The city is moving forward with a plan to consolidate two hospitals on Roosevelt Island, which could free up a large parcel of land south of the Queensboro Bridge for residential development, local officials said.

The dilapidated Goldwater Hospital campus of Coler-Goldwater Specialty Hospital, whose footprint by some estimates covers a full 10 acres, is more than half a century old. The 995-bed facility needs to be modernized, and its services could be moved to an expanded Coler Hospital campus on the north side of the island, under a plan presented last week to hospital officials. Moving Goldwater Hospital would create one of the last large undeveloped city-owned land parcels, local leaders said.

The consolidation plan is riling island residents and their elected officials, who say their overburdened transportation infrastructure could not handle an influx of new residents if housing were erected on the site.

“Given the high cost of real estate in New York these days, it seems inevitable that it’s going to be expensive housing,” the president of the Roosevelt Island Residents Association, Matthew Katz, added. “I’m very concerned,” Council Member Jessica Lappin, a Democrat who represents Roosevelt Island, said. “This was supposed to be a planned community. I’m concerned about the infrastructure for the people there already — forget about adding even more.” The City Council could vote against any residential development plans for the island.

Officials at the city’s Health and Hospitals Corporation say it is too early to formulate definite plans for the future of the Goldwater land parcel.

No matter what is done with the site, Roosevelt Island, most of which is owned by the state under a 99-year lease that expires in 2068, is undergoing a dramatic redevelopment, with nine residential high-rises in different phases of completion.

Three of the buildings, which rise as high as 24 stories and whose units are selling at market rates, are already fully occupied; two buildings broke ground last month. The island has become a popular residence among United Nations diplomats because of its proximity to the U.N. headquarters on Manhattan’s East Side.

The president of the Roosevelt Island Operating Corporation, Stephen Shane, said the biggest obstacle to development on the island is its transportation infrastructure. The only ways to Manhattan from Roosevelt Island are the aerial tramway to Second Avenue and 59th Street, and the F train, which residents say is so overcrowded at rush hour that as many as five fully packed trains can pass before any Roosevelt Islanders can get on.

Some developers have been in talks with New York Water Taxi recently about bringing service to the island, local leaders said.