When is flooding going to close the road to Hanalei? When will it re-open? Just check the Hanalei Watershed Hui Web site. Residents of the North Shore of Kaua‘i are always concerned about Hanalei Road being flooded and closed to
When is flooding going to close the road to Hanalei? When will it re-open?
Just check the Hanalei Watershed Hui Web site.
Residents of the North Shore of Kaua‘i are always concerned about Hanalei Road being flooded and closed to traffic during storms. Road closures trap some in Hanalei while others are not allowed go down the hill and over the bridge into town to work or return home.
The road is closed by Kaua‘i County when waters from the Hanalei River spill over the banks and cover the highway pavement, making it unsafe for driving. With years of experience, the police know that when the water height reaches 7 feet on the measuring stick on the Hanalei Bridge, the road will be flooded.
Last winter’s flooding caused the road to be closed five times in February and March alone, with the biggest storm causing closure for almost 17 hours. Without warning these events can be a serious inconvenience.
The Hanalei Watershed Hui, working in close collaboration with the U.S. Geological Survey, has created a link on the Hui Web site — www.hanaleiwatershedhui.org — that provides a near-real time graph of the height of the water in the Hanalei River at the USGS gauging station, approximately 4 miles upstream from the site where the road floods.
At that gauging station the USGS has instruments that measure water height, rainfall, and also sample to measure the amount of mud (sediment) in the river.
The instruments measure the height of the river and then transmit the data to a satellite.
That is downloaded by the USGS on the Mainland, interpreted, and loaded into the USGS national Web site. The Hui Web site has a direct link to the Hanalei data.
When the river is actually flooding, there is usually about a 15 minute lag between measurement and when the data appears on the Web site.
The Hanalei Watershed Hui staff has analyzed the data from 14 road closings over the past two years and has discovered that the road is closed approximately an hour after the water level reaches the 7-foot mark on the graph.
Similarly, the road will re-open approximately an hour after the water level goes down to the 4.5-foot level on the graph.
Last March, over 12,000 hits were recorded on the Hui Web site during the rainy period by people wanting to know if the road was going to close.
For more information, call Dr. Carl Berg 639-2968 or Matt Rosener 826-1985 at the Hui.
The Hanalei Watershed Hui is a non-profit 501c3 corporation which depends on donations to keep its Web site and stream gauging projects going.
Donations to the “Gauging Project” are tax-deductible and can be made out and sent to: Hanalei Watershed Hui, P.O. Box 1285, Hanalei, HI 96714.
