Dominion Power has proposed installing towers across the James River that would be visible from College Creek Beach on the Colonial Parkway. (Scott Neville/ For The Washington Post)

The federal government could decide this week if a 500,000-volt transmission line over the historic James River in Virginia, on towers almost 300 feet tall, is too great a development threat to the national parks in its path or a reasonable way for the local power company to serve its customers.

New Environmental Protection Agency rules are forcing Dominion Virginia Power to shutter its oldest and dirtiest coal-fired power plants, including two in Hampton Roads, in Virginia’s southeastern corner. The utility warns that the loss of power could lead to brownouts unless it builds a  7.4-mile power line that would span the same stretch of river that some of the first English settlers navigated in 1607 before landing at Jamestown.

But the project has drawn battle lines for two years between Dominion and national preservation groups, who say the power company’s plan would ruin the sight lines from some of the country’s most historically significant national parks.

The transmission line would cross the James on a series of as many as 17 towers — the largest being nearly as tall as the Statue of Liberty and, critics say, within sight of the tip of Jamestown Island, home to Historic Jamestowne, the historic Colonial Parkway and other historic resources.

The utility’s plans were approved by state regulators in 2013. The next step is a permit from the Army Corps of Engineers, which requires Dominion to seek permission to build towers on wetlands on the river bottom.

[Past coverage: Va. approves controversial Dominion power line over historic James River]

The Corps’ review now covers the project’s potential impact on roads and bridges in the area. How deeply it considers the potential damage to wetlands, fish and the parks’ viewshed is more murky, and the core of the tension between Dominion and the power line’s opponents.

“We’re talking about Historic Jamestowne here,” said Theresa Pierno, chief operating officer for the National Parks Conservation Association, which has forwarded 40,000 signatures to the Army Corps in opposition to the project.

“It’s a national treasure,” Pierno said. “It’s been pretty much untouched from the water.  You don’t put up 17 towers as tall as the Statue of Liberty and not have an impact.”

The parks association fears that the Corps does not plan to conduct a more stringent environmental impact study than the assessment it’s doing now. The group has pressed Dominion to come with alternatives that are less disruptive to the environment, include putting the lines underwater, doing nothing or putting them in another location.

But Dominion says it has considered alternatives. “None of them met the standards of what we need to do in the time frame we have to build the project,” company spokeswoman Bonita Billingsley Harris said.

[New Va. law shields Dominion Power from financial reviews]

The EPA is requiring the old coal plants to shut by 2015; Dominion is seeking a year’s extension on the deadline.

“In a nutshell, it was clear that the [current] route has the least impact that can be done in time,” Harris said.

Both sides expect a decision this week or soon after because of an upcoming change in leadership in the Corps’ Virginia region.

Army Corps spokesman Patrick Bloodgood said Tuesday that the agency is “still going through the environmental assessment process” and is “not leaning one way or another in a decision.”  If the government concludes that the project “will result in significant impact to the environment,” a more rigorous environmental review would be required, he said.

“Due to the complex nature and many variables involved, we cannot put a date on a calendar of when we expect a decision to be made.”