On O`ahu, the industrial area of Mapunapuna, a former marsh that lies below sea level, floods whenever tides are high or rainfall is heavy. Two years ago, the City and County of Honolulu tried to fix the problem, spending nearly $1 million to install one-way valves in drainage systems. By December 2011, however, the floods were back (a faulty valve was blamed). Although the valves may stop seawater from entering the area today, they can do nothing to address inundation by brackish water from a rising water table in years to come.
The beaches of Ka`anapali draw hundreds of thousands of visitors a year to West Maui, but in the fall of 2003, management at the Maui Marriott hotel and the Ka`anapali Ali`i condos saw erosion on a scale that toppled trees and threatened walkways and a pool. The eroding face of the shoreline cliff was buttressed with 40,000 or more sandbags, and when those failed to halt the encroaching sea, the hotel brought in steel plates and Triton barriers. This year, the Ka`anapali Operations Association, made up of hotel and condo owners, sought to have the state match its own payment of up to $400,000 to pay for an environmental impact study in anticipation of a beach restoration project. Despite strong support from the Maui delegation, the Legislature did not approve the bill.
It is possible that climate change has nothing to do with any of these events. Even so, the challenges they pose are the very sort that will become more frequent and daunting in the not-too-distant future. Whether, how well, and how efficiently the state and county governments cope with these changes down the road will be determined, in large measure, by how they prepare for them today.
And if the measures taken at Anahola, Mapunapuna, Ka`anapali and Kapoho are any guide, the outlook is not great.
Plans and More Plans
One thing Hawai`i does have going for it, says Jesse Souki, director of the state Office of Planning, is the fact that no one in any meaningful position of responsibility is disputing that climate change is real. “One positive thing in Hawai`i that’s not often recognized,” he said in a phone interview, “is that we’re one of the few states where the conversation isn’t about whether it’s happening, it’s all about what we will do about it.”
In Virginia, the 2012 legislature refused to include the phrases “climate change” and “sea level rise” in a bill for a $50,000 study of climate change impacts on the state’s shorelines. As one legislator put it, those were “liberal code words.” Instead, legislators chose to describe the study as one investigating “recurrent flooding” and “coastal resiliency.”
With the blessing of Gov. Neil Abercrombie, Souki said, shortly after he was appointed to head the Office of Planning, “we began working on a climate change adaptation policy. I saw we had a policy dealing with greenhouse gases, but to be frank, if we produce zero greenhouse gases today, we’d still suffer for decades given what science is telling us – with sea level rise, a warming climate, the impact on agriculture and coastal structures,” and the like.
With the Office of Planning taking the lead, Souki convened about a group of around 60 people, representing federal and state agencies, some community groups, non-profits, and businesses (including insurers). With the help of Jim Dator, a futurist from the University of Hawai`i, “we were looking out 50 years or more, looking at future scenarios,” Souki said. Participants were asked to select a future and figure out how it could be achieved. “This served as a basis for climate change adaptation guidelines,” he said, which the Legislature passed in 2012 as Act 286.
“It’s a policy,” Souki said. “We’re the only state I know that has a policy passed by a legislative body and adopted by the governor. It’s integrated into the statewide planning act, so all land use decisions – decisions by the Land Use Commission, the Board of Land and Natural Resources, county zoning, all of that – need to take into consideration climate change adaptation.
“The actual things you need to do aren’t defined, and that’s where our office comes in. We’re not the only agency working on this, but we have made it a priority of the Office of Planning to assist sister agencies in the state and counties to deal with the impacts – how to integrate policy into action.”
The update of the Ocean Resources Management Plan is an important step forward, Souki said. “It’s an interagency document – the governor signed off on it, federal agency partners agreed to allow us to use their logos, which shows their support.”
“There’s a lot of science out there” that supports the policy, he said. “The issue is: how do we connect that to on-the-ground decision-making that is ongoing? How does science inform that?”
The Bathtub Model
One of those who is wrestling with those questions on a near daily basis is Sam Lemmo, administrator for the Office of Conservation and Coastal Lands within the state Department of Land and Natural Resources. The OCCL is the agency that regulates development and construction on state-owned submerged and coastal lands, up to the shoreline, and on all Conservation District land.
In a phone interview with Environment Hawai`i, Lemmo said that climate change impacts were now being considered whenever his agency processes Conservation District Use Applications for work in coastal areas.
But figuring out exactly how climate change should be modeled is complicated, he acknowledged. The National Oceanic and Atmospheric Administration has published sea-level rise maps for Hawai`i, he noted, but “it’s a bathtub-model approach. It’s two-dimensional. There are certain things you don’t see in that data.”
What Lemmo calls the “bathtub model” predicts coastal flooding based only on the sea level rising at a certain rate over a certain period of time and does not consider other factors that come into play, such as storm surges that reach far inland or low-lying lands flooded by higher water tables. “There are other potential models,” he said, “and we’re interested in looking for a higher resolution model for what sea-level rise will do to the Hawai`i shoreline.”
He acknowledged the plethora of studies already published that show the impacts of rising sea levels on the state’s shores. “It’s a lot of regurgitation of the same old thing, kind of like a broken record… They don’t really tell me anything. You need to show people what the actual change is going to be to your shoreline and show what facilities are being exposed to these threats,” he said.
What Lemmo wants, he said, “is a higher resolution model for what sea level rise will do to the Hawai`i shoreline,” including a beach vulnerability study. He has submitted funding requests, he said, and is hoping to work with the University of Hawai`i’s Coastal Geology Group to get the research under way.
Hoping for the Best…
Chip Fletcher is head of the Coastal Geology Group and associate dean of the School of Ocean and Earth Science and Technology. He is well known, both in and outside Hawai`i, for his research on shoreline processes and climate change. And while he harbors no illusions about the inevitable impacts of sea level rise, his outlook is not as bleak as one might expect.
“I see some rays of hope in Hawai`i,” he said, pointing to Lemmo’s request for help with a study of the effects of sea level rise on the coast. “He wants to know how sea level rise will affect beaches, and he wants it in a quantitative manner so he can use it in developing policy.”
Act 286, which amended the State Planning Act in 2012, “is a beacon of extreme hope,” he said. In addition, he was pleased to receive a phone call from a high-ranking administration official following up on a statement Fletcher had made to the effect that the only way to preserve beaches is to purchase coastal land. The official, he said “wants to discuss how to fund a study of this particular issue.”
Still, “we’re just at the beginning of planning,” he said. “Every single state department and county department needs to figure out how sea level rise and other factors impact our mission. There has to be a long, complicated discussion involving some sort of committee that will look at all the details – decreased rainfall, rising sea level, rising temperatures, greater exposure to tsunamis, storm surges, and hurricanes, heavier and localized flooding. There’s a plethora of potential impacts intersecting with a plethora of government activities. I don’t know anywhere this discussion has begun to take place.”
Pulling buildings and infrastructure away from the shore – an approach known as retreat – is just one of several ways to deal with sea level rise, Fletcher noted. Engineering is another, whether it takes the form of armoring the coast or building structures to withstand rising sea level and everything that entails.
“Forty years from now,” he said, “Hawai`i will see just the tip of the spear of accelerated sea level rise. The National Academy of Sciences has predicted that, globally, we’ll see between seven and 19 inches of sea level rise by 2050. That averages out around a foot.
“But Hawai`i for various reasons is going to see above-average sea level rise. By the end of the century, the National Academy is predicting between 20 and 55 inches, or upwards of five feet.”
“The first thing we need to ask ourselves is: What will the impact on us be of a one-foot rise in sea level? Probably the most immediate one will be a broadening and acceleration of coastal erosion,” he said.
Fletcher noted that his group had recently done a study of beach erosion on the islands of Kaua`i, Maui, and O`ahu, finding that 70 percent of them are experiencing loss. Nine percent were completely gone, usually as a result of seawalls built to protect private property.
On Maui’s north shore, almost 90 percent of the beaches were eroding, his group found.
As the erosion increases, Fletcher said, the state and counties will be forced to wrestle even more with coastal property owners who want to protect their land with seawalls.
“The DLNR has wrestled with this for some time,” he said. Today, “it does not very often award permits for walls, whereas 15 years ago they used to; it was standard practice.”
A one-foot rise in sea level “will come up in the storm drains,” he said. “On the sides of every road, you have these pukas. That’s where rainfall runs to the ocean, but the ocean is already coming up in some of these places – Waikiki and Kaka`ako on O`ahu, Kahului on Maui. We’ll see salt water ponding in the streets.”
Roads will be heavily affected as well. “A one-foot rise will make worse the seasonal high waves impinging on roadways that are already seasonally inundated,” he said, giving as examples Kamehameha Highway on the windward side and north shore of O`ahu.
“The areas that already have problems where the land and sea meet – those are already the first theaters of interacting with sea level rise,” he continued. “And this will only broaden and spread.”
Sea level rise will be most pronounced at high tide: “The highest tide of the day is where we’ll see the most flooding, the most wave overwash,” Fletcher said. “We’ll see waves running up on eroded beaches, crashing into houses – that sort of thing. Beach nourishment is going to become more common in Waikiki and Ka`anapali. Millions of dollars will be spent on sand replenishment where the economics justify it. We’ve had a few cases of neighbors hui-ing together to pay a coastal engineer to design a beach nourishment project, but that’s not always successful. Everyone thinks we can go out and find sand to put on the beach, but high quality sand is a rare commodity.”
Buried infrastructure will also be affected, he said. “Where we have not replaced the sewer lines, where they are still heavily perforated, we’ll see more and more infiltration and inflow as the water table rises.” Infiltration and inflow can hasten corrosion of pipes and overwhelm sewage treatment plants, resulting in sewage spills.
A rise in sea level of around a foot by 2050 is a near-certainty, given the thermal expansion of the ocean and melting of the world’s ice. “But Greenland is doing some alarming things,” Fletcher said. “Some glaciologists believe that as the ice melts back to where it is finally on bedrock, the rate of retreat will slow tremendously, but that neglects the melting that is occurring on the surface.
“A paper came out in May that predicts that by 2025, there is a 50 percent probability that the entire surface of the Greenland ice sheet will go into a state of decay… So has Greenland crossed, or is it approaching, a tipping point?” If that happens, the widely accepted models of the Intergovernmental Panel on Climate Change would have to be revised substantially.
But, Fletcher concluded, “these are off-the-cuff observations. In the end, we go along with the consensus of scientists. I hope sea level rise will be a slower process than many people fear. I don’t think the sky is falling, but I do think the longer we wait, the more expensive it will be to deal with.
“We can still plan for sea level rise adaptation in a very considerate, thoughtful manner. But government agencies have to take a leadership role and exemplify good adaptation practices. The private sector will see that happening and follow suit.
“We should hope for the best but plan for the worst.”