The Hawaiʻi Department of Transportation has designated a traffic emergency zone along Kūhiō Highway near Lumahaʻi Beach on Kauaʻi’s North Shore after heavy rain on Halloween caused slope erosion that encroached on the roadway and threatens public safety.
The designation covers milepost 5.4 on Kūhiō Highway (Route 560) and will allow the department to expedite repairs by streamlining procurement and waiving certain permitting requirements, department officials said during a public emergency hearing on Veterans Day.
The lane nearest the ocean has been closed since Nov. 9, after erosion reached the highway. Traffic is currently alternating through the remaining open mauka (inland) lane, with a stop sign at both ends.
The Transportation Department plans to maintain alternating traffic while contractors work to stabilize the upper portion of the slope. Once initial stabilization is completed, the department expects to shift to daytime lane closures during construction.
The repair project is expected to include installing soil nails and a shotcrete wall along the lower portion of the slope. Crews also plan to replace a damaged culvert and repair pavement affected by the erosion.
Officials at Wednesday’s meeting said flooding that contributed to the slope failure occurred when water overtopped the roadway, washing away a nearby section of the slope. Officials did not identify the culvert as being directly within the slide area.
The department also intends to address drainage conditions to help prevent similar incidents.
The representative said the flooding occurred uphill from the culvert and was caused by water flowing over the roadway rather than a blockage in the nearby culvert.
Residents also raised concerns about plugged culvert inlets and erosion along other portions of Kūhiō Highway toward Hāʻena and Hanalei.
Officials from the department added that its materials and testing laboratory regularly evaluates slope stability along Route 560 to identify vulnerable areas for potential projects. However, the department acknowledged it does not currently have the resources to address every vulnerable location along the highway.
The Transportation Department also noted erosion near the pavement at Waikoko and said it will do a follow-up inspection.
The department has not established a construction timeline for the repairs. Officials said they will issue public service announcements with lane closure schedules and additional project information once those details are determined.
The traffic restrictions are expected to remain in place until crews can complete the necessary stabilization and repair work.
