally offered to preserve, said John V. Cogbill III, a Richmond lawyer representing the partnership.

Because plans call for an office park to be situated on and around the trenches, Cogbill said it would have been easier to preserve the bulk of the earthworks. One of the general partners even said the partnership wanted to save all of the trenches if it could.

"I was absolutely dismayed," said Cogbill, who toured the site for the first time Sunday.

Several county officials said Via indicated to them that he decided to bulldoze the trenches because they had become an impediment to the project's approval.

But Supervisor C.E. Davis said the bulldozing "severely jeopardizes" his support for the project.