A stream diversion study released this week has found that stream flows in the East Maui watershed are well below what's needed to provide a "sustainable natural habitat."

How much water will need to be restored to the streams is less clear, but the study completed by a U.S. Geological Survey team will be a key document for the state Commission on Water Resource Management, which is mandated by state law to set in-stream flow standards.
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The study includes an intensive investigation of five streams in East Maui and data gathered from 21 streams overall.
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All of the streams studied from Hanawi to Waikamoi are being diverted by the East Maui Irrigation Co. to provide irrigation water for Maui Pineapple Co. and Hawaiian Commercial & Sugar Co., and domestic water for Upcountry residents.

But the streams also are habitats for a number of native aquatic species, including five native freshwater fish, oopu; freshwater shrimp, opae; and a native snail, hihiwai. All of the freshwater species have a larval stage that is spent in the ocean, with the young oopu, opae and hihiwai returning to the freshwater streams to mature and breed.

In order to maintain their life cycles, the various species need to have streams that flow to the ocean. Where the streams are left dry, as at Honomanu, the habitat is effectively lost, but the issue for the commission is how much water needs to be restored to provide an adequate habitat.