After about two years of delays, the state's sand replenishment project at Kuhio Beach is set to begin next month.

State Department of Land and Natural Resources officials said they're still finalizing a start date, which will be sometime in mid- to late October.

"We want to make sure ... that the summer swell is essentially over," said DLNR chairman Peter Young. "We don't want to pump sand up onto the beach and then have a swell just take it back out."

The replenishment project will be the largest in more than three decades at the beach, which experts say has eroded by about a foot a year since 1985, the state has said.

The sand replenishment was originally supposed to begin in the fall 2004, but was repeatedly postponed because of issues including permitting and equipment delays and, most recently, the March sewage spill in the Ala Wai Canal. State officials pushed the project back to the fall to avoid the summer south swell.

The $500,000 project will take about 30 days and will deliver about 10,000 cubic yards of sand dredged from offshore to Kuhio Beach. American Marine, which dredged the Ala Wai Canal in 2003, is contracted to do the work.

The process involves mooring a barge about 2,000 feet offshore above a sand bank identified in a University of Hawai'i survey as having plentiful, clean sand. The barge will be equipped with a hydraulic sand dredge and connected to a submerged pipeline system to the beach. The sand will be pumped to a retention basin on the beach, where it will be allowed to dry. Heavy equipment will push the sand to areas that need it on Kuhio Beach.

About 250,000 cubic yards of sand have been added to the beach at Waikiki since the 1930s, according to the state. Much of that has been swept away by currents and moved offshore. The last major beach "nourishment" effort was in 1975, the department said.

"Waikiki is a built beach; it's had sand added to it (and) that sand has gone offshore into these pockets, so we want to use it rather than just trucking sand in and dumping it," Young said.

During public hearings on the project two years ago, George Downing, a founding member of the group Save Our Surf, and beach concessionaires expressed concerns that removing the sand below surf spots would affect the waves and asked that a study be done.

State officials conducted a test and also monitored the currents "to see what happens with the sand movement," Young said. Officials determined the waves would not be affected.

"We expect everyone will be happy," Young said.

Reach Lynda Arakawa at larakawa@honoluluadvertiser.com.