The Arlington County Board Saturday voted 3-2 to pay for the planned Columbia Pike streetcar without federal funding, deciding to rely instead on $65 million in additional money from the commonwealth to help cover the project’s estimated $333 million cost.

Forgoing the federal funds and the requirements that go along with them is expected to speed the project up by as much as a year and save the county at least $25 million.

The contentious split was a turnabout for the board, which was once known for its 5-0 votes and near-unanimous opinion on how to manage growth and transit. Leading up to the vote, members read prepared statements alternately supporting the project as smart planning for future growth and attacking it as an unwise investment of public money.

A few days earlier, a normally routine meeting in which board members were finalizing their changes in the county manager’s biennial Capital Improvement Plan recommendations turned into three hours of verbal barbs and accusations. The anti-streetcar coalition of John Vihstadt (I) and Libby Garvey (D) tried, but largely failed, to stop all spending on the project. The battle overwhelmed debate on the $2.7 billion CIP, which will fund infrastructure work for the next decade.

Tempers had cooled somewhat by Saturday. Streetcar supporters County Board chairman Jay Fisette (D), J. Walter Tejada (D) and Mary H. Hynes (D) argued for Arlington’s history of careful planning and execution of projects, and the expected economic growth streetcars would bring. They also cited the need for better mass transit in an area likely to boom in both residents and jobs during the coming decades.

“If we don’t do this, . . . we become a bottleneck for the region and we become a far less wonderful place to live,” warned Hynes.

Tejada, who was vice chairman two years ago when the board approved a plan that tied new development in the Columbia Pike area with saving 6,200 currently affordable apartments, said “It’s always easy to denigrate, criticize, attack, oppose and create a negative environment. . . . We are creating plans for all the generations to come.”

Fisette noted that most of the money used to build the Columbia Pike streetcar can’t be used for other priorities. The streetcar corridor, he said, will attract more than three times the private development that an enhanced bus system would. He appealed to Arlington residents to “look into the detail beyond the narration and sound bytes, look at the benefits to the county.”

Opponents were just as firm. Garvey asserted that most of the public relies not on “facts, but on common sense.”

“Common sense tells them arguments for the streetcar do not add up,” she said. The majority has voted not to hold a citizens’ referendum on the matter “and says the time for discussion is long past . . . but we also need to be respectful of where the public [opinion] is now.”

Vihstadt, who won his seat in a special election in April, called the streetcar an “albatross” and “an unwise public expenditure.” Vihstadt, who is running for re-election to a full board term in November, also pushed back against those who decry the split votes.

“It is wrong to characterize vigorous debate and dialogue about fundamental policy and spending issues involving hundreds of millions of dollars as being divisive and somehow inappropriate. In fact, such debate is essential in a pluralistic and diverse community,” he said.

The project, which has been in planning stages for about a decade, is slated for completion in 2020.