New landslide risk found at Castle Junction

By Mike Gordon
Advertiser Staff Writer

State transportation officials say it will be three weeks before they can re-open a busy righthand-turn lane at Castle Junction while they seek a temporary solution to landslides in the area.

Kailua drivers going uphill toward the Pali will find the turnoff from Kalaniana'ole onto Kamehameha Highway closed. But adjusted intersection lights will safeguard a sharp right turn toward Kane'ohe. Richard Ambo • The Honolulu Advertiser

But they have no idea how to stabilize the crumbling bluff where rocks and other debris have fallen four times in two weeks, said Scott Ishikawa, spokesman for the Department of Transportation.

The department was forced to scrap its initial solution after the discovery yesterday of huge cracks along the top of the 30-foot-high bluff, Ishikawa said.

"The scope of the project just got bigger," he said, standing at the base of the pale-orange bluff. "It's all or nothing now. If we go halfway, it won't work."

The righthand-turn lane follows the curve of a bluff that a recent study ranked fifth on a list of O'ahu's 66 most hazardous highway landslide areas.

The study, done by the Honolulu firm Earth Tech, noted that high, steep slopes of volcanic rock above the highway are highly deteriorated and there is no rockfall catchment in the area, where traffic is heavy.

Officials shut down the merge lane Monday after 30 cubic yards of soil and rocks fell on the road about 4 a.m. They thought they could reopen the lane but rejected the idea after rocks — some as big as softballs — fell from another area of the cliffs about 2 p.m., Ishikawa said.

Debris from the cliffs also came down May 20 and May 23. As Ishikawa outlined the state's plans yesterday, rocks and tiny rivers of dirt slid down the bluff.

Officials are worried because the landslides have come down during dry conditions. "If we have rain, the weight of the whole slope might bring it all down," Ishikawa said.

Before officials discovered the cracks, some nearly 4 inches wide, the state had planned to carve away the loose soil, Ishikawa said. A consultant will need to be hired to assess the problem, but the department is not sure how long that will take. Solving the problem could cost $6 million, according to "a very preliminary estimate" in the Earth Tech study, Ishikawa said.

Ownership of the land is also unclear, and no work will begin until that is verified. The land may belong to nearby Hawai'i Pacific University.

Meanwhile, drivers heading for Kamehameha Highway are able to make a sharp right turn off Kalaniana'ole at the intersection. Traffic lights have been adjusted to help the flow.

But rush-hour traffic still backs up to the site of the old Kailua Drive-In.

Some drivers ignored the safety cones Monday afternoon and used the merge lane, Ishikawa said. Barriers have been set up to prevent that.

"It was kind of frustrating," Ishikawa said. "We are trying to seal off an area we feel is hazardous. We're asking people to be patient."

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