With nearly a week having passed since two car-sized boulders rolled down the hillside in Waimea Bay on Oʻahu, crews have been assessing the rockslide and estimating the cost of minimizing future risks.
According to Hawaiʻi Department of Transportation Director Ed Sniffen, it may cost upwards of $20 million dollars to minimize falling rock hazards to motorists traveling on Kamehameha Highway.
After spending a week out in the field, Sniffen joined HPR to talk more about the rockfall and reducing risk in the future.
“We made sure we shut down the roadway as quickly as possible to make sure nobody else was put at risk. Cleared the slopes of all the loose boulders that we found up there, another 16 or so,” Sniffen said.
He explained that the boulders were likely loosened by the heavy rains, and the risk remains for further rockfall to occur.
“Once one comes down, there's a bunch of nested boulders in those areas that are all destabilized,” he said. “So we expect to see more boulders that we're going to have to take down.”
“We’re extremely lucky that nobody died,” Sniffen emphasized. “What the public should also understand is we have to do this project, regardless of whether we do it now or do it in the future.”
By treating the rockfall as an emergency, risk minimization and road repair efforts are already underway, with Sniffen estimating four months to complete the project.
This story aired on The Conversation on April 16, 2026. The Conversation airs weekdays at 11 a.m. Jinwook Lee adapted this story for the web.
