Friday, March 11, 2005

100 Manoa residents
hear state’s flood plan

More than 100 residents came out Wednesday night to hear the state's short-term flood mitigation proposals for Manoa Stream, which include installing a gauge warning system near Paradise Park and lining parts of the waterway with concrete.

Eric Hirano, chief engineer for the state Department of Land and Natural Resources, said all of the proposals are preliminary and haven't gotten any input from different governmental sectors.

Any mitigation project is also between two and 10 years away.

"This flooding event was very intense," Hirano told attendees. "Now, what can we do to prevent something like this again? What can we do with our limited funding to try to mitigate a (future) flooding event?"

The meeting at Manoa Gardens Senior Housing Complex was one of the first opportunities for residents to hear the state's proposals for preventing a repeat of last year's Halloween Eve flood, which caused millions of dollars in damage to Manoa, including the University of Hawaii's flagship campus.

Most of the attendees' homes had sustained damage in the flood, and some were disappointed that the state didn't have any planned projects that would soon be under way.

"I kind of knew it might take some time," for a solution, said Leighton Wong, a Manoa resident whose home escaped damage. "But 10 years is a long time."

Paul Mizui, civil branch chief for the U.S. Army Corps of Engineers, also presented the federal government's long-term plans for Manoa Stream. He said the waterway, which is a tributary of the Ala Wai Canal, has been included in the canal's long-term flood mitigation study. That could mean federal funds to lessen the chances of additional Manoa Stream flooding could come through, but that could be more than a decade away, he said.

Some residents, like Jim Arcate, said the state should be more concerned about maintenance of the stream, and what officials can do to prevent debris from piling up in the waterway.

Portions of the stream are owned by private landowners, while other parts are owned by the state and city. And Hirano did say the state is collaborating on a plan, which would involve residents, and federal, city and state government agencies, on the stream's maintenance.

Arcate, who was on a cruise in the Caribbean when the flood washed through Manoa, said private landowners should come together and hire a contractor to clean their portions of the stream. Arcate's home wasn't damaged in the flood.

Others were concerned about plans for a warning system.

Hirano said the stream warning system would likely be installed near Paradise Park at Waakaua Street Bridge. He also said the project would be costly, and would only give officials an extra 30 minutes to warn residents and possibly order an evacuation.

"A proposal ... to try to install a flood warning system that has to be really coupled with how and when the warning system would be triggered because you don't want to have too many false alarms," Hirano said. "If they're (the state) looking to fund a flood warning system, they're really going to have to look at how a system would work."

The state's other flood mitigation proposals include:

» Installing break-away fencing in several areas, including between Pamoa Road and University of Hawaii faculty housing and from Woodlawn Drive to East Manoa Road. Hirano said that during the October flood, a number of conventional fences acted as dams once they were clogged with debris. And when they were toppled over, floodwaters rushed certain areas all at once.

» Raise Woodlawn Drive by 2 to 3 feet for a couple of blocks to keep it from channeling water into properties.

» Construct a concrete-lined drainage ditch along the Diamond Head-side of Woodlawn Drive.

» Build concrete-lined channels from East Manoa Road bridge to the Manoa Hillside Estates subdivision.

» Install a flap valve in the concrete channel wall where a small drainage ditch in the southern end of Manoa District Park enters the concrete channel-way.

The Army Corps of Engineers will conduct a study next month, which is expected to be published in July, on the causes of the Manoa flood. Hirano said the study is expected to guide the state's next steps in looking for flood mitigation efforts.

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