Two years after acquiring River Parishes Hospital in LaPlace, Ochsner Health System is joining with Acadia Healthcare Co. to convert the building into an 82-bed inpatient behavioral health facility.

The move is expected to create dozens of much-needed beds for treating psychiatric patients across south Louisiana.

Offering such care is an expensive proposition for private health care companies like Ochsner, industry experts say, but years of budget cuts that forced the closure of many state-owned beds have created a pent-up demand for new facilities.

There’s “a huge need for mental health services” across the metro New Orleans and Baton Rouge areas, Ochsner President and CEO Warner Thomas said.

Ochsner, the state’s biggest nonprofit health care company, already had said it would build a new $12 million medical facility near Tiffany Drive and Airline Highway in LaPlace.

That 20,000-square-foot, 13-bed medical facility, which will offer emergency and primary care services, is slated to be finished next year, Ochsner said.

Now, Tennessee-based Acadia Healthcare will spend $16 million to $18 million to convert the old hospital in LaPlace into a psychiatric care facility, which is expected to open in 2018 and treat an average of more than 60 patients a day.

In announcing the project Wednesday, executives noted that Louisiana ranks 39th in the U.S. for providing access to substance abuse care and mental health treatment. Recent estimates show that more than 400 new beds are needed in southeast Louisiana, they said.

“We’ve really never had enough space in our existing facilities,” Thomas said, “and once this opportunity presented itself, we viewed it as a great way to move forward and get this expansion done.”

Last year, Ochsner transferred more than 4,000 patients from eight of its emergency departments across the region to other facilities for psychiatric care, Thomas said. Having the mental health treatment center in the Ochsner fold will cut down on transfers, provide continuing care for patients and create a new revenue source for Ochsner.

It often takes time — sometimes several days — for an emergency room to track down a local behavioral health facility with an open bed, said Walter Lane, an associate professor at the University of New Orleans who studies health care economics.

“It’s very difficult to find a placement, so having some extra beds in that area will be a big help to a lot of people,” Lane said.

Locally, the state’s controversial 2012 decision to privatize the former Southeast Louisiana Hospital in Mandeville left state-owned facilities for mental health care only in Pineville and Jackson.

St. Tammany Parish officials ultimately moved to purchase the old Mandeville facility from the state with an eye toward turning it into a “one-stop shop” for mental health.

Already at that site, Northlake Behavioral Health System operates a 140-bed inpatient psychiatric facility, according to Richard Kramer, Northlake’s CEO.

Kramer agreed that more psychiatric beds are needed and said his facility plans to add another 20 later this year.

“We stay pretty full most of the time,” he said.

The bed shortage is due largely to the high cost of providing the service, according to Lane. “Most places are reluctant to do psychiatric services because it’s just a service line that you tend to lose money on,” he said.

Ochsner acquired the then-underused LaPlace facility from LifePoint Hospitals in late 2014.

In addition to the new medical offerings, the two LaPlace projects are expected to create 145 jobs in St. John the Baptist Parish. Parish President Natalie Robottom described the new effort as “an economic boon to our area.”

Acadia provides inpatient psychiatric and chemical dependency services through a network of 587 facilities in 39 states, the United Kingdom and Puerto Rico.

Follow Richard Thompson on Twitter, @rthompsonMSY.