Smoke Test on Kūhiō Highway to Locate water Tunnel Exposed by Hanalei Hill Landslide

The Hawai‘i Department of Transportation announced they will be conducting a smoke test on April 15 on the water tunnel exposed by the March 11 landslide on Kūhiō Highway (Route 560) near the intersection of Hanalei Plantation Road.

HDOT is performing the smoke test in an effort to locate the water source feeding the tunnel and cut the source off so crews can improve the stability of the highway.

To locate the entrance(s) to the tunnel, large quantities of smoke will be blown into the tunnel by jet fans to force smoke out of any upstream entrance(s). Historic maps from the 1800s suggest that the water tunnel was connected to systems in the Princeville area.

The smoke test will use non-toxic, odorless, white, or gray smoke. During the test, drones will be flown to assist with spotting smoke exiting the tunnel. If you see smoke during the smoke testing operation, call 808-220-4226.