Army Corps of Engineers, city try again on Ala Wai flood control — this time with more modest goals

HONOLULU (HawaiiNewsNow) - Officials have gone back to the drawing board on efforts to protect residents and others from flooding in the Ala Wai watershed, which includes the tourism center of Waikiki.

The project was originally intended to protect the area from a once-in-a-century flood, funneling rainfall from major storms into the ocean so that it doesn’t flood the tourist hub.

“The fact that we were designing for a storm that had never been experienced in the community is probably the definition of over-engineering,” said Lt. Col. Eric Marshall, the Honolulu commander for the U.S. Army Corps of Engineers.

“Now I’m not saying that we did anything wrong. We were doing what we were authorized to do,” he added.

The original scope included large retention basins to hold back floodwaters in Manoa and Palolo along with 4-foot-high walls along the banks of the Ala Wai Canal.

“The community was very much against those types of invasive structures,” said Marshall. “Not only was the community against it, frankly, they’re expensive.”

The estimate came in at $651 million, well above the original $345 million budget.

“Now, we’re not asking ‘in the event of said named storm back in 2006,’ we’re now saying ‘any time,’” said Marshall, in explaining the new aim of the project.

The corps and the city have started a series of town hall meetings — online for now — to get public input on what should be done. That has brought residents forward with their concerns, including blockages upstream that have resulted in more damage during storms.

“I think it’s a maintenance thing, and that goes back to the city, right?” Manoa area resident Ellen Watson told the corps in the first meeting. “So the city’s not able to maintain the streams, clearly.”

In response to those concerns, Honolulu Mayor Rick Blangiardi said, “We have a real concern on our hands, and we’re trying to deal with, quite honestly, some long overdue maintenance. I don’t know how else to say it. And that makes this project even more critical to me.”

The city is also looking at the effects of climate change, including the possibility of stronger storms, along with coastal flooding from higher ocean levels.

“We’ve had flooding with the king tides,” said community member Daisy Murai. “We’ve already seen some water that overflowed from the Ala Wai Canal not too long ago, so all these things are happening now.”

The corps said some structures may be needed, but it’s also looking at using vegetation to slow water down, along with other nature-based measures.

“We’re allowed to design for something that is very practical, and I hope very desired by the community,” said Marshall.

There are still several more rounds of public input scheduled, with a final report expected two years from now. That’s also the soonest that the federal government will decide whether or not to fund it.

Copyright 2021 Hawaii News Now. All rights reserved.