An artist rendering of the Blue River Estates project.

An artist rendering of the Blue River Estates project. Credit: Handout

Even as construction of a new apartment building snarls traffic at the intersection of Peconic Avenue and East Main Street in downtown Riverhead, a site plan for a second big residential project across the street has been filed with the town.

Summerwind, the 52-apartment building under construction and slated to open later this year, includes restaurant and commercial space and workforce housing. The 48 condo units in the proposed Blue River Estates will be set at market prices.

But the two projects have at least two things in common: They will bring hundreds of people onto Main Street, and they already are changing the image of the town.

While some older buildings are being renovated to include some apartments, Blue River Estates will be the first new all-residential structure on Main Street in decades.

"It could be the first one ever," Town Supervisor Sean Walter said.

The five-story project at 11 W. Main St. has 48 ground-floor parking spaces. Part of the building would rest on pillars; the ground in the rear slopes down toward the Peconic River.

The planning and review process could take from six months to more than a year, town officials say.

Blue River Estates requires the demolition of a three-story building now housing the Long Island Science Center, whose interactive programs and exhibits are designed for elementary-school-age students. School tours of 50 to 100 children visit daily during the school year.

Executive director Michelle Pelletier said the museum hopes to move to another, larger building downtown, adding it is too early to know when it would have to close down.

Riverhead Town councilwoman Jodi Giglio, an investor in Summerwind, said the apartments from the two projects will help meet pent-up demand for new housing in town, and noted Riverhead's downtown zoning allows a total of 500 new housing units. "We have a lot of people who say they want to live here, but can't afford the taxes on a big house," she said.

Summerwind is workforce housing, with rent on a sliding scale for people who earn up to 80 percent of Suffolk County's median income. Condo prices at Blue River -- units range from 858 square feet for a one-bedroom unit to 1,304 for a two-bedroom unit -- have not been set, according to the site plan filed with the town.

"To have a sense of home ownership down there and to add people who are connected with the landscape, it's just phenomenal for the downtown area," Walter said.

He cautioned that building all 500 housing units could overtax the town's ability to treat sewage.

Bill Allan, who runs the Minuteman Press store across the street from the proposed Blue River complex, said projects in downtown Riverhead tend to be studied for years before anything happens. On his wall, he has a poster for the grand opening of the Suffolk Theater -- scheduled to open next month -- which he printed five years ago.

"Believe me, I'd love to see it go up," Allan said of Blue River. "If you bring in people to live downtown, it will be revitalized."