St. Tammany Parish officials expect Safe Haven, a behavioral health campus planned on the site of the state’s former mental hospital near Mandeville, to save public agencies millions of dollars a year by diverting people in crisis from emergency rooms and jail cells.

The parish on Wednesday revealed the master plan for Safe Haven, a 25,500-square-foot crisis intervention center where police, family members and hospitals will be able to send people suffering a mental health crisis.

The center will include a triage unit, a psychiatric observation and respite unit and what’s known as a social detox unit, which offers detoxification that doesn’t involve the use of medicine.

A second phase would expand the offerings to include outpatient treatment.

The estimated cost of creating the center is $5.5 million.

Parish President Pat Brister, who has been a driving force behind the project, said St. Tammany sold the inpatient hospital that is already on the campus to the private operators who have been running it since the state closed its facility.

That sale and the sale of some land to Pelican Park have helped the parish recover some of the costs it incurred when it bought the 293-acre property for $15.4 million in 2015. St. Tammany also is using part of the property as a wetlands mitigation bank, which is helping to reduce the parish’s costs.

The actual financing for the project will come from multiple sources, including grants, parish spokesman Ronnie Simpson said.

The parish hired the consulting firm Kurt Salmon to help guide the planning process, which began last year with an assessment of the community’s needs and interviews with many of those involved in mental health, including providers, patients and family members.

A planning group also looked for innovative models elsewhere and zeroed in on two, San Antonio’s Haven for Hope and Eskenazi Health Midtown Community Mental Health in Indianapolis.

Consultant Leslie Marshburn said St. Tammany’s master plan draws on elements from both models.

Facing the need for an additional 1,000 beds in its jail system, Marshburn said, San Antonio turned to an approach aimed at diverting mentally ill people away from the criminal justice system and into treatment. The result was savings to taxpayers of more than $10 million and an 85 percent reduction in homelessness, she said.

In St. Tammany, planners saw a lack of access to care, a fragmented behavioral care system and a reliance on jail and emergency rooms, Marshburn said. But they also found strong community support for addressing the issues.

St. Tammany Parish has about 2,160 annual visits to hospital emergency departments that are related to behavioral health, Marshburn said. In the first quarter of 2016, 19 percent of the people who were booked into the parish jail had a mental health issue, she said, and 65 percent of inmates had substance abuse problems.

The consultants estimate that Safe Haven will have 5,000 visits per year and will save $3.2 million a year in costs to emergency departments and from $3.3 million to $6.9 million in jail costs.

Earlier intervention and better access to care will help reduce mental health crises, Marshburn said, noting that patients typically have suffered from mental illness for eight to 10 years before they have their first treatment.

Planning will continue throughout 2016, Marshburn said, and 50 percent of the first phase will come on line through 2018.

But services offered by other entities will be available sooner. NAMI St. Tammany, which already has a presence on the campus, will open a drop-in center by June 2017, President Nick Richard said. That facility, which will be open Monday through Friday, will offer support groups, activities and other help.

Family Promise, which helps homeless families, will have a day center on the campus by the end of 2017.

Follow Sara Pagones on Twitter, @spagonesadvocat.