NEW YORK (CBSNewYork/AP) — Mayor Bill de Blasio and City Council Speaker Melissa Mark-Viverito are developing a plan to close the troubled jail complex that has sat on Rikers Island for 85 years.

“New York City will close the Rikers Island jail facility,” de Blasio said Friday. “It will take many years. It will take many tough decisions along the way, but it will happen.”

READ MORE: Scheifele Has Hat Trick, Jets Beat Devils

The plan would shut down the massive jail within 10 years and replace it with smaller jails, possibly in all five boroughs.

“This is a day New Yorkers have been waiting for,” the mayor said. “This will not be easy, we’re talking about a decade — a decade is a long time. There will be a lot of tough choices, there will be a lot of challenges.”

The move comes as the mayor gives in to the city council speaker and progressive politicians on the left, who have long targeted Rikers as the epitome of what they claim is wrong with the city’s criminal justice system, CBS2’s Political Reporter Marcia Kramer reported. Advocates for prisoners have been arguing that smaller jails, based in the city’s neighborhoods, would be better able to provide services and reduce delays getting criminal suspects to and from court.

“For too long Rikers Island has stood as a symbol of injustice in our city and as a stain on our criminal justice system. It’s legacy of systemic violence and abuse has been a blemish on New York City for decades,” Mark-Viverito said.

It wasn’t immediately clear how local elected officials in the communities where new jails might be built would react. Past attempts to build or expand existing jails in the boroughs have been met with significant resistance from neighborhood groups and others. Governor Andrew Cuomo has suggested using Ward’s Island, Kramer reported.

The mayor said he’s in favor of building as few facilities as possible, WCBS 880’s Mike Smeltz reported.

“Going to be a long process to determine how many facilities we need, where they will be,” he said. “There is no stipulation here. If anyone says, ‘Is there a guarantee there will be a facility in a certain borough, a certain neighborhood?’ No.”

Also unclear is how the politically powerful jail guards union would react to such a plan, which could conceivably shrink their membership.

“This is going to take a lot of work, there’s no quick fix here,” de Blasio added.

To make it work, the mayor said the jail population would have to be cut roughly in half.

“We’ve got about 9,500 people in custody in our entire jail system, that number must get down to 5,000 people to allow us to get off of Rikers Island,” de Blasio said.

The city will also have to reduce crime, the mayor added.

“Reducing crime means reducing jail population. Any talk of getting off Rikers is meaningless if we don’t keep reducing crime,” de Blasio said. “Overall crime is down nine percent if we can continue on that trajectory it will allow us to get off of Rikers Island.” 

In the past, de Blasio had said that replacing the jail would be too expensive. On Friday, he said he had changed his mind because the jail was housing fewer and fewer people, dropping below 10,000 from a high of 15,000 just a few years ago, according to city figures. The de Blasio administration announced this week that they’ve reduced the population at Rikers by 23 percent.

READ MORE: Strome Scores As Rangers Beat Sharks; Shesterkin Hurt

“We came to the conclusion in recent weeks as we looked more and more at the trajectories, we looked at the extraordinary work the NYPD had done, that this goal is more attainable than ever before,” de Blasio said.

Key details of the plan, including the cost and the location of alternative jails, are still a long way from being worked out, the mayor said.

As 1010 WINS’ Al Jones reported, just last year the mayor dismissed the idea of closing Rikers as ‘a noble idea.’ Now, the mayor has a plan — it hinges on first cutting the population in half; 5,000 inmates in 5 years.

“This is going to take a lot of work. There is no quick fix here,” de Blasio said.

Closing Rikers brings up a lot of tantalizing possibilities for the next chapter of what the city will do with the land. Transit experts have long coveted the idea of using it to expand LaGuardia Airport, including lengthening its runways,” Kramer reported.

The announcement comes two days ahead of the planned unveiling of recommendations by an independent commission established in the wake of a string of brutality cases that exposed poor supervision, questionable medical care and corruption at Rikers. The commission, headed by the state’s former chief judge, Jonathan Lippman, has been considering options for Rikers as part of a broad examination of the city’s criminal justice system.

Advocates have been rallying for the shutdown of Rikers since the death of Bronx teenager Kalief Browder, who spent three years in the jail without a trial. He committed suicide after his release.

His mother spoke with WCBS 880 at a court hearing last year just before her sudden death of a heart attack. 

“He went in fine, but when he came out he wasn’t. Solitary confinement destroyed him, said Venida Browder,who fought for reforms at Rikers. “He tried to commit suicide while he was in Rikers and they ignored him. They just felt it was a ploy of him to get out of solitary confinement. That ploy is how he ended his life.”

Rikers is a 400-acre former dump near the runways of LaGuardia Airport. It is accessible only by a narrow bridge between it and Queens. For decades, the city has sent its inmates there while they await trial, where they’re housed in 10 jail facilities.

[graphiq id=”7weqnskXmFT” title=”Rikers Island” width=”600″ height=”750″ url=”” link_text=”Graphiq” ]

The city currently employs about 10,000 correction officers.

A union spokesman didn’t immediately respond to an email seeking comment. The union’s former president was indicted by federal prosecutors last year in a sprawling municipal corruption case. He has pleaded not guilty.

Violence, mismanagement and corruption have been the subject of intense scrutiny by the media and federal prosecutors in recent years.

A 2015 settlement of civil litigation over pervasive brutality led to the installation of a monitor responsible for overseeing the city’s progress in adding thousands of surveillance cameras and stricter policies on use of force.

The Associated Press and other news outlets first exposed conditions on Rikers in a series of reports in 2014 that highlighted violence, poor supervision, questionable medical care and failures to prevent suicides.

Those deaths included a homeless ex-Marine who essentially baked to death in a hot cell and a mentally ill man who sexually mutilated himself while locked up alone for seven days.

MORE NEWS: Nets Escape Timberwolves Behind Durant's 30

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)