Coastal Erosion Inundates O'ahu Community for 15+ Years (Credit: Star Advertiser, Meteorologist Jessica Olsen)

Image Courtesy: Hawaii DOT

DISCUSSION: Oahu, home to some of the most breathtaking views cut from such mountain ranges as the Koolau’s or Waianae range, that some forget the daily issues that plague the small yet full island. Residents along Kamehameha highway on the Windward coast are facing a constant battle with eroding highways.
 
Most recently emergency repairs where conducted along Kamehameha highway to secure locations from Kaneohe, north to Kahuku. The result, an increase in traffic and rush-hour delays stemming from the repairs, residents are saying have been ongoing for at least a decade and a half. The Department of Transportation having made repairs two years in a row to the area.
 
What is to blame are the increase in sea-level rise due to climate change and high-surf leading to devastating erosion on Kamehameha highway. Repairs beginning February 11th, were estimated to cost between $3-4 million. A current resiliency study, which is expect to be completed in July, has indicated concern for the Hawaiian Islands as 20% of Hawaii’s roads will be inundated by the end of the century. This would put the cost of mitigation at an estimated $15 billion. State Rep. Sean Quinlan, representing Hauula and Kaaawa called on the Department of Transportation to create a strategic plan by 2021 which would include the replenishment of beaches and to reinforce the highway by 2024.
 
The US Climate Resilience Toolkit, managed by the National Oceanic and Atmospheric Administration (NOAA), has indicated that coastal erosion is “the process by which local sea level rise, strong wave action, and coastal flooding wear down or carry away rocks, soils, and/or sands along the coast.” It is estimated that more than 80,000 acres of coastal wetlands are lost annually, and coastal erosion costs are approximately $500 million per year in property loss in the United States.
 
Strategies to combat such issues include; shoreline stabilization, beach nourishment, and coastal restoration. These are merely similar adaptation and mitigation procedures the United States has been conducting for years. The efforts help to safeguard coastal communities, and restoring the area.
 
The US Geological Survey (USGS) has provided a Coastal Vulnerability Index, that may “help identify locations where coastal erosion may occur along undeveloped coastlines.”
 
For additional information on erosion on climate related issues, visit the Global Weather and Climate Center!
 
© 2020 Meteorologist Jessica Olsen