HAMPTON — Terry and Lisa O'Brien originally planned to renovate their Portsmouth Avenue property overlooking the Hampton Harbor and rent it out. The view of the bustling harbor and the bridge that spans its mouth convinced them to make it their home.

Now, the O'Briens, who invested more than $1 million into their property since buying it in 2015, are concerned the state's need to replace the Neil R. Underwood Memorial Bridge in four years will force them to leave their home behind.

State officials say their land and five other properties could be taken by eminent domain if a new bridge is built on the east side of the current bridge.

"Who would want to leave?" said Terry O'Brien, 55. "It's beautiful. It's a great spot."

The six homes sit lined up along Portsmouth Avenue on the Seabrook side of the bridge, the state's No. 1 red-listed bridge set to be either replaced or rehabilitated in 2023. Four of the homes including the O'Briens' are technically in Hampton, while the other two are just over the Seabrook line.

State officials say the location, size and type of bridge being built will be determined later this year. Building on the west side would allow the properties to be left alone, according to Jennifer Reczek, a project manager at the state Department of Transportation, and stakeholders say there is strong support for that alternative. She said DOT will have to work with environmental officials to consider the impact of that alternative on endangered species living there, though, as well as work with the Army Corps of Engineers which has jurisdiction there.

While DOT says taking property by eminent domain has not been deemed necessary yet, local officials are concerned it is a real possibility. Hampton selectmen on Monday told Town Manager Fred Welch to advocate for alternatives that would avoid taking residents' homes. Welch is part of a project advisory committee working with state officials on future plans. The group includes residents and members of the harbor's business community and is holding another public meeting Jan. 30 at the Seabrook Community Center.

Welch said a bridge could be built to the east of the current span without taking the six homes, but he said officials believe expensive retaining walls would be needed to support the bridge to allow the homes to stay in place. He said the bridge could also be replaced "in kind" to match the current structure's design and placement.

"Short of that, these properties are going to be taken by forced eminent domain, and the people are going to have to relocate," Welch said.

Selectman Rick Griffin said Thursday it would be "ridiculous" if residents were forced to move because their properties were taken, but he also said losing the tax revenue from those high-value properties would hurt the town financially. Town officials have said Hampton is already strapped in funding services at the beach like police and fire. Public works officials have also said much of the town's infrastructure will need to be replaced in the coming years.

"I don't want to see the town's tax revenue taken away," said Griffin. "We need all the tax revenue we can get, and we need to look at this as a broader picture."

Some advisory committee members say they believe no properties will need to be taken by eminent domain. Hampton Beach Village District Chairman Chuck Rage, also part of the advisory committee, said the topic of eminent domain comes up at each meeting but said stakeholders are universally hopeful for a bridge to the west. He also said it would not be practical for the state to choose a bridge to the east because it would cost so much more to purchase those six expensive properties.

"It just doesn't make sense (to go to the east), and then the cost would be higher and we all know that we don't have a lot of money in the state," said Rage. "I think everybody at the table was steering towards the west side."

The project is expected to cost $28 million based on preliminary estimates. DOT bridge engineer Jim Murphy said at a September meeting the bridge has “significant issues,” from cracked and eroded piers to rusted bearings that may cause locking. The bridge’s lift mechanism has failed twice since summer 2017, stuck in the down position for two days that July and in the up position for more than an hour in May 2018.

If eminent domain is necessary, Reczek said DOT starts the process by reaching out to homeowners and offering to negotiate. If that fails, she said the state resorts to taking the property by eminent domain through the courts.

If the presence of endangered species rules out a bridge to the west, Lisa O'Brien joked she's "happy to take them over here" on her and her husband's side of the bridge if they need a home.

She and her husband say they accept the reality that the state could take their home. They said even if the state pays them a good value for the property, their personal investment over the last three years would make the process difficult.

Lisa O'Brien, 52, an interior designer, organized the home and said she would miss her custom kitchen, which is connected to a living area that overlooks the harbor through large windows. The O'Briens had also installed hurricane shutters on their deck to prepare them for the years ahead of living on the beach.

"I don't think we have much recourse," she said. "It is what it is."