RICHARD WALKER / RWALKER@STARBULLETIN.COM First Lt. Carl Hood of the Hawaii Army National Guard peered yesterday into a large sinkhole that had formed on the bank of the Kailua Reservoir in Waimanalo. CLICK FOR LARGE

Clearing of Kailua Reservoir begins

The structure is being broken down after a sinkhole weakened it

Turning a reservoir into a stream is hard work.

Equipped with chain saws, machetes and axes, more than a dozen members of the Hawaii Army National Guard started clearing debris yesterday on a portion of the crest of the Kailua Reservoir in Waimanalo.

"We're just scratching the surface," said 1st Lt. Carl Hood, of the Hawaii National Guard.

They are expected to return today to remove more debris as part of the state's preliminary work to break down the reservoir and turn it into a stream.

"There's a bunch of work that needs to be done," said state Adjutant Gen. Robert Lee, who said earlier that the reservoir is "not sound."

State officials were not certain the reservoir would hold in another period of heavy rain. April 2's heavy downpours created a large sinkhole, the result of a crack in the outflow drain, that lessened the strength of the reservoir's wall.

More than 30 families were evacuated from their homes that day after water in the dam threatened to overflow.

Yesterday, National Guard members removed large amounts of brush and cut off tree branches near a concrete spillway. They also cut down a 60-foot tree that caved into the 30- to 35-foot-deep sinkhole.

The sinkhole is causing some problems. "There's a concern with the stability of the hole," said Brian Kau, administrator of the Agricultural Resource Management Division.

The Kailua Reservoir is about 2 to 2.5 acres with the capacity to hold 4 million to 5 million gallons of water.

The dam was reportedly built in the 1930s for irrigation. The state shut down the reservoir in 1993.

Officials said the reservoir was not built for flood control.

But Kim Kalama, whose property abuts the reservoir, said it has helped prevent flooding. The dam helps control the outflow of water, Kalama said.

RICHARD WALKER / RWALKER@STARBULLETIN.COM Soldiers from the Army National Guard removed overgrown brush and debris yesterday from the area around the spillway of the Kailua Reservoir in Waimanalo.

They said they asked the state to replace the outflow drain located near their property, which they described as the main drain for the reservoir, more than 10 years ago.

Had the drains been functioning properly, there would be no problem with the reservoir, Kim Kalama said.

David Kalama, who has lived on his property for about 50 years, also said he and his wife are worried about residents who live downstream being affected when the dam is broken down.

Lee said they are working with the U.S. Army Corps of Engineers to assess the area downstream of the reservoir.

"I certainly don't want to move the problem from up there to down there," he said.

Sandra Lee Kunimoto, chairwoman of the Hawaii Board of Agriculture, is seeking $2.5 million from the Legislature to cover the cost of the work at Kailua Reservoir.

Kunimoto has said there are no long-term plans for the reservoir. The state completed an environmental assessment on a plan to remove the dam six years ago. The state backed off the plan and did more studies after residents objected.

The Army Corps of Engineers, the state Department of Land and Natural Resources, and the Natural Resources Conservation Service have been working with the Department of Agriculture on what to do with the reservoir.

The Natural Resources Conservation Service is also being asked to plan and conduct any downstream changes in conjunction with the work on the reservoir.