A year-round fairground in Kakaako was approved by a state agency Wednesday, but terms of a lease with landowner Kamehameha Schools remain under negotiation and could limit how much of the $10 million project is developed.

Project developer Billy Balding proposes turning a 3-acre site into an attraction playground that includes a go-kart racetrack, a surfing wave machine, a skateboard park, a seated zip line, an indoor skydiving tower, a rock-climbing wall, a miniature golf course and kiddie carnival rides.

But some of the more expensive and immobile elements, such as the skydiving tower and zip line, would depend on Kamehameha Schools granting Balding longer-term use of the property near Kakaako Makai Gateway Park on Ala Moana Boulevard.

The trust indicated it is negotiating a lease with Balding for one or two years — maybe longer.

Balding said he intends to start with most of the envisioned activities — go-kart racing, the wave machine, skatepark, four carnival rides, an arcade room and party rooms. An initial opening is projected for May but could be pushed back until mid-summer if the state Office of Planning requires a shoreline management area permit.

Balding also said he is exploring whether to relocate the fairground elsewhere, preferably still in Kakaako, if a lease with Kamehameha Schools ends.

The 48-year-old competitive canoe paddler, tow-in surfer and triathlete born and raised in Hawaii said he has received lots of community support for his plan since it has been publicized during the past two months.

"The project will help revitalize the Kakaako area," he said.

The Hawaii Community Development Authority, the agency governing development in the area, held two public hearings on the proposal and received almost unanimous support. The agency’s board voted 8-0 to approve a development permit for Balding. "Thank you board, I really appreciate it," Balding said after the decision.

The block slated for Balding’s project used to be a car dealership but has been largely vacant for several years, except for seasonal uses like a haunted house.

Balding said he has been dreaming of opening a fairground complex for 20 years, inspired by the "kid inside him."

Some activities such as go-kart racing and surfing will require a fee, though he will offer kamaaina rates. Other parts of the park that don’t cost money to run, such as the skatepark, will be free, he said.

Attractions would be available for parties and other events. Operating hours would be from 9 a.m. to midnight.

Balding told the agency that the go-karts he intends to use make less noise — about 70 decibels — than traffic on Ala Moana that registers 80 to 84 decibels.

The zip line with speed control and skydiving tower would be up to 100 feet high. Four kiddie carnival rides, including a Ferris wheel, would all be about 14 feet high.

"It’s not going to be a Coney Island-type 120-foot Ferris wheel," Balding said.

The fairground is slated to serve food from a 35-foot lunch truck with a full kitchen. Alcohol would not be served except for private parties. Parking would be on site with 70 stalls. The operation would employ 30 to 45 people.