Wetlands in Waikiki

Climate change, and the rise in sea levels that are a key feature, are processes that move at a glacial pace, so to speak. But some would say government policymaking — including the planning for ways to adapt to all this extra water on the land — moves just as slowly.

So the question is: Which will get here first, the flood waters or the adaptations to them? This is a particularly critical question for Oahu’s south shore, where some valuable properties that are already in the flood zone could be vulnerable to further threats through the rise of sea levels globally.

Sea-level rise, according to the most current models, is projected to be about a foot by 2050 and somewhere in the range of 2.5 to 6.2 feet by the end of the century, said Chip Fletcher, author of a recent book on climate change and an associate dean at the University of Hawaii School of Ocean and Earth Science and Technology. Some planning officials say developers were already bound to develop adaptations to flooding, long before climate change became such a potent issue.

However, some may not be factoring in scenarios beyond the waves that will wash farther inland, Fletcher said. There’s also the groundwater table that will be pushed up.

"As the ocean goes up with global warming, this groundwater comes up and it’s going to flood our communities," he said. "It’s going to create wetlands where our roads and our buildings currently are.

"And everybody thinks sea-level rise is causing a problem by waves coming over the beach and waves coming over Ala Moana Beach Park, and everything. That is a problem, but we also have this other issue of groundwater."

Fletcher co-authored an assessment published last year in the journal Nature Climate Change. Flooding generally occurs within a kilometer-wide shoreline zone, and projected sea-level rise of a meter would produce widespread inundation, partly from sea water but also from the groundwater it pushes up, he wrote.

Further, said Kem Lowry, UH professor emeritus, climate change also means more intense storms that blow in more often. Project plans that once factored in the risk of a 50- or 100-year storm surely must be recalculated based on more frequency, he said.

Lowry, former chairman of the UH Department of Urban and Regional Planning, said people in low-lying, coastal Honolulu already are changing their concept of what’s "normal."

"One sunny day, I was trying to sell an old car to a used-car guy in Mapunapuna," he recalled. "And I drove through some puddles of water. He said, ‘You’ll want to wash off your car — that’s sea water that backed up. Sea water doesn’t drain out the way it used to.’"

A video depicting precisely what Lowry described in Mapunapuna, along with an animated computer model of how a meter-high rise in sea level would inundate Waikiki, can be viewed on Fletcher’s website on the subject (links are on the left-hand panel at www.soest.hawaii.edu/coasts/sealevel).

The one area on Oahu’s south shore that’s still in flux, where adaptations are on the drawing board, is Kakaako. Anthony Ching is executive director of the Hawaii Community Development Authority, which oversees the redevelopment of the largely industrial area to a more upscale mix of commercial and residential properties.

"Buildings have always had to cope with issues of water tables and flooding," Ching said. "If you’re in a flood zone, you’re already making choices. You don’t stop building because of the fear of a rising water table or inundation; you design accordingly."

One project in Kakaako is the Howard Hughes Corp.’s Ward Village, and two of its condo towers won HCDA approval in August. Ching said the plans would make the projects more resilient to flooding by raising the base floor level by four feet. Making that accommodation, either with the addition of a concrete slab or adding fill material to the grade of the site, will be a common choice in Kakaako development, he said.

Other considerations building planners could incorporate, Ching said, include:

» Leaving the bottom floor dominated by open space with minimal assets to be damaged by a flood.

» Using columns both as design elements and to bolster the structural integrity during storm events.

» Incorporating modular building systems, such as boilers, that can be replaced without an entire redesign.

» Placing electrical panels, backup generators and other storm-vulnerable project components on an upper floor.

» Opting for lower-level and subterranean parking to minimize the worst of the flood damage.

Climate change policy has become a very big deal in Hawaii, for obvious geographic reasons. A month ago, President Barack Obama appointed Gov. Neil Abercrombie to serve on his Task Force on Climate Preparedness and Resilience. Its recommendations are due Nov. 1, 2014.

Two years ago, the state Office of Planning held workshops to develop a climate change policy to guide Hawaii’s adaptation to sea-level rise, a policy that was enacted during the 2012 session, said Jesse Souki, the planning office director.

That new law means climate-change guidelines, including the evaluation and promotion of adaptation strategies, must be part of the state’s and counties’ planning processes, Souki added.

However, exactly how that happens is still in the formative stages, and that’s one of Lowry’s roles in all this. One of his projects for the Office of Planning is coming up with a system for engaging the community in making the issue of adaptations to rising sea levels part of the system of revising the regional development plans. The community is often best at identifying what needs to be protected, he said.

"I recognize that people have images of climate change, but it’s not very personal," Lowry said. "We need to talk to people about where they think flooding is likely to be worse because of clogged-up streams, get information on the ground."

The main concern lies in convincing the people with the most influence over adaptation strategies — landowners and developers — that making their properties more capable of withstanding an assault from sea water and groundwater deserves a high priority, he added.

"A lot of technical work is being done," he said. "The technical work is a lot about exposure, what areas are likely to be inundated.

"There’s some technical uncertainty about that, about the amount and distribution of the flooding, but also about the timing of the onset," Lowry said. "So there’s an understandable reluctance to invest a lot of money and effort to adapt to something we’re not sure about."