WAILUKU - A U.S. Geological Survey study 4 years in the making and released this week describes the effects of taking millions of gallons of water daily from "the Four Streams" of Na Wai Eha that originate in the West Maui Mountains.
USGS also presented a complex matrix showing the amounts of stream water needed to return to each of the Central Maui streams to revitalize flora, fauna and aquatic life; to recharge the aquifer and to promote taro growing. The report also details the amount of water necessary to resume mauka-to-makai, or mountain-to-ocean stream flow, something not seen for more than a century of stream diversions to irrigate sugar crops.
"The idea is to give people and the commissioners the tools to understand the effects of a decision to divert water and adjust those diversions," said USGS hydrologist Delwyn Oki, who presented the findings of his 176-page report to about 50 people in Maui Economic Opportunity's classroom Tuesday night.
Here's a few of the USGS study's conclusions, which relied on data obtained between 1984 and 2009:
* Aquatic life and taro are better able to thrive when water is restored to streams and water temperature is lowered.
* Restoring minimal amounts of continuous stream flow would enable fish that already exist in the streams, such as shrimp and gobies, to thrive.
* Restoring instream flow would help recharge the underground aquifer that Maui County pumps for domestic water use.
* Increasing instream flow also would improve water quality in the aquifer.
* To achieve constant mauka-to-makai stream flow, the minimum amounts of water required would be: 1 million gallons per day for Waihee Stream, 1.3 mgd for north Waiehu and 1.1 mgd for south Waiehu (they converge to create Waiehu Stream), 5.2 mgd for Iao Stream and 6.8 mgd for Waikapu Stream.
It's estimated that 70 million gallons per day is diverted from the Iao, Waihee, Waikapu and Waiehu streams by the Wailuku Water Co.
The results were obvious conclusions to many who oppose the more than century-old practice by sugar producers, several audience members said on Tuesday.
"This report justifies our cause," said taro farmer John Duey of Hui O Na Wai Eha, one of the groups seeking the return of water diverted from streams. "Now it's up to the commission to do its job."
East Maui Irrigation President and Hawaiian Commerical & Sugar Co. Water Management Director Garret Hew said he couldn't comment on the report Wednesday because he hadn't had time to review it. HC&S gets water for some of its fields from the Wailuku Water Co. system.
HC&S Senior Vice President of Agricultural Operations Rick Volner said that, technically, the record is closed on the Na Wai Eha hearings, so supposedly new information can't be introduced.
But the USGS said that it did the work, in large part, to help create solutions to the ongoing water disputes.
"In recent years, it has become increasingly apparent that competition exists for the limited surface-water resources in Central Maui," according to the report. "However, quantitative instream flow standards for Central Maui streams have not been established. Additional scientific information, including ecological information and stream-flow data, is needed to establish technically defensible instream flow standards that will support equitable, reasonable and beneficial allocation of the water resources."
"We have no position," Oki said about the Na Wai Eha contested case. "We are just presenting the information."
In October, commissioner and hearings officer, Dr. Lawrence Miike, recommended restoring about half of the diverted water back to the streams. The Commission on Water Resource Management is deliberating and will release its decision before the end of this month, state officials have said.
Oki said he gave commission staffers a copy of the report on Monday, and he briefed commissioners late last year on his preliminary findings. In fact, the commission as well as Maui County and the state Office of Hawaiian Affairs were all partners in developing the USGS report, according to the document.
The report can be found on the USGS Hawaii website at pubs.usgs.gov/sir/2010/5011/. The USGS plans another meeting on its findings at 8 a.m. on Friday at the American Water Works Association Hawaii Section 36th Annual Conference in Honolulu.
USGS Pacific Islands Water Science Center Director Stephen Anthony said officials held Tuesday's meeting on Maui first in order to give residents here a "heads up" about the findings. Anthony said officials would return in two months for a follow-up meeting on the report.
* Chris Hamilton can be reached at email@example.com.