State senators approved new maps for their districts on a 36-3 vote Wednesday, with two of those who voted in opposition raising concerns about both their individual districts and the process behind the changes.

Sen. William Brownsberger, the lead architect of the Senate's redistricting plan, said it doubles the number of districts where a majority of residents are non-white -- from three to six, out of 40 -- and reduces the number of muncipalities split between multiple districts.

Late U.S. Census data this year put lawmakers on a condensed timeline for redrawing their districts, and Brownsberger said a process that normally takes about half a year was done in less than two months this cycle.

"It's moved very fast, and it's kept changing right up until the end. I think we've got a good final product. It's a quality final product," the Belmont Democrat said. "I don't want to say it's rushed, but we've used every moment we've had to keep vetting, to keep adjusting, and to keep recognizing new issues and to respond to them."

That response included late changes to southeastern Massachusetts districts currently represented by Sens. John Keenan, Marc Pacheco, Paul Feeney, Walter Timilty, Susan Moran and Mike Brady, Brownsberger said.

Pacheco voted against the redistricting bill (S 2560), as did Merrimack Valley Sens. Diana DiZoglio and Barry Finegold. All three are Democrats, and the chamber's three Republicans voted in support.

The current Senate districts, Brownsberger said, features 21 communities split between multiple districts. The new version "un-split" 12 communities and divided two new ones, he said, for a total of 11 left separated.

The original proposal the Redistricting Committee presented on Oct. 12 sought to add two new majority-minority Senate districts, prompting pushback from advocates who had hoped to see another in the Brockton area. After what Brownsberger described as some "stretching to meet the concerns of advocates," the map approved Wednesday created a new majority-minority district combining Brockton with half of Randolph and Avon.

"This is the power of a fair and transparent redistricting process -- community members, advocates and local officials made their voices heard and demanded more equitable representation for BIPOC, immigrant and low-income communities in Massachusetts, and the Redistricting Committee listened," said Beth Huang of the Drawing Democracy Coalition and the Massachusetts Voter Table. "As a result, BIPOC voters across the commonwealth, and particularly in Brockton and Lawrence, will have greater opportunity to elect candidates of their choice."

Lawrence, which has the largest share of nonwhite residents in the state, will be separated from its mostly white neighboring town of Andover, and joined with Methuen and parts of Haverhill to create an incumbent-free majority-minority district.

Brownsberger said that change will allow the new district's Hispanic majority to elect a candidate of its choice. The state Senate is overwhelmingly white, with people of color holding only two of the 40 seats -- Sen. Adam Gomez and Sen. Sonia Chang-Diaz, who is running for governor next year and therefore not seeking re-election.

Before voting against the map, Finegold, of Andover, offered a farewell to Lawrence in both English and Spanish and said he would continue to fight for the city, highlighting legislation addressing issues like community hospital support, auto insurance inequities and the digital divide. He said Spanish-speaking Lawrencians have dubbed him "Senador Oro Fino," a translation of "fine gold."

"Helping out the city of Lawrence has been my life's work," he said. "About 10 years ago, Boston Magazine called Lawrence the city of the damned, and that piece overlooked some of the city's most important resources. Lawrence is very rich in character, drive, optimism and commitment, and together in these last 10 years, we have proven the naysayers wrong."

Haverhill is currently represented by one senator, DiZoglio. Officials there, including Mayor Jim Fiorentini and Rep. Andy Vargas, who is running for Senate, have knocked the plan to divide it into two districts.

DiZoglio, who is running for auditor, said communities like Haverhill that have "been cut into pieces" need to have their voices heard and floated the idea that the Senate take more time to consider the issue. She said some members of her community have shared with her the idea that "there appears to be a correlation" between the districts least affected by redistricting changes and those represented by leadership.

DiZoglio said the bill is a "laudable, critical first step" that makes "important progress in representation" but does not "guarantee something beyond a voice -- true access to influence and power, and that goes for our communities of color and many other communities in Massachusetts that have been shut out for too long."

Brownsberger said splitting Haverhill was "not done lightly but done because we need all the Hispanic voters in Merrimack Valley together to create an effective district in which they will have the ability to elect the candidate of their choice."

He said that while there are good reasons behind trying to reduce the number of divided communities, some municipalities see a benefit to having two senators to represent their interests.

Pacheco, of Taunton, objected to the breaking apart of two towns he represents that share a regional school district, Bridgewater and Raynham.

He said the attempt to unite previously split communities "created a domino effect" in the southeastern region of the state, and said those districts would not have needed to be "disrupted" if a few more communities remained split among districts.

"Instead of 21 to 11, maybe it was 21 to 15," he said. "What is the cost of bringing those communities together? Was that the cost of splitting the Bridgewater-Raynham school system in terms of representation? That's almost like splitting the town."

Pacheco also said that the two business days between when the redistricting bill first officially surfaced in the Senate last Thursday and a Monday afternoon amendment deadline "was not a real open process."

The only amendment filed to the bill came from Brownsberger, who said he offered it to fix errors created during a cutting-and-pasting process used to translate data from the committee's mapping software into legislation. The amendment was adopted on a voice vote.

The Senate on Thursday also passed a bill redrawing the 160 House of Representatives district boundaries, which the House green-lit last week on a 158-1 vote. The House will similarly need to vote on the Senate's maps.