Facing final approval from the Westbrook Planning Board next week, the Dirigo Plaza shopping center is poised to become the newest retail hub in Greater Portland.

If approved, construction could start by Thanksgiving.

The nearly 500,000-square-foot commercial development destined for the former Pike Industries quarry has been a few years in the making, and will mark a significant transformation to a large portion of the city’s gateway between the Westbrook Arterial and Main Street stemming from Portland.

Among the major changes to the landscape, which has been a working gravel pit since the 1940s, is extensive traffic improvements to nearby aging intersections.

The Westbrook Planning Board will host a public hearing and vote on the final site plan approval on Tuesday, Oct. 18, at 7 p.m. in Room 114 of Westbrook High School.

The developers, J&J Gove Development, announced earlier this year that Walmart would be one of the project’s anchor tenants – a decision that has been met with some criticism from residents – but the team has not announced any other tenants since. A distinctive feature of the development is a pond created from the former Pike gravel pit.

Jeffrey Gove said last week that he had planned on final approval coming sooner, but that he delayed in order to receive the project’s permit from the Maine Department of Environmental Protection prior to coming back to the Planning Board.

City Administrator Jerre Bryant told the American Journal last week that the developers are shelling out some $6 million for the traffic and intersection upgrades, with a focus on making them more pedestrian-friendly.

Gove said the traffic mitigation plan was agreed to by the Maine Department of Transportation, as well as by officials in Portland and Westbrook. He said his team will split up in order to get final approval from both cities on Oct. 18.

Due to its proximity to Portland, many of the traffic improvements will take place along the city line, including where Main Street turns into Brighton Avenue at Riverside Street, and at exits 47 and 48 of the Maine Turnpike.

“The offsite mitigation just in Portland is going to total about $2.3 million,” Gove said.

In Westbrook, which will receive some $1.2 million in traffic upgrades, focal points are the intersections of Main Street and Larrabee Road and a new intersection at what will be a main entrance to Dirigo Plaza across from the Westbrook Crossing shopping center. Gove said there are another $3 million in site access upgrades.

At a Planning Board public hearing in July, most of the concern from residents was focused on traffic. A traffic engineer working for Gove has predicted more than 13,300 new trips to the site on an average weekday, and 18,800 on a peak Saturday.

If approved next week, Gove said he would most likely close on the property by Thanksgiving. His team has a purchase and sale agreement with Pike Industries that is contigent on receiving the necessary approvals. He said construction would start immediately.

The largest portion of construction, known as the north campus, would take place through next year, Gove said. That portion includes the shops and entrance from Main Street, with a bus drop-off and kiosk.

“I think we’d get some tenants open next fall,” he said, but added the majority would probably be opening in 2018.

Construction on the south campus, stemming from the arterial, would follow. He said his team is still “feverishly” working with prospective tenants for the south campus.

Throughout the long process toward approval, reaction from members of the Planning Board has been largely positive. Many have pushed for the pedestrian-friendly elements and focus on the future pond.

Once the pond is filled, which will take a matter of a few years, a walking trail around its perimeter will open. The parcel is mostly in Westbrook, but also crosses into a small section of Portland.

There are some, however, who don’t want to wait for the pit to fill completely. Gove said he was on site two weeks ago and saw a few people kayaking in the water.

The former Pike Industries gravel pit between Main Street and Larrabee Road is already filling with water, as developers await final approval Tuesday to turn the surrounding parcel into a large retail center. The pit is designed to become a focal point of the development, eventually becoming a lake once it fills completely.