In Partnership with the Southern Weekend

History behind Hawaii’s largest freshwater source

Water conservation is so important to the sustainability of Hawaii. Rachel Pacarro talks with the Board of Water Supply to learn about the source of Hawaii’s water.

Sponsored by Board of Water Supply

Fresh water on the island of Oahu comes from underground aquifers. The largest aquifer on the island is in and around the Pearl Harbor area. As rain falls over the two mountain ranges, gravity pulls the water through lava rock and eventually collects at the lowest point on the island, Pearl Harbor. The Board of Water Supply has their largest water source located in the area, and it has an interesting history.

During the 1940s, the United States shipped over so many military personnel that they doubled the islands population. This resulted in a large increase in the demand for water. Plans were made to address the problem, and the Board of Water Supply built the single largest water facility for the city of Honolulu. December 6th, 1941was the first day of construction, but was halted due to the war efforts. The Halawa facility was fully operational by August of 1944.

The pumps at the Halawa facility are located underground where the freshwater aquifer is located. They constructed a 284 foot long shaft at an elevation of about 23 feet above sea level, skimming the top layer of the aquifer. The facility has undergone many important upgrades and renovations over the past 10 years to increase water quality and better emergency preparedness equipment.

The Halawa location is the only Board of Water Supply facility with limited public access for educational purposes. For more information, please visit boardofwatersupply.com or email them at tours@hbws.org