Acquiring properties in Honolulu to build Oahu’s rail transit system could involve "judicious" use of eminent domain, officials say, as those overseeing the project scramble to secure ownership of all the properties they’ll need to keep construction on schedule.

"We won’t hold up the project," Honolulu Authority for Rapid Transportation Executive Director Dan Grabauskas said Thursday after HART’s board meeting, held this month at Kapolei Hale. "If our negotiations haven’t gone to where they need to be, or aren’t going in the right direction, then we may concurrently file for eminent domain."

Grabauskas and HART staff say they’re aiming to do some 18 months of work negotiating those properties in only six months’ time. They intend to purchase approximately 146 full or partial properties in the heart of Honolulu by Dec. 15 to keep construction on track in 2015.

A court-ordered injunction in the federal lawsuit to stop rail, enacted at the end of 2012 and lifted in February, has them far behind where they should be.

On Thursday, HART officials presented the board with an early outline of an emergency plan that could cost as much as $5 million to ramp up property acquisition in the six-month compressed time frame. It involves 16 new hires, including property acquisition and relocation specialists, and clerks to handle the added paperwork. It also calls for added help from consultants for surveying and mapping, as well as more city legal support.

Rail officials blame those who brought the suit for costing the project at least several million dollars in added costs to get the properties. Those opponents contend that it was the city that caused the delay by dragging out court proceedings to make that action more difficult for plaintiffs.

The city has spent more than $61 million to purchase 67 properties for the rail project so far. All of those parcels are west of town, and many of them come from other public agencies, HART officials report.

So far none has been acquired through eminent domain — although rail officials started proceedings for that action against two properties in the so-called Banana Patch area, a rural neighborhood near where Farrington and Kamehameha highways intersect. They’re still working toward a settlement to potentially avoid eminent domain in those cases, Grabauskas said Thursday.

But the pressure to purchase most of the properties needed to build rail in such a tight time frame — and most of them in the heart of town — could mean added eminent domain proceedings in the near future, rail officials acknowledge.

"We just wanted to be transparent that that might be something we look at doing as we move forward … if we get to a point where scheduling becomes very, very critical," Elizabeth Scanlon, HART’s director of planning and right-of-way, told the board Thursday.

It could be another two or three months before rail officials working on right-of-way issues know whether they’ll need to use eminent domain, Grabauskas said.

Often, when government entities build large public works projects such as a new highway — or, in this case, Oahu’s 20-mile, 21-station rail line — they have the right to acquire any private properties in its path (and compensate the owner) to complete the project. The process is widely known as eminent domain.

Many of the property acquisitions for the island’s elevated rail lines are needed so that crews can widen local roads where the guideway will run, or to build power stations and other facilities to support the transit system.

The list of properties in town, held by 81 different owners, is a "moving target" that could further fluctuate based on the transit system’s final design, rail officials say.

They add that they won’t provide a final list until design work is completed, sometime late this summer or early this fall. No property owners spoke at Thursday’s board meeting.

The monthly meeting is held in Kapolei every several months or so to provide West Oahu residents better access. Holding it in Kapolei on Thursday, however, pushed the discussion on Honolulu property acquisitions some 20 miles west of town.

All 81 owners have been notified of the need to use some or all of their property, and in some cases HART has started the "conversation" to acquire, Grabauskas said.

Scanlon and others overseeing the right-of-way effort are expected to provide more details and an update to the board next month.