HONOLULU (HawaiiNewsNow) - In 2025, the state's largest public works project will officially be complete: A 20-mile rail line with 21 stations and a price tag of $8.2 billion.
But the biggest threat facing Oahu's rail project may not be whether people ride it, but how it will survive what environmentalists and planners agree will be one of the most destructive and costliest disasters to face the islands: Sea level rise.
In a little over 30 years, a portion of Oahu's elevated rail system that will run through Honolulu's urban core could be submerged in floodwaters if sea levels rise by as much as 3 feet as projected, rail officials acknowledge. Under this scenario, and barring mitigation efforts, the support columns holding up the rail guideway would be under water and the station entryways could be inaccessible.
"If sea level rise happens within that timeframe, or some other impact, we've got to be ready to do something about it, at least at street level," said Leo Asuncion, director of the state Office of Planning and co-chair of the Hawaii Climate Change Mitigation and Adaptation Commission.
According to the group, everything from Hawaii's most popular tourist destination — Waikiki Beach — to its busiest airport is under threat.
Sea level rise of 3 feet by mid-century and beyond, according to a comprehensive report the commission submitted to the state Legislature, will mean widespread destruction to Hawaii's critical infrastructure, with more than 6,500 structures near the shoreline being compromised or lost, 25,800 acres of land flooded, and chronic flooding of major roads, utilities and other key structures.
As Hawaii is at the front lines of this unprecedented event, the commission says, it's clear that something must be done to save the state's major infrastructure projects that are critical to the state's economy. But what's unclear is what exactly can be done — and what we should be doing right now.
No project underscores that uncertainty better than Honolulu's rail line.
Is rail ready for rising seas?
With part of the rail's route weaving through the downtown Honolulu area — and in and along potential inundation zones — sea level rise will affect rail in some way, rail developers and environmentalists agree. What's not clear yet is how.
But the biggest impact will undoubtedly be to ground level rail stations, at least eight of which officials with the Honolulu Authority for Rapid Transportation have acknowledged are at risk of flooding by 2050 under current sea level rise inundation models.
HART said it's well aware of the problems it faces with the impending hazards of sea level rise, but because there's so much uncertainty when it comes to the exact impacts, the mantra rail officials have right now is this: Build the rail now and make adjustments later.
"We are building for today and that's the thing we should be doing, for today and for the near future," said Bill Brennan, communications director for HART. "If we need to adjust down the line, there's going to be much more involved than just the rail station."
Asuncion, of the planning department, said the rail line faces the biggest sea level rise threats in the urban core.
"The issue of sea level rise and inundation really comes down to when you exit a station and whether or not you can get around, assuming it's at street level," he said. "Can you still get around if that place is inundated or subject to sea level rise?"
In 2015, HART conducted a study that determined that flooding might reach the floors of some of the station entries. HART said those particular stations don't have contracts yet – and that they might not be awarded until 2020.
The five-page analysis, which assessed the potential of sea level rise at each vulnerable station, gave an estimate of how much the floors would need to be raised to avert possible flood damage in the worst-case scenario. Levels range from less than a foot to nearly 3 feet.
But the general consensus of the 2015 study: HART is not obligated to take any action but will leave it up to design firms to investigate the impact on ground-level entries, then submit their findings to HART for review.
After this story was originally published, Brennan said in an email, "We'll design for tomorrow by having our future contractors investigate the potential impacts of sea level rise on the floors of the station entries that could be impacted."
Another big obstacle HART faces: Flooding will hit other government and private infrastructure before or at the same time as the rail.
For example, if flooding happens in downtown Honolulu, it will likely impact Aloha Tower and Hawaii Pacific University first before creeping toward Nimitz Highway and then the rail station. That means all those separate entities, Brennan said, will be dealing with it before the city can do anything.
"That same sea level rise that would impact the downtown station would also impact Nimitz Highway, so either knowing that it's coming, whatever adjustments DOT makes ahead of time to avoid or prevent impacts from sea level rise would dictate now that they've done X, we have to do Y," Brennan said. "We'd probably have to coordinate with the state DOT."
Daniele Spirandelli, assistant professor for the University of Hawaii's Department of Urban and Regional Planning and Sea Grant College, said what makes it even tougher for these entities to plan ahead is that, as researchers are still gathering the latest data on climate change, everyone is still waiting for more guidance on policy changes that could offer greater clarity on how to handle infrastructure threats.
"If you think about infrastructure, it's all interrelated, so it would make sense for there to be a coordinated vision effort across the city and county, and that also is aligned with the state," Spirandelli said. "I imagine that a lot of these agency heads are looking to see how other agencies will be responding and reacting."
'Here is climate change'
The state has already been seeing the effects of climate change, researchers say, with several rounds of record-breaking high tides, also known as "king tides," swallowing up stretches of Hawaii beaches late last year. And just in the last few months, severe erosion has claimed the foundations of homes on Oahu's North Shore and eaten away at the grounds of a cemetery in Paia.
Asuncion said while most planners and scientists know what they're dealing with as far as the impacts of climate change, what's unclear is how they should respond — seek to move infrastructure away from the shoreline, construct sea walls to slow rising water levels, or allow land in inundation zones to flood.
"I think really people need to absorb everything first, kind of take a breather, step back or whatever it is and go, 'Here is climate change,' and really, what do we need to tackle first?" he said. "It's a challenge, but I think people need to start looking at it like an opportunity."
While Spriandelli agreed that it is difficult to know what exactly should be done ahead of time, she also said waiting too long to act could end up being very costly for the islands.
"What's been shown in many other places is that the longer we take with making those kinds of decisions is that it will most likely cost more later on down the line," Spirandelli said.
She added that the rail project is clearly a huge investment and that officials should be having conversations now about how they'll pay for the impacts of climate change by mid-century.
The cost of sea level rise? In the billions
According to the state climate change commission's report, sea level rise will result in an economic loss of more than $19 billion across the state, and that does not account for damage to roads, utilities — or the rail project.
Although HART believes that it can construct the entire rail system with its $8.2 billion budget by 2025, the question remains: Where will the money come from if flooding takes a toll on rail?
That question would fall on the city's Department of Transportation Services, Brennan said, which would have jurisdiction over the rail line and stations once they're built.
"All the operation and maintenance budget will be decided on a yearly basis by the city, so whatever it is that's needed for rail operations will be part of the budget," Brennan said.
And obtaining federal funding for climate change mitigation or relief projects seems out of the question — for now.
With a sudden disaster like a hurricane or tsunami, certain infrastructure projects could get federal assistance through the Stafford Act, like the billions of dollars in aid that Texas received after Hurricane Harvey devastated parts of the state in August 2017.
But Makena Coffman, chair of the UH Department of Urban and Regional Planning, who was also appointed to the city's climate change commission, said we're heading into uncharted waters with what's been dubbed a "slow-moving disaster."
"Even though you could be having frequent erosion events that are quite disastrous, they don't trigger the same kind of policy mechanisms, and so that makes them very different from the perspective of how do we as a state think about solutions," Coffman said. "How do we finance it?"
Hawaii looks within for climate change guidance
Spirandelli added that there's also no leadership coming from the federal government — and even more so after President Donald Trump withdrew from the Paris climate agreement last year — but that there could be hope on a micro level with Hawaii seemingly stepping up efforts to curb climate change through the creation of commissions both at the city and state level.
HART also believes it's already looking ahead by building an elevated system to avoid problems in the event of flooding — whether it's climate change-related or a more sudden disaster — and by constructing foundations for columns strong enough to withstand any kind of water event.
Brennan said the elevated rail system could prove invaluable, for example, "in emergencies or in case of sudden storm surge or something where people can move from one point to another on an elevated guideway that's not impacted by the same condition that would impact cars, trucks, buses and everything else that's on ground level."