A Category 3 or 4 hurricane will drive 20 to 30 feet of seawater inland. This could happen within a 12- to 24-hour time period and could do everything sea level rise (SLR) will accomplish in the coming decades.
This scenario is actually predicted by FEMA as likely for Honolulu at any time into the future decades.
Each year of SLR will only push the future hurricane storm surge further inland. On top of SLR, there is groundwater inundation creeping up year after year that brings water much further inland.
Hurricane Scenario 1A Wave Activity shows portions of O‘ahu that are likely to be inundated by storm surge, including Honolulu Harbor, Honolulu International Airport and key infrastructure.
Image courtesy of University of Hawai‘i’s Department of Ocean and Resources Engineering
Storm surge will create massive damage hundreds of yards inland to sewer, water and electrical systems, shutting down the Sand Island Waste Water treatment plant and depositing massive amounts of raw sewage around downtown areas. Honolulu Airport's reef runway would likely be destroyed and tourism will come to a complete stop.
Just think about that--no airport and raw sewage everywhere with a totally useless and shut down railway system. And no Civil Defense planning at all has been done for this incredibly likely future scenario!
Not only will rail be shut down after hurricane storm surge, it will likely take many months to get the infrastructure around the stations back up to operational status. (Maybe this is why we will need bike lanes?)
This all could be avoided by planning the rail route further inland, such as along H-1, away from all of these problems! And why wasn't this done? Because rail is a real estate project, not a commuter transportation system! This is a state Department of Transportation-Federal Transit Administration-financed real estate project.
This is why the truth will come out in the future and the very bad rail route planning fiasco will be exposed for all to see. Billions more will have to be spent (which is apparently the intent of this bad plan).
Meanwhile, groundwater inundation and land subsidence is currently underway and it is totally ignored by the city, HART and so-called HCDA urban planners in low-lying coastal areas such as Kaka'ako and the south shoreline, where five to six other rail stations will be located.
Kaka'ako and the South Shore of O'ahu will experience increasing persistent flooding due to the rise of the ground water table (a lighter fresh water lens) that sits atop sea level. All our urban and rail "planners" totally ignore this scientific fact and eventuality. How could so much money be spent on such an incredibly bad plan?
According to "Assessment of groundwater inundation as a consequence of sea-level rise" (University of Hawai'i: Water Resources Research Center and SOEST/Geology and Geophysics), " 0.6_m of potential sea-level rise causes substantial flooding, and 1_m sea-level rise inundates 10 percent of a 1-km-wide, heavily urbanized coastal zone. The flooded area including groundwater inundation is more than twice the area of marine inundation alone. This has consequences for decision-makers, resource managers and urban planners, and may be applicable to many low-lying coastal areas... "