Over the past 10 years, New Orleans has shed several thousand inmates from its jail. Now, city officials are pledging to bring the population down even further with the help of a $1.5 million grant announced Wednesday by the John D. and Catherine T. MacArthur Foundation.

On any given day, the city holds roughly 1,600 inmates in two jail buildings in Mid-City. As part of the new grant, New Orleans has pledged to cut that figure by 27 percent within two years, a goal in line with the City Council’s declared intention to house all city inmates in the new $150 million, 1,438-bed Orleans Justice Center.

New Orleans was one of 11 cities nationally to receive one of the foundation’s latest Safety and Justice Challenge grants.

“These jurisdictions have committed to aggressive targets and are not only flattening out the curve of jail use; they’re bending the curve,” said Laurie Garduque, MacArthur’s director of justice reform. “It’s a huge departure from business as usual.”

Garduque noted that the foundation’s grants are coupled with technical assistance and oversight. After two years, cities that have made progress may be eligible for more money.

Like most other MacArthur grantees, New Orleans is promising to address racial disparities within the criminal justice system, expedite court processing, improve police-community relations and tackle health care gaps that often land people in jail after a mental health crisis.

Police Department crisis-intervention teams will use a prebooking diversion process to place people in crisis directly into the mental health care system instead of in jail, said Charles West, who heads the city’s Innovation Delivery Team and oversees efforts to reduce the jail population.

To push down the number of pre-trial inmates, West said, local courts will begin reviewing the bail levels set for inmates who have been held for seven days without making bail, with the possibility of setting the bail at a level they can afford.

At present, magistrate judges release about 26 percent of low-risk defendants and about 3 percent of moderate-risk defendants without bail.

To counter racial bias, the grant says, New Orleans must implement “implicit bias training,” something already mandated by a federal consent decree governing reforms at the Police Department.

These new efforts to reduce the inmate population may influence the ongoing debate about Sheriff Marlin Gusman’s proposal for a so-called Phase III facility to accommodate special-needs inmates. Mayor Mitch Landrieu has opposed the idea of another building, saying the hurricane recovery dollars that would pay for it could be better used elsewhere.

Hitting the target outlined in the MacArthur grant for reducing the jail population would strengthen the argument for avoiding more construction.

The MacArthur grants are designed to reverse long-term trends. Since the 1980s, jail populations across the country have more than tripled. Costs footed by local taxpayers also have tripled, as many sheriffs used public bonds to build huge jails, which required bigger operating budgets.

New Orleans was a textbook example. Before Hurricane Katrina, the Orleans Parish Prison complex encompassed 12 buildings and 7,673 beds, making it the ninth-largest local jail in the nation, far out of proportion with the city’s size.

Efforts to shrink the local prison population have been underway for years.

West convenes regular meetings of the city’s Jail-Population Management Subcommittee, which includes representatives from all of the criminal justice system’s components: the jail, courts, the City Council, and probation and parole offices.

Given all the players involved, though, the task of reform is complicated, involving intricate “system mapping” — basically, a flow chart of every criminal justice decision made by local police, jailers, judges, prosecutors, public defenders, policymakers and probation officers.

In 2010, under pressure from community activists and council members, a mayoral task force began looking at what groups were being needlessly held in the city’s jail. Today, many of the largest targets have been resolved. Earlier this year, for example, the sheriff sent away almost all of the state-sentenced prisoners who were being housed in the jail; their presence there had long been a point of debate.

Another significant stride came when a change in city law gave police the authority to issue summonses — notices to appear in court — instead of making arrests for minor violations.

In 2014, nearly 12,000 summonses were issued to people who otherwise would have been jailed. Summonses were given to most of the 1,250 people facing first-time marijuana possession charges in 2014; only 346 people, or 28 percent, were physically arrested.

Correctional expert James Austin also found that in 2010, about 10,000 people were stopped in New Orleans and jailed for non-felony, out-of-parish warrants, often for unpaid traffic fines and fees. That practice has largely stopped; last year, only 1,285 such arrests were made.

Now, instead of a carving knife, West’s subcommittee must use a scalpel in trying to further reduce the jail population. For instance, the group hopes to implement a system to remind defendants before scheduled court appearances because judges issue warrants for defendants who miss court dates. By reducing the number of defendants who fail to appear by 20 percent, the jail population could be reduced by 1.5 percent.

Similarly, as of November, probation and parole officers no longer have to arrest people under their supervision for certain technical violations. Instead, the officers can dole out community service or other sanctions on their own. That could bring the jail population down by 1.5 percent within three years.

Although the city’s local incarceration rate is still twice the national average, West predicts that New Orleans will reach the national average in two years, at about 1,000 inmates.

Garduque, of the MacArthur Foundation, believes that goal is reachable after two more years of exacting work. “It’s not like there is some hot new app that enables cities to reduce their jail population,” she said. “It’s an arduous process.”

Editor’s note: This story was altered on April 15 with corrected statistics on the number of defendants in New Orleans who are released without bail.