KAPA‘A — The Kaua‘i Planning Commission approved last week the rebuilding of a rock seawall in Kapa‘a that is currently threatening the safety of private property, pedestrians and beach-goers. Hurricane ‘Iniki ravaged Kaua‘i on Sept. 11, 1992, bringing wind gusts
KAPA‘A — The Kaua‘i Planning Commission approved last week the rebuilding of a rock seawall in Kapa‘a that is currently threatening the safety of private property, pedestrians and beach-goers.
Hurricane ‘Iniki ravaged Kaua‘i on Sept. 11, 1992, bringing wind gusts of over 200 mph and surf heights of over 20 feet.
The rock seawall fronting Pono Kai Resort here was extensively damaged, but it was rebuilt a year after ‘Iniki.
Now, 17 years later, the 600-foot-long seawall is again damaged and collapsing.
The Kapa‘a multi-use path sits a few feet from the seawall. Sand washing through the rocks may cause instability and result in sink holes nearby, said a report from Oceanit, a consultant firm hired by the county.
County Department of Public Works Building Division Chief Doug Haigh, who is also the project manager, said construction will take about two months, during which the adjacent portion of the 12-foot-wide Kapa‘a multi-use path will be closed or possibly re-routed.
The existing wall is deteriorating on both ends, Haigh said. “We’re trying to build a wall that is designed properly so it won’t do that.”
The new wall will be about 150 feet longer than the existing one. Sheet pile will be driven or vibrated about three feet below sea level into the ground. The base of the new wall will be excavated and the rocks from the old wall will be brought back to reinforce the toe of the sheet pile, Haigh said.
Sheet pile is made out of vinyl or steel, and shaped as the letter w. Haigh said the county hasn’t decided yet which material to use.
The new seawall is supposed to create a larger beach, since the project’s design retreats the seawall to only five feet from the bike path and, at one point, it’ll be right up to the path, said Haigh.
Naupaka, a native plant species, will be planted by the wall to prevent people from walking off the edge.
Haigh said the goal is to utilize the sand that has been dredged from the nearby Waika‘ea Canal, and bring it back to the beach.
“Our challenge is to coordinate with the (state) Department of Health,” Haigh said. “If we don’t, our plan is to put that sand above the high tide.”
Haigh said that shortly after the state had dredged the canal, the sand came back.
“Clearly the jetties that were built by the state are interfering with the flow of sand along the coastline,” Haigh said.
When the state dredged the canal, the county provided them access to the beach park. Haigh said the county was told they could use the dredged sand and place it alongside the eroding beach on the other side of the jetty.
The state Department of Health Clean Water Branch, however, was afraid of the turbidity that would be introduced if the county put the sand along the shoreline, a sand that was already there in the first place. So the county was barred from putting the sand on the beach.
“Logic works for us,” said Haigh.
State vs. state
Oceanit engineer Warren Booker said the dredging of the canal was done under a U.S. Army Corps of Engineers nationwide permit.
“One of the conditions of a nationwide shoreline is that you cannot put the sand back on the shoreline. It has to be disposed of inland,” he said.
From the state Department of Land and Natural Resources’ viewpoint, however, anything that comes from a dredging project that directly affects the beach should go back on the beach, Booker said. “These two agencies don’t agree with each other.”
“We got caught between the two state agencies, and we couldn’t put the sand in,” Haigh said. “So that’s why in this project we’re going to do our best to get through the hoops and get the approval from all the state agencies.”
Booker said there’s a possibility to apply for a small-scale, beach-nourishment permit, which is a combined state and federal permit, and then put the sand back on the beach.
Where’s the sand?
The sand that was dredged from the Waika‘ea Canal is being held by the county. Haigh said it has been analyzed to see if it matches the granular size, and it’s ready to go back on the beach.
“Hopefully it’ll still be there when we’re ready for it,” said Haigh, apparently joking. But Planning Director Ian Costa said immediately after that “sand does tend to disappear.”
Costa said there’s funding available for a study on the coastal movement of the sand.
The person who was managing the project, however, retired last month, and the project hasn’t been reassigned yet, according to Haigh.
The rock-seawall project has funding secured, and the county is only waiting to obtain the permits from DOH and the Corps of Engineers. Haigh said the project should start anytime between this fall and the beginning of next year.
• Léo Azambuja, staff writer, can be reached at 245-3681 (ext. 252) or lazambuja@kauaipubco.com.
