There’s only one sheriff in town, but it is clear enough that Marlin Gusman is giving up much of his responsibility for operations of the long-troubled Orleans Parish Prison.

A new appointee, approved and answerable to the U.S. District Court, will take over operational control of the new jail. Judge Lance Africk approved a settlement of disputes that stops short of a formal federal takeover.

But not far short.

Mayor Mitch Landrieu has long clashed with Gusman over the costs of the jail and the sheriff’s plans for what the administration considers grandiose expansions of jail capacity. The mayor said Wednesday that he hopes a new compliance director will get a handle on costs.

Who will get this daunting job? It will be a selection of Gusman’s but only after a nominating process, which includes the mayor, produces a short list of names approved by the court. Landrieu characterized the process as a victory because under Africk’s order, the new director will have wide-ranging authority.

The director will make the decisions, “including authority over the entire prisoner population.” The sheriff is to be consulted unless that would cause “unreasonable delay” in carrying out reforms, the order said.

This is a major new step in the jail saga, but it is important to remember that the goals of the new compliance director are those established by the court and the sheriff in the consent decree of three years ago.

That a new director was ordered by the court shows that Gusman has not made the progress in remedying the disorder in the prison that Africk’s rulings suggest is unconstitutionally inhumane. It’s still a big job ahead. Whoever sits in the Sheriff’s Office, or the Mayor’s Office, or the compliance director’s chair, the jail population is a tough managerial challenge.

“This is not unlike delegating authority that I do for a lot of the people I work with,” Gusman said of the order. “The compliance director and I will work closely together to move the Orleans Parish Sheriff’s Office swiftly toward compliance” with the consent decree.

If he does that, working in good faith with the new director, the people of New Orleans will be better served. But the sheriff’s face-saving statements do not change the fact that the court will be overseeing whether the Sheriff’s Office is collaborating with the new director.

The whole mess suggests the taxpayers of New Orleans would be better off if a future mayor controlled both the budget and operations of the jail, so voters — or a judge — can hold one elected official responsible when things go wrong.