A ground-water inventory of the Waialua basal-water body, Island of Oahu, Hawaii
Open-File Report 78-24
Prepared in cooperation with Board of Water Supply City and County of Honolulu, Honolulu, Hawaii
- Robert H. Dale
The Waialua basal-water body underlies an area of about 18 square miles on the north shore of the island of Oahu, Hawaii. The basal-water body is a body of fresh ground water that floats on saline ground water in a highly permeable and porous basaltic aquifer.
Inflow to the basal-water body is from the deep infiltration of applied irrigation water and from leakage through a low permeability ground-water dam. Outflow from the basal-water body is from basal-water pumpage and leakage through low-permeability boundaries that separate the basal-water body from the ocean.
The basal-water flux, computed as either the sum of the inflow terms or the sum of the outflow terms, is about the same value. The basal-water flux is 55 million gallons per day, (206,000 cubic meters per day), based on the sum of the outflow terms.
The effective porosity was computed at 0.09 by a time-series analysis of the covariations in deep infiltration, pumpage, and basal-water head. The volume of basal water in storage is estimated to be 1.4 x 1011 gallons (5.4 x 108 cubic meters).
Pumpage from the basal-water body can be increased. The most efficient development method is the skimming shaft. If shafts were used, an additional 15 million gallons per day could be pumped on a sustained basis.
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- USGS Numbered Series
- A ground-water inventory of the Waialua basal-water body, Island of Oahu, Hawaii
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- Open-File Report
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- U.S. Geological Survey
- x, 76 p.
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- United States
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