The Anchorage Assembly voted unanimously Tuesday to allow the Port of Anchorage to borrow $75 million to pay for the beginnings of a massive port makeover project.

The port plans an expansion that would include a 1.5-mile steel wall, backed with millions of cubic yards of gravel and sand, creating 135 acres of new land in Knik Arm. It would be the biggest public works project in the history of Anchorage.

The Assembly, including four new members who took office Tuesday night, held a public hearing before voting. Five of the six people who spoke urged the Assembly to take a closer look at the project before allowing it to move ahead.

Port director and former Gov. Bill Sheffield said Tuesday the project would cost more than $700 million, up substantially from an estimate last year of $375 million.

"That's double the cost stated just last year. How much will it be next year?" asked Julie Jessal, president of the Government Hill Community Council.

Jessal and others said the project has never been subjected to the kind of in-depth environmental review that such a big project demands.

Mike Adams, manager of a Chevron terminal at the port, spoke in favor of the project. The port is important for military and statewide cargo needs, and delaying the expansion would only increase the labor and construction costs, he said.

The port project would be built in phases. Assemblyman Patrick Flynn said the money being discussed would allow for construction on the north end of the port and that the city can decide later whether to keep pursuing the project.

Assemblywoman Sheila Selkregg asked if building one phase of the project commits the city to paying for the whole thing. Sheffield said no.

The port's records show that the number of tons of goods crossing the port has decreased in recent years, Bob Shavelson, director of the environmental group Cook Inletkeeper, told the Assembly.

Sheffield said that was true because a refinery in North Pole had stopped shipping a petroleum product called naphtha through the port, but that the refinery planned to start making the fuel again, which should solve the problem.

In an interview, Sheffield said that if the port project goes as planned, it could be finished by 2014. Asked why costs estimates increased so much over the past year, he said: "We're doing more than what we were going to do, and it's costing us more than we thought it was going to cost."

Find Kyle Hopkins' political blog online at adn.com/alaskapolitics or call him at 257-4334.