A state agency is gearing up to preserve privately owned farmland potentially covering 11% of Oahu in an unprecedented process that could draw landowner challenges.

The state Land Use Commission is preparing to hold public hearings starting Feb. 24 to carry out its responsibility under a 2005 state law aiming to protect high-value farmland statewide by essentially locking up such land for agricultural use in perpetuity.

The law was a belated response to a Hawaii Constitution amendment ratified by voters in 1978 mandating that prime agricultural lands be identified and protected.

Under a 2008 add-on to the 2005 law, private landowners were allowed to voluntarily protect high-value farmland they owned in return for benefits that included tax credits, loan guarantees and blocking half of any such land holdings from forced preservation.

Many of Hawaii’s largest private landowners — Kamehameha Schools, Alexander &Baldwin Inc., Parker Ranch, Castle &Cooke Hawaii, Molokai Ranch, Kualoa Ranch, Grove Farm Co., Monsanto and others — did so.

Now the involuntary piece of the 16-year-old Important Agricultural Lands law is on the verge of being implemented.

The law directed county government officials to identify land appropriate for preservation under criteria that include soil quality, water supply and use.

The City and County of Honolulu was the first to complete its part of the process, and in 2019 recommended that 41,407 acres on Oahu be protected.

Oahu covers 386,188 acres, of which about 128,000 are classified as agricultural, including 12,300 acres voluntarily protected by private landowners.

The land up for protection now is made up of 1,781 parcels with about as many owners, and is spread around the island, with the biggest concentrations in Kunia, Wahiawa, Mililani, Haleiwa, Waialua, the Waianae Coast, Waimanalo and from Kahaluu to Kahuku.

The parcels were selected in a process that included an analysis of suitable lands, community and focus group meetings, notification to the roughly 1,800 landowners, a formal comment period, City Council hearings and Council approval.

The LUC may approve, modify or reject the city’s plan, which was submitted to the commission in September.

However, this pivotal step may be a shaky one.

“We’re trying to figure our way through this,” Daniel Orodenker, the LUC’s executive director, told commission members at a Thursday meeting. “To be kind, this was a poorly drafted piece of legislation.”

Some LUC members anticipate that a number of affected landowners may challenge a forthcoming decision by the commission, and questioned a state lawyer about how such challenges would be handled.

Challenges could be appealed to state court or possibly handled in similar fashion to a contested-case hearing before the LUC, with the ability of affected landowners to challenge city decisions with expert witnesses under a quasi-­judicial hearing process.

Commissioner Lee Ohigashi raised a concern over the LUC spending years addressing a potentially large number of challenges.

“It is what it is,” Orodenker replied.

Orodenker noted that some lawmakers ignored concerns raised over the legislation before it became law, and that an idea to fix perceived flaws in the law with a future amendment was never carried out.

In one instance, Orodenker said, he got a shrug from one lawmaker in response to a question about who would defend the city’s decision and how.

“We have to use our best efforts, our best conscience and the advice of counsel to determine how we ought to handle this, because it has not been tested,” he said.

The LUC was assigned its role, in Orodenker’s view, to remove politics from the matter by not leaving a final decision to elected officials.

In its role, the LUC must consider whether the city’s designation of important agricultural lands was appropriate. The commission is expected to give much deference to the city because the commission’s role isn’t to redo what the city did.

While the city was carrying out its work over roughly seven years, tempers at community meetings at times grew heated.

“People are wanting more or wanting less,” then-Mayor Kirk Caldwell said in 2018. “Everyone seems to be upset one way or the other.”

The state Department of Agriculture, which participated in the city’s effort in part by serving on a technical advisory committee, recommends the LUC approve the city’s protection plan.

“The Department of Agriculture believes the process utilized by the city leading to the development of the final maps was deliberate and thorough,” the agency said in a Tuesday memo.

The state Office of Planning commended work by the city Department of Planning and Permitting and City Council, but did not endorse the entire protection plan.

In a Wednesday memo, Office of Planning Director Mary Alice Evans raised issues with protecting many parcels less than an acre in size and land with slopes over 20%, asking for clarification from the city before rendering a fuller opinion.

The LUC anticipates its initial public hearing largely to receive information from city officials and other agencies will be followed by a second hearing to hear from landowners and other interested parties before a third hearing for decision-making.