Rains highlight chronic flooding at Mapunapuna

By James Gonser
Advertiser Urban Honolulu Writer

Connie Smales, co-owner of Plywood Hawai'i on Kikowaena Place in Mapunapuna, estimates the damage to her business after flooding Sunday to be at least $70,000.

About 60 pallets of plywood were destroyed at the business, which backs onto Moanalua Stream, and two were even picked up and carried away by the water. Employees arrived at work Monday to find plywood floating in two feet of water in the warehouse. Outside was five inches of mud in the parking lot, Smales said.

Flooding has been a problem in this low-lying area for decades. The ocean backs onto the streets at high tide, while sinking soil has put some areas below sea level.

"I think it is time we got together with the governor and the mayor and they can tell us what they are going to do about it," said Smales. "We are not sure whose responsibility it is, but people have got to stop pointing fingers and start doing something about it."

As owner of the streets, the city is responsible for maintaining the stream and drainage, said Tim Steinberger, director of the city Department of Design and Construction.

The city and former landowner Damon Estate are studying solutions, but the focus of the study is more on the effects of the tides than stream flooding, and any solutions appear to be expensive and years off.

Some parts of O'ahu got hit by as much as 11 inches of rain in a 24-hour period on Sunday, causing road closures and overflowing steams. Moanalua Stream topped its banks near Moanalua Gardens and spilled onto Moanalua Freeway. In Mapunapuna, the situation was aggravated by the high tide, which blocked all drainage and forced the stream over its banks.

The industrial area developed in the 1940s by Damon Estate is almost entirely inside a special flood hazard area. The businesses are built on fill and are sinking.

Damon Estate sold the property last week to Newton, Mass.-based HRPT Properties Trust.

Tim Johns, Damon Estate chief operating officer, said the estate and the city are splitting the $100,000 bill for the flood study that looks primarily into the problem of streets being flooded at high tides.

The study is being conducted in three phases: a historic review of documents; field investigations, including land, water-level monitoring and surveying, currently under way; and recommendations to control flooding, due to be completed next summer.

Johns said the estate no longer owns the property, but is still concerned about the success of long-term tenants.

"We are not their landlords anymore, but obviously we are concerned about how anybody gets impacted by a natural disaster of this sort," Johns said.

Steinberger said the study also would take into account this weekend's flooding, an event that occurs only about once a decade, he said.

"This has been occurring since the '40s, when that area was first built," he said. "It is not a new situation that anyone should be surprised about."

Smales said the city cleaned the stream of most mangrove a few years ago, but never dredged the area. She thinks that might prevent flooding.

But Steinberger said the high tide combined with too much rain left nowhere for the water to go, so dredging would not have helped.

"The water level in the stream was higher than the elevation of the drains," he said. "There was such a large amount of water coming down the system, it couldn't handle it."

The city will be looking for cooperation from the property owner to foot the bill for solutions recommended by the flood study, Steinberger said.

Reach James Gonser at jgonser@honoluluadvertiser.com or 535-2431.