The state Land Use Commission is slated to begin hearing a case today for turning 768 acres of farmland in Central Oahu between Mililani and Waipio into a 5,000-home community called Koa Ridge.

The case is basically a do-over by developer Castle & Cooke, which gained LUC approval for Koa Ridge in 2010 on a 6-0 vote. But the Sierra Club Hawaii Chapter successfully sued to overturn the approval on grounds that one commissioner was ineligible to vote.

Under LUC rules, six votes are required to redesignate land from agricultural to urban use.

The day that Koa Ridge was up for final approval, three members of the nine-member commission were absent.

Castle & Cooke hasn’t significantly amended its $2.2 billion project, which in addition to the homes includes a medical campus, two schools, parks, a hotel and commercial space. So the issues up for debate — such as effects on farming, traffic, housing supply and jobs — are the same.

But since 2010, several seats on the commission have been filled by new members. Also, state Sen. Clayton Hee has entered the fray, joining the Sierra Club and the Mililani/Waipio/Melemanu Neighborhood Board in challenging Koa Ridge before the commission.

The hearings are expected to be held a day or two every month or so, stretching the case through several months.

Today Castle & Cooke is expected to begin presenting its case, including testimony from expert witnesses who can be cross-examined. Public testimony also will be accepted.

Later, other parties — the city Department of Planning and Permitting, the state Office of Planning, the Sierra Club, the neighborhood board and Hee — will have the opportunity to present their positions supported by agency officials and expert witnesses.