The state has already spent nearly $10 million on planning, permitting, environmental reports and other tasks related to development of a new jail in Halawa, according to a consultant working on the project.

Bettina Mehnert, president and CEO of the firm AHL, formerly known as Architects Hawaii, disclosed that substantial sum during a briefing for the Hawaii Correctional Systems Oversight Commission on Thursday. But the planning money is just a small down payment on the larger project.

State consultants estimated in 2017 the total cost for the new jail would be $433 million to $673 million, ranking it among the most expensive state projects ever. Current plans call for a facility with room for about 1,044 jail inmates and another 288 convicts who are approaching their release dates.

Last December the commission asked the state Department of Public Safety to pause the planning for a new jail to replace the aging Oahu Community Correctional Center, partly because commission members want the state to reconsider the size of the new jail.

But Max Otani, acting director of the state Department of Public Safety, told the commission in January and again on Thursday that work on the project will continue.

Lawmakers appropriated a total of $10.4 million for planning and construction of the new jail in 2014 and 2016, and Otani has told the commission that “because we were given the funds, we’re proceeding as appropriated.”

The $10 million in planning expenses for the jail disturbed critics of the jail project including Robert Merce, who served on a task force on correctional policies led by state Supreme Court Associate Justice Michael Wilson.

That task force strongly recommended policy changes such as diverting petty offenders into mental health services, drug treatment or other programs instead of jailing them, and releasing more of the inmates who are locked up at OCCC because they cannot afford to post bail.

Adopting those changes would reduce Oahu’s jail population significantly and save the state money, he said.

“We aren’t considering any of these things, and I can’t believe we’re $10 million into this plan without looking at those very basic, fundamental things; it’s time that we start considering those things, because they’re going to impact our community for a generation,” Merce said. “I just can’t believe it.”

Mehnert said the planning for the new jail is largely based on existing policies and laws, “but we are trying to anticipate” possible changes. She said planners are in the “final stages” of a new jail population forecast for the next 10 years because the last forecast for the project was done in 2016.

To date the planners have produced an OCCC master plan, draft and final environmental impact statements, and various reports on the progress of the project. There was also a site selection process that concluded the Animal Quarantine Station in Halawa is the preferred location for the new lockup.

The city issued a plan review use permit for the project, and Mehnert said there were also geotechnical borings and hazardous materials studies of the old quarantine structures that will need to be demolished.

The Department of Accounting and General Services also issued a request for interest earlier this month to try to gauge how many companies would be interested in financing and building the new jail.

Interested developers, financiers and investors are being invited to submit their credentials as well as their assessments of the risks and challenges involved in the project. Mehnert said there will be a “business case analysis” to determine the best way to finance and proceed with the project.

So far lawmakers have been unwilling to put up the hundreds of millions of dollars in state money that would be needed to publicly fund construction of the new jail, so the state is investigating whether a private partner would be willing to finance the project.

OCCC is the largest jail in the state, and corrections officials say it is run down, has an obsolete and inefficient design, and has been overcrowded for years. It has an operational capacity of 954 inmates, but as of Feb. 15 was holding 934 prisoners.