A decision by Hawaii County’s mayor to close the popular Waipio Valley Road is stirring debate on the Big Island, with some residents saying the decision caught them off guard and others calling it heavy handed.

Citing threats to public safety from hazardous road conditions, Mayor Mitch Roth issued an emergency proclamation on Feb. 25 that bars access to the road with few exceptions — possibly until 2025.

“Waipio Valley Road is in imminent threat of slope and roadway failure threatening the health, safety and welfare of the people,” according to the emergency order. The danger is of such magnitude that it warrants “preemptive and protective action.”

On Friday, the mayor’s spokesman said despite some of the criticism over the road closure, Roth stands by the decision.

“We understand that this decision has caused frustration for certain members of our community but are confident that the effort will only create a safer environment for all of the valley’s visitors moving forward,” said spokesman Cyrus Johnasen.

Waipio Valley Road is a steep, narrow corridor on the Big Island’s north shore that drops dramatically to a mile-long, black sand beach across the valley floor, as well as the Muliwai Trail and campground, and the mauka-to-makai King’s Trail.

The emergency closure allows road access to continue for valley residents and farmers, property owners and leaseholders engaged in agriculture or animal husbandry, and government employees, contractors and others responding to an emergency.

The order doesn’t say how long the road will be closed but a Department of Public Works spokeswoman said it could last up to three years. The total cost of the project isn’t known yet but the county has the funds, said spokeswoman Sherise Kanae-Kane.

Engineers will develop a mitigation plan over the next four to six months and develop cost estimates for corrective measures, said Steve Pause, the department’s deputy director, in a recent community meeting.

Ed Johnston, a retired horticulturist who lives in Pepeekeo north of Hilo, said news of the road closure left him surprised and dismayed. He’s concerned about the loss of access to one of the island’s most stunning locations. Waipio is one of the few places left in the Hamakua District where the public can legally access the ocean, Johnston said.

Johnston is equally baffled by why the mayor’s office would take such drastic action based on the findings of a newly released geotechnical report the county commissioned to evaluate the Waipio Valley Road’s natural hazards.

The report, released in January, found the road is prone to landslides because of steep terrain and unstable soils, especially in the upper sections. At least three rockfalls happen every year on the road that require some level of county response. Rocks tend to cascade to the road when powerful storms slam the region. The report found the chance of a pedestrian getting killed by a rock was about 1 in 18,000. The estimated loss of life for someone in a vehicle is calculated at 1 in 170,000.

Johnston doesn’t think those statistics, even if proven accurate, should warrant closing such an important road to the public.

“It doesn’t make any sense,” said Johnston, adding he thinks the risk analysis warrants scrutiny.

Many Hawaii trails feature similar hazards, but they remain open for public use, he said.

Ninole resident Chris Yuen, a state land board member and former Hawaii County planning director and deputy corporation counsel, also questioned the findings in the report on which the mayor’s decision was based.

Speaking as a private citizen and not in any official capacity, Yuen said he emailed county officials to explain why he firmly believes that the rockfall risk assessment drastically over-estimated the risk. He said if its numbers were correct, you would expect 2.8 pedestrians killed per year by rockfalls.

“That cannot be right,” he said. “The mere fact that no one has heard of a pedestrian being killed demonstrates that.”

Waimea resident Ariel Clark questioned the mayor’s decision as well.

“My risk of dying of heart disease is one in seven,” said Clark, a surfer who grew up on the Hamakua coast.

That doesn’t mean she’s going to sit around and wait for a heart attack. Life goes on and you learn to manage risk, in her view.

Clark said she wonders if the county is using the geotechnical report as an excuse to close the road permanently because of pressure from Waipio Valley users who want to see fewer pedestrians and vehicles on the road.

“This has been boiling for years,” Clark said. “The road closure seems to be a quick and easy fix.”

After the mayor announced the road closure, the Island of Hawaii Visitors Bureau expressed its full support. The bureau has not promoted tourism in the Waipio Valley for more than a decade because of concerns about the impacts on what is a “sacred and culturally significant place,” said Ross Birch, executive director.

A Hawaii island destination management plan identifies Waipio Valley as a “hot spot,” or place attractive to visitors but one that’s associated with overcrowding, congestion, safety hazards and other negative experiences.

The bureau is letting visitors and the tourism industry know about the road closure “both here on-island and across the globe,” Birch said.

Kanae-Kane said the road closure has nothing to do with tourism impacts at Waipio Valley. The geotechnical report found that current conditions present a risk of injury or loss of life that exceeds established thresholds. Traveling on the road is a serious safety risk that needs to be  addressed, Kanae-Kane said.

At the same time, Waipio Valley is a wahi pana, or celebrated place, and deserves to be treated as such, according to Johnasen, the mayor’s spokesman. The road closure is not permanent but it “offers a time for the aina to mend — as well as the road,” he said.

The county will hold a virtual public meeting about the road project from 5:30 to 7 p.m. Wednesday.