A state commission yesterday allowed an affiliate of Gentry Cos. to draw water from a Central O'ahu aquifer to irrigate two golf courses proposed as part of the company's master-planned Waiawa community.

The controversial decision will allow Gentry to proceed with planning the 3,700-acre Waiawa project, where 10,000 to 12,000 homes are envisioned, and move ahead with golf course and infrastructure construction in the next six to 12 months. Water from the aquifer is suitable for drinking.

The Commission on Water Resource Management unanimously approved a staff recommendation to allow Gentry's Waiawa Development LLC and landowner Kamehameha Schools to pump about 1 million gallons a day from the Waipahu-Waiawa aquifer to serve the two 18-hole golf courses.

The approval came with a commitment by Gentry to switch to an alternate source of nonpotable water, such as treated wastewater, if such a source becomes available.

Still, the approval to pump groundwater disappointed Jeff Mikulina, director of the Sierra Club Hawai'i Chapter.

"Something's not right," he said. "It is foolish to be allocating our limited fresh water to water a golf course, particularly as the Board of Water Supply is asking residents to conserve."

The Honolulu Board of Water Supply constantly urges residents to conserve water, and said earlier this year that a five-year drought that peaked in 2001 left aquifers at dangerously low levels.

"We are draining it (water) far faster than nature can replenish it," the board says on the home page of its Web site. "We must always conserve and protect the water supply entrusted to us."

According to the state commission, the Waipahu-Waiawa aquifer has a sustainable yield of 104 million gallons a day. About 56 million gallons a day are used, suggesting that the aquifer would not be threatened by the proposed golf course use of about 1 million gallons a day. Islandwide use has ranged from about 130 million gallons per day to 155 million over the past few years

"I don't think we're putting any strain on the aquifer," said David McCoy, president of Waiawa Development and a former Campbell Estate chief executive.

McCoy said the permit approval was significant for the Gentry project, which has been in the works since the mid-1980s.

"It was the only source we had to irrigate the golf courses," he said. "If we hadn't succeeded (obtaining the permit) we wouldn't have had golf courses. The project would have proceeded whether we had golf courses or no golf courses, but it's a nice amenity for the people who will live there."

Irrigation for Gentry's planned Waiawa golf courses has been a source of contention for years.

In 1999, landowner Kamehameha Schools asked to supply the Waiawa project using the 25-mile Waiahole Ditch system that diverts water from Windward streams to Leeward O'ahu for primarily agricultural use.

But that proposal, which sought 4.2 million gallons of water a day to irrigate the golf courses, parks and other landscaped areas of the Gentry Waiawa project, ran into opposition from environmental and community groups that led Kamehameha Schools to withdraw its application in 2002.

The alternative to tap groundwater didn't raise as much opposition, though the Sierra Club still questions whether enough water exists in the WaipahuWaiawa aquifer to satisfy all planned development in Central O'ahu, which includes other master-planned communities like Castle & Cooke's Koa Ridge.

Gentry said it has approvals to supply drinking water to its planned Waiawa homes. Initial homes and one golf course are projected to be completed in 2008.

Reach Andrew Gomes at agomes@honoluluadvertiser.com.