Homeowner uses tubes, mats to shield property

More than 20 years ago, a friend asked Joe Correa, a plumber and general contractor on Oahu, to help him with a beach erosion problem.

Correa did, and got fined for building a sea wall without a permit.

He's now come full circle, becoming (probably) the first contractor in the state to remove a sea wall without replacing it with another one. And he's a prophet for a new approach to dealing with eroding beaches.

Instead of piling up rocks, he advocates a "soft" approach. "That's the right way to go," he says now.

Beaches advance and retreat in natural cycles, and even beaches that experience episodes of deep erosion frequently see that only a few days out of the year.

Correa is working to get the Department of Health and other agencies to accept a new technique of dealing with storm-washed dunes: Put down a coconut fiber mat to absorb the shock, then take it away.

Meanwhile, and after lengthy permitting reviews, he has gotten permission to use his coir mats and tubes on a few projects, including one in Kihei that was finished last week.

Hardened or armored coastlines can take several forms: rocks, poured concrete, steel pilings or sand-filled geotubes.

The geotube is advocated by some as a softer way, because unlike a concrete wall, it can be removed or shifted by emptying it of sand. Correa, however, doesn't like it.

The tubes last a long time but not forever. "The polyester leaves a residue. Turtles eat it and develop tumors. Fish eat it. We eat the fish, and we develop tumors. We have to protect us human beings," Correa said.

His coir tubes look and initially function like a geotube. The difference is that they are porous and biodegradable.

Native or indigenous plants, akiaki grass and pohuehue (beach morning glory), can be planted in the pukas, and the hope is that by the time the coir rots away, the plant roots will have established themselves in the dune to stabilize it.

The approach costs "about 50 percent" more than harder protections because of high initial costs and continuing maintenance, Correa said.

A rock wall is "set it and forget it," but the coir mats and tubes need some attention, plus the Clean Water Branch requires monitoring, since "you're putting something in the water," he said.

Correa gets his coir from Sri Lanka. It comes in 1- or 2-meter-wide mats or 54-inch tubes with a 12-inch diameter. The mats have "wattles" that help catch sand.

The tubes weigh 880 pounds when filled with sand, which means using construction equipment to get them into place.

Correa also uses a kind of stiff netting that "looks like a link sausage." This comes in 10-foot lengths of 6, 8 or 12 inches diameter. "It works real nice. It acts as a filter around a storm drain."

Coir matting "is expensive, but in the long run it's not expensive," he said, because it's the better method.

He still uses geotubes sometimes. Recently on Kauai he had a contract with the county to use geotubes as temporary protection where a road was washing away.

The geotubes replaced rocks the county had dropped down as an emergency measure.

When you use soft methods, it requires "keeping an eye on the ocean, but that's the way it should be," Correa said. "We should be more conscientious of our interference" with natural systems.

* Harry Eagar can be reached at heagar@mauinews.com.