Despite population growth, West Hawaii has actually been using less water than was projected in a 2017 plan designed to protect the Keauhou Aquifer.
The reduction in water use occurred even before the 2020 coronavirus pandemic that reduced visitors to the island, said Water Department Manager/Chief Engineer Keith Okamoto in a presentation Tuesday to the county Water Board.
The County Council is scheduled to be briefed on the plan in early August.
The county also will send well permit applications to the non-regulatory Aha Moku system for review and recommendations for the protection of traditional and customary practices that might be affected by the application in question.
The aquifer system stretches from Makalawena Beach to north of Kealakekua Bay and includes Kaloko-Honokohau National Historical Park. The document establishes a comprehensive plan for the use of water resources in the area.
Among other mitigation measures, the update includes county plans to reduce reliance on wells lower in elevation and offset existing needs and future demand with more high-level sources of water.
The plan’s recommendations also include encouraging partnerships with major landowners in the region, developing alternative sources of nonpotable water and continue monitoring activities.
“We want to use the highest quality water for the highest purpose,” Okamoto said, responding to a question from Chairman William Boswell on county plans to reuse treated waste water for parks and golf courses. “That would relieve us of the burden to provide potable water for those nonconsumptive purposes.”
The updated plan follows a 2017 ruling by the state Commission on Water Resource Management denying a petition by the National Park Service to impose stricter regulations on taking water from the aquifer. The water department had Honolulu-based Fukunaga and Associates conduct the study, then compared it with newer data coming in from other state studies.
“All the pumpage that’s in the aquifer system is monitored by CWRM and they compare that with the sustainable yield,” Okamoto said. “Twenty years down the road and we’re still doing OK as far as protecting the aquifer.”
The study sets 38 million gallons a day as a sustainable yield of water, and 28 mgd as the anticipated demand. Drawdowns have come in much less than that and, in fact, indicate consumption growth is about five years behind originally anticipated.
“We’ve been in compliance with all six recommendations even prior to this 2017 report being finalized,” Okamoto said.
The study used for projections the existing water use and projected use based on entitlements, as well as county zoning and estimated use by zoning classifications and population growth estimates.
Members of the Water Board were generally pleased with the study.
Still, noted member David De Luz, tapping the water is just one part of the equation. The county needs more waterline infrastructure to really solve the problem.
“Just having the availability of water is only one part of it,” De Luz said. “Getting it where it has to go is a big part.”
(This article has been clarified: The County Council is scheduled to be briefed in early August on a 2017 water use plan designed to protect Keauhou Aquifer, but will not vote on the plan. The study sets 38 million gallons a day as a sustainable yield of water, and 28 mgd as the anticipated demand.)
