‘Lava bridge’ idea gains support

PAHOA — Could the June 27 lava flow be bridged?

PAHOA — Could the June 27 lava flow be bridged?

With the flow again closing in on Highway 130 — the only permanent route in and out of lower Puna — county and state officials say they are continuing to assess the possibility of creating a road over the flow to maintain access to the region.

And it might be as simple as piling cinder on top of the flow’s outer crust. Lots of it, anyway.

“Our concept, at the county, is put down big rocks, then little rocks, compact it, make it smooth and driveable over it,” said Warren Lee, Hawaii County Public Works director.

The state Department of Transportation, which is responsible for the highway, is taking the lead on testing that solution and others like it. Piles of crushed rock of different sizes have been placed on top of the cooling lava flow on Apa‘a Street to see how well they displace heat.

So far, no conclusions have been reached.

“We’re going to test it as long as possible,” said Derek Inoshita, DOT spokesman.

“They need to know if the material will stand up to the heat over the long term.”

Inoshita said data will be collected until the highway is inundated. Then, it could be a matter of waiting for the flow to crust over enough to give it a shot.

But officials also might wait until lava reaches alternate routes farther downslope.

“They will want to wait to make sure all the alternate routes are exhausted before they went ahead with this,” Inoshita said.

Lee said it’s possible a road could be built with an active tube still in place as long as it was “way below the surface.”

“When is it going to be safe, and what is safe?” Lee said are questions that still need to be answered.

“I think every lava flow is different,” he said. “Once we get the data from DOT, we can make a better projection.”

One Pahoa man already put theory into practice.

A few hundred yards mauka of Pahoa Village Road, a dirt road has been cut into the inactive lobe of the lava flow.

The road is about 90 yards long and sits on the property of Melvin Sugimoto, whose orchard was partially buried when the flow entered his property in late October.

He declined to be interviewed for this story, but his friend, Bryson Kuwahara, said Sugimoto built the road three weeks after the flow stalled and began to cool. He said he needed it to access cacao trees spared by the flow.

His bulldozer easily cut into the flow’s hardened crust and didn’t contact any residual lava, Kuwahara said, even though it was oozing molten rock less than a month before.

The road might not have been entirely on solid ground. Toward the center, the surfaced remained warm to the touch a week ago, indicating the presence of stagnant lava not far below.

Otherwise, it looked as safe as any dirt road on the Big Island and, in the process, made the flow seem much less menacing.

Kuwahara, owner of Bryson’s Cinders in Pahoa, said it shows that re-establishing road access, ideally over the highway, can be done even with the presence of lava underneath.

“I sure rather go this road than Chain of Craters Road,” he said.

That route, being re-established from Kalapana into Hawaii Volcanoes National Park, would be used as a last resort should the flow cover other alternate routes downslope. Like the other emergency access routes, it, too, would have a gravel surface.

“Keeping Highway 130 is what will keep the town alive,” said Brady Metcalf, owner of Pahoa Auto Parts.

“If you try to put every car through there (Chain of Craters Road), if that’s all that’s left, it’s going to be a mess.”

Kuwahara has his own idea for making the highway passable, should lava cross it.

In addition to cinder, he said 40-foot-long metal “flat racks” used by Matson as a deck for shipping cargo could be placed over areas where there is still a lava tube underneath.

In case the tube collapses, the decks would be long enough to bridge the gap, Kuwahara said.

That idea, and others similar to it, appear to be catching on around Pahoa.

Russell Ruderman, lower Puna’s state senator and owner of Island Naturals, which has a store in Pahoa, said it’s an example of Puna’s ingenuity.

“It’s a creative out-of-the-box idea that came from Puna for Puna,” he said.

“It’s not the end of the world for us,” Ruderman said.

Kuwahara said he doesn’t care if his idea gets used as long as a solution is found.

“At least we could try,” he said. “If there’s a better idea, no problem.”

Darryl Oliveira, Hawaii County Civil Defense administrator, said that idea has been passed along to county and state engineers working on a solution.

“There’s a lot of ingenuity out there, good ideas coming out of the community that might be viable,” he said.

Oliveira said the county is looking at every possible option.

“The goal is to have it accommodate the whole community,” he said.

“It might start as an emergency access route for resources coming in with a long-term plan for it to be used for the general public.”

No matter what solution is tried, it appears nothing like it has been done before. At least on this scale.

“We’re breaking new ground,” Lee said.

Email Tom Callis at tcallis@hawaiitribune-herald.com.