WILLIAMSBURG — There was a catch to the public forum this week about whether Dominion Energy should be allowed to build a power line across the James River near historic Jamestown:

The power line is already built.

So while the Army Corps of Engineers painstakingly gathers public comment and studies aspects of the “proposed” project to see if it merits a permit, the 500,000-volt lines have already been strung across the James. Atop 17 new towers, some of them 300 feet high. Since February.

“To my knowledge, we have not had an instance like this,” said William “Tom” Walker, regulatory chief of the Army Corps’ regional office in Norfolk.

Opponents want authorities to order Dominion to tear down the towers. The utility argues that doing so would be disastrous for the power grid. It’s a fittingly strange final chapter for a project that has stirred strong feelings for years.

Local residents have long argued that the crossing — within view of part of Jamestown Island — would spoil one of the holy sites of American history, a section of river largely unmarked by industry since Capt. John Smith helped start the nation here in 1607.

Later this month, in fact, dignitaries will converge on Jamestown to celebrate the 400th anniversary of the first session of the House of Burgesses: the birth of representative democracy in the New World. The ghostly towers are visible from the eastern tip of the island, as well as from the Colonial Parkway leading up to it and from nearby Carters Grove Plantation, a historic landmark.

“There’s been so much work to preserve this part of the river, and this project violates what those efforts are all about,” said Jamie Brunkow of the James River Association, which has fought the project.

The Army Corps awarded Dominion a permit for the project in 2017, but opponents immediately challenged it in court. While hearings and appeals played out, Dominion built the power line, saying it was too crucial to delay.

Earlier this year, though, the U.S. Court of Appeals for the D.C. Circuit ruled that the Corps had not fully vetted the proposal. The court vacated the permit and ordered the Corps to complete an environmental-impact statement. When Dominion and the Corps asked the court to reconsider, arguing that it was, um, a little late for that, a panel of federal judges reacted harshly.

“Neither petitioner bothered to advise us that construction on the project had been completed and the transmission lines electrified the week before we issued our opinion,” the panel of Chief Judge Merrick Garland and Judges David Tatel and Patricia Millett wrote.

Further, the judges pointed out that Dominion had assured a lower court that if the permit was ultimately revoked, the company would simply dismantle the towers. Now it was arguing that such a move would cause “disruption.”

“We find the foregoing more than a little troubling,” the judges wrote. “Had the Corps and Dominion said all along what they say now,” the court would have considered preventing construction in the first place, they wrote. The utility was trying “to place an even heavier thumb on the scale” by arguing that it had spent $400 million, when the project was earlier represented to cost $178.7 million, the judges said.

They sent the matter back to federal district court for an ultimate ruling.

In the meantime, the Corps is preparing the environmental-impact statement, due late this year.

“We knew the risk,” said Kevin Curtis, Dominion’s vice president for electric transmission. “Hindsight is 20-20 . . . but I wouldn’t hesitate to do it again.”

In an interview at Dominion’s highly secured transmission control center outside Richmond, Curtis gestured at a wall bearing a live map of the state’s power grid. Created from 90 separate display screens, each one measuring 70 inches diagonally, the wall loomed over a darkened chamber lined with computers like something from NASA’s mission control.

“I appreciate the passion behind all the folks that have discomfort with the line,” Curtis said. “But at the same time, this is what’s in the back of my mind — this place, this grid.”

Up on the wall — on what looked like a giant, multicolored wiring diagram of the entire state — a green line represented the James River crossing. It connected the Surry nuclear power plant on the southern side of the James to the Skiffes Creek power station on the north. It is the only 500,000-volt line serving the Peninsula — that narrow neck of Virginia from Williamsburg down to Hampton and Newport News that’s home to a half-dozen national security installations.

Recently, two coal-powered generating plants in Yorktown were decommissioned because they were old and inefficient. Without those, Curtis said, the region did not have the infrastructure to withstand the demands of continued growth, or hurricanes, or long, hot summers.

Based on extensive computer simulations, he said, the peninsula would be vulnerable to rolling blackouts or worse. In an emergency situation, that instability could cascade outward and affect the rest of the state, he said.

Dominion took extraordinary steps to soften the project’s impact on the historic landscape, he said, siting the line and building the towers in a way that minimizes their appearance from Jamestown Island.

Walker, of the Army Corps, said in a separate interview that he was confident in the initial decision to award the permit.

Engineers first did an environmental assessment to see if there were any major issues that warranted conducting a more in-depth impact statement, he said. “We found no significant impact.”

That review included looking at impact not only on the environment but also on cultural and historical aspects of the zone around that part of the river. The Corps logged nearly 40,000 comments from members of the public, he said. The new impact report should be available for public comment by November, the organization said.

At the public forum held by the Corps on Wednesday night at a hotel in Williamsburg, artist renderings of the project stood side by side with photos of the real thing. Scores of people showed up, many of them longtime opponents. One group had gone out in boats the day before for an up-close look at the transmission line.

“It’s awful. It’s hideous,” said Margaret Fowler, who whipped out an iPad to show photographs of the concrete and metal towers rising from the brown river water.

Fowler, 68, is a retired financial executive who helped found the Save the James group in 2012. Like many of the other opponents, she lives in an affluent development in sight of the river — and the towers — drawn by the area’s unique history.

“This is America’s birthplace,” she said.

There is other development along this stretch of the James. The twin domes of Dominion’s Surry nuclear plant are visible across and downriver from Jamestown. Houses and roads dot parts of the shoreline.

But there are some areas — particularly along the marshy southeastern edge of Jamestown Island, where tall pines come down to the water’s edge — that suggest the wilderness where Powhatan Indians once encountered the first English settlers.

“It’s easy to lose yourself out there,” said Brunkow, who as riverkeeper spends as much time as he can on the water. “It’s so calm, and the river is very wide. . . . So to come around the bend from Hog Island and see this intrusion that’s really industrial in nature is very jarring. You can hear the crackling sounds of the lines themselves.”

Opponents argued that Dominion had viable alternatives, such as a right of way that it already owns down the middle of the peninsula or even burying the lines under the river. Building the crossing, even in the face of court challenges, “is just really the height of arrogance,” said Glen Besa, 68, of Richmond, who retired in 2016 as Virginia director of the Sierra Club.

Dominion has faced similar criticism in recent years for other projects, most notably its efforts to build the Atlantic Coast natural gas pipeline across the western and southern parts of the state. There, too, federal judges have halted work and chastised federal agencies for taking shortcuts in approving work permits.

One such problem — in which federal judges ruled that Dominion does not have proper permission to cross the Appalachian Trail — has left the pipeline mired in delays. There, too, the utility had moved ahead without a ready alternative.

Even though the James River power lines have been built, opponents view the court’s ruling as an 11th-hour victory. “Dominion said, if it goes against them, they can always tear it down,” Fowler said. “Well, it’s gone against them, and here we are, and they can take it down.”

If it’s expensive and a lot of trouble, too bad, said Joy Oakes, regional director of the National Parks Conservation Association, which brought the court challenge against Dominion and the Corps. “This is about a place that belongs to everybody. It’s not about one utility’s corporate goals,” she said.

Curtis, the Dominion executive, said he understands the importance of the historic site, but he said his job is to make sure the people who live there today and into the future have reliable access to electricity.

“It’s easier to armchair quarterback when you’re not responsible for the outcome,” he said. If the permit isn’t reinstated later this year, he said, “if for some reason it doesn’t go our way . . . that’s an issue that has significant consequences.”