Kaua‘i streams and ground water levels are nearing all-time lows, U.S. Geological Survey records show, prompting some local residents to take notice and the state to search for answers. From May to July, streamflow on the island was 48 percent
Kaua‘i streams and ground water levels are nearing all-time lows, U.S. Geological Survey records show, prompting some local residents to take notice and the state to search for answers.
From May to July, streamflow on the island was 48 percent of the median for those months over the past year.
“This was the lowest flow for any three-month period since 1986 and the lowest flow for May to July ever recorded,” the USGS Pacific Islands Water Science Center Web site states.
At the Wailua River north fork where the 2006 July monthly mean discharge was 38 cubic feet per second, the flow was 53 percent of the median for that month based on USGS surface water data records since 1912.
But there are no diversions upstream of the gaging station, according to the USGS, that would explain the disappearing streams and vanishing waterfalls community members have reported.
The station, operated by Dale Nishimoto of the Honolulu field office, is equipped with a satellite transmitter delivering updates every hour.
The state Department of Land and Natural Resources is investigating four complaints that water is being diverted away from Secret Falls, which goes over the north fork of the Wailua River.
The unproven complaints allege that waterflow is being effected by the production of the movie “Tropic Thunder,” agricultural use, an eco-tourism company and Kaua‘i Island Utility Cooperative.
The state water commission’s deputy director, Ken Kawahara, has said so far investigation has determined the complaints to be rumors and drought to be the leading suspect.
In general, Kawahara said most Hawai‘i streams are supplied directly from rainfall.
National Weather Service rainfall records indicate most gage totals to be in the “below normal” range on Kaua‘i, supporting the Department of Land and Natural Resources claim.
The state water resource commission reported that Kaua‘i has received less than 60 percent of normal rainfall amounts at eight of 17 rainfall stations from Jan. 1 through July 31.
Neighbor islands O‘ahu and Maui showed similar low streamflow and ground water levels, according to USGS data.
On Maui, for instance, the Honopou Stream flow was 45 percent of the median for July.
And on O‘ahu, the Kalihi Stream flow was below the median every month but November over the past year.
Ground water levels corresponded to the low stream flows on Kaua‘i.
For instance, water levels near Hanapepe decreased January through July and are “some of the lowest ever recorded for May, June and July,” a USGS Web site states.
