Hawaiʻi's dependence on coastal areas makes it vulnerable to sea-level rise. And thatʻs especially the case on the South Shore of Oʻahu.
Most of the focus on sea-level rise on Oʻahu is centered on Waikīkī. After all, it’s the economic engine for Hawaiʻi's tourism industry, producing $5 billion a year. And it's surrounded by water.
Waikīkī is also a testing ground for potential solutions to sea-level rise that could be deployed across the state. That's according to Chip Fletcher, who’s the dean of the UH Mānoa School of Ocean and Earth Sciences and Technology.
Fletcher says three issues are impacted by sea-level rise. First is erosion, and salt water in Waikīkī's drainage system that causes the system to fail when there's heavy rain. And then there's groundwater inundation, which happens when the natural drainage systems underground overflow with water.
Those create a compounding flooding effect when waves combine with flooding, reaching inland and raising the sea even higher. And each of those impacts requires its own architecture and engineering response to mitigate the effects.
Local architecture and planning firms like G70 and AHL have teams of people focused on sustainability issues for Waikīkī and other areas of the state. Firms like Sea Engineering and Pacific Engineering are also working on ways to protect not only buildings, but also Waikīkī Beach, where the state has pumped in close to 400,000 cubic yards of sand from offshore.
All of them are actively looking at small steps that can be taken to help protect properties from the rising sea. Ross Morishige is a principal architect at G70. He says some solutions in the future may include raising hotel lobbies higher. Or there are always temporary sandbags that can be deployed around Waikīkī during high tide to keep water away.
