Erosion in Waikiki has been a long-time concern and the City and County of Honolulu is once again looking for solutions to combat the problem.
On Sunday, Mayor Kirk Caldwell announced a new pilot project at Kuhio Beach.
City officials installed what’s called a ‘sand mattress’ there on Tuesday.
We’re told it uses technology that works with Mother Nature, rather than against it.
Inside the mattress are several tubes filled with sand and then more sand was placed on top.
The mattress is made up of a special material that traps the sand inside and prevents the water from washing it back out into the ocean.
“It gives it a lot of mass so when the wave energy impacts the wall, the wave will wash up the beach, and then it will protect the soil from eroding underneath the mattress. But because of its weight, it stays in place,” Troy Ogasawara, President of Geotech Solutions, said.
Officials told KHON2 the cost of this pilot project is about $3,000 and the sand mattress is estimated to last 10-20 years.
“This technology originally came from Asia where its used for embankment stabilization, shoreline stabilization, and large river embankment stabilization projects,” Ogasawara said.
It’s the latest attempt to stabilize the beach and make it safer for visitors.
Previous projects, like moving sand, ended up not working and eventually posed a risk.
“There were big chunks of concrete that were kind of loose and [a] tripping hazard,” Dolan Eversole, Waikiki Beach Management Coordinator with the University of Hawaii Sea Grant Program, said.
“The coconut trees were at risk of erosion and falling over over time if that dirt kept eroding from that sand,” Office of Climate Change, Sustainability and Resiliency Executive Director Joshua Stanbro said.
We’re told the sand mattress has proven to be effective in other parts of the world, but there is still some skepticism.
“It just broke it and crumpled it up and I’m thinking if it can do that to concrete, what chance does the blanket have? There’s always been these temporary Band-Aid fixes down here,” Corbin Peleiholani, a surf instructor, said.
KHON2 asked about ideas for long-term solutions.
“We’re working with the Department of Land and Natural Resources on putting in a sandbag groin,” Rick Egged, President of the Waikiki Beach Special Improvement District Association, said. “Now these are not the normal small sandbags. These are sand bags that weigh a ton and the idea is that you use them to create this groin.”
The goal is to get that larger sand bag groin installed and completed by 2018, but we’re also told more sources for sand need to be identified.
The city says Kauai County and Hawaii County have also looked into the sand mattress for their erosion problems.