By a near 6-1 margin, voters approved a referendum to create a sewer district for the Mastic-Shirley area, paving the way for what officials say will bring major economic development and environmental improvements to the region.

The final vote was 414-71.

“Voters resoundingly approved the sewer district and made an investment in their environment, their community and themselves,” said Councilman Dan Panico.

The vote, which includes phases 1 and 2 of a potentially much bigger area, affects close to 1,900 homes and about 150 commercial properties, located mainly along the Montauk Highway business corridor between the Forge River and just west of the William Floyd Parkway.

A sewage treatment plant will be built at Brookhaven Calabro Airport.

Peter Rodriguez and his wife, Grace, voted in favor of the project.

“This is to bring us up to par in terms of infrastructure and improving our waterways,” Peter said.

William Hilton and his wife, Maria Giustizia-Hilton, also voted yes.

William is a trustee for the Village of Patchogue and Maria is its director of parks and recreation.

“What the sewers did for Patchogue was just unbelievable” in terms of economic development, William said. And with their house sitting right off the Forge River, the couple said they look forward to taking advantage of the recreational opportunities offered by revitalized water.

If the vote did not go through, the region would have lost $168 million in one-time FEMA funding. There will be no cost to either residential or commercial property owners for construction of sewer lines, the sewer treatment plant and other sewer system infrastructure.

Homeowners will pay $470 in annual maintenance costs. Commercial properties will be responsible for one-time costs associated with hooking up to the sewer system. However, there is aid available to help with those costs.

With the sewer district now approved, the next step is to push for phases 3 and 4, which encompass a larger area south to the tip of the peninsula. About $500 million in funding has already been requested for that effort.

After the vote, Suffolk Legis. Rudy Sunderman expressed relief and joy.

“This is very exciting times for the Mastic-Shirley community.”