“We’re bringing coals to Newcastle.” That’s how Don Thomas, a geochemist with the University of Hawai`i’s Department of Geology and Geophysics, described recent findings in a presentation to the state Commission on Water Resource Management last March.
Thomas’ Hawai`i Scientific Drilling Project, which began boring a 11,541-foot-deep hole into the ground near the Hilo airport in the late 1990s, has discovered that despite current ideas about island aquifers, freshwater can be found in artesian aquifers and pillow lavas far, far below sea level, deeper than 10,000 feet.
While this discovery doesn’t save the day for rainy Hilo, which has “got all the water it needs,” Thomas said, the find is causing scientists to rethink a long-accepted paradigm of freshwater recharge on islands.
As most textbooks would explain it, freshwater is stored in perched aquifers, dikes, or basal aquifers, and in those basal aquifers, freshwater extends slightly below sea level until, eventually, it transitions into salt water.
But according to Thomas, that’s not the whole story.
Using a cookie-cutter bit tipped with tiny diamond chips, the team drilled through a thin layer of Mauna Loa lava down to lava from its older sister volcano, Mauna Kea. The purpose of the hole was to allow scientists to better examine the volcanism that produced Hawai`i, since it is not well understood, Thomas said. The project team wanted to explore the deep structure of the Big Island and, among many other things, characterize its water resources.
From the core left by the drill, similar to the ice cores taken from polar regions, scientists sampled rocks and water, made geophysical measurements, and discovered some astonishing things. For one, the Hilo side of the island is sitting on a 1,500-foot layer of gravel and sand. “Not very comforting,” Thomas said.
But more important, at least to hydrologists, is that there are multiple layers of freshwater and salt water below sea level. At the Hilo bore hole, fresh water extends from 300 to 500 meters, he said, and below that, down to 1,500 meters, lies cold salt water. But deeper still, artesian aquifers were found and an old Mauna Kea soil and ash layer was found to be discharging one billion gallons of freshwater a day into the ocean. Pillow lavas at the greatest depths also contained fresh water, he said.
“There is ten times more freshwater in Mauna Kea than current models would have predicted,” he said. “What the hole shows is that there are different mechanisms for storing water.” What’s more, the deep soil and ash aquifer isn’t just a receptacle for old, stored water that was slowly buried as the island subsided. It’s being recharged by rainfall.
Spurred by the results from Hawai`i island, the project team plans to drill a similar hole through Haleakala where east and west Maui intersect to discover any hidden water sources there. While Hilo doesn’t need the extra water, Maui – where fights over freshwater have plagued the island for decades – does. But at the March meeting, to prevent anyone from jumping to conclusions, Thomas warned that Haleakala is older than Hawai`i’s volcanoes and has undergone more weathering, which may affect runoff and percolation on the island.
What was found at the Hilo bore hole “doesn’t mean there’s all kinds of [underground] water on Maui. At this point, we don’t understand the hydrology of any of the islands,” which is why he and his colleagues want to continue their work, Thomas said. “I don’t want to say we are going to … find what we found at Mauna Kea and Mauna Loa. I can only say that [island hydrology is] not what we thought it was.”
‘What does it mean?’
Roy Hardy, hydrology program director for the Water Commission, says while the presence of deep freshwater has been common knowledge for some time, the implications for water resource management are taking longer to understand.
CWRM first became involved with the Hilo project because staff worried about the drill going too deep and hitting a geothermal layer.
“We put in a lot of conditions for mitigating that,” he says.
Over the years, the project has sent a number of reports to the commission and “we knew about these things in 2003, but it was kind of like, ‘What does it mean?’ From 2003 until now, they’ve been analyzing [the cores]. It’s one of those long academic studies and they’re now coming out with a better conceptual model [on the hydrology],” he says.
Hardy says the commission plans to mention the Hilo findings in the Water Resources Protection Plan, which it is preparing as one of the components of the state Water Plan.
“There may be other areas where big mountains butt against each other. It would appear that water from the lower aquifer is not ancient water. It looks like it’s actively getting recharge. We have to rethink how much recharge is getting into the upper aquifer as opposed to the lower. Right now, we only have the recharge going into upper aquifer,” he said.
Commission Tightens Grip
On Waters of Central Maui
“It seemed kind of mundane until you all burst into applause,” Water Commission chair Laura Thielen said after its vote March 13 to designate the West Maui watersheds known as Na Wai `Eha as a surface water management area, the first such designation since the Water Code was passed in 1987.
In 2006, Earthjustice, representing Hui o Na Wai Eha and Maui Tomorrow Foundation, Inc. filed a petition requesting that the commission either recognize the watersheds of Waihe`e, Waiehu, `Iao, and Waikapu Streams (collectively, Na Wai `Eha) as part of the `Iao Ground Water Management Area, or designate the four watersheds as a surface water management area. At its March meeting, the commission determined that because there are “serious disputes” over the surface water resources, it should designate Na Wai `Eha as a surface water management area.
Whether for ground or surface water, designation as a water management area requires all users of water from that area – except for people or entities with appurtenant rights, for domestic water use by individuals and those using catchment systems –to have a permit from the Water Commission.
To get one of those permits, they must show the use meets several criteria:
• The use can be accommodated by the source.
• It is a reasonable-beneficial use.
• It will not interfere with any existing legal use of water.
• It is consistent with the public interest; land use designations, as well as county general and land use plans and policies.
• It will not interfere with the rights of the Department of Hawaiian Home Lands.
Within one year of the published notice that the area has been designated, all existing users of Na Wai `Eha water who want to continue their use must file a permit application with the Commission on Water Resource Management. While new use applications can be submitted at any time, any existing user who fails to meet the one-year deadline will be considered a new user. New uses will only be accommodated once all the needs of existing users have been met.
While Thielen called it an historic decision, she quickly added, “Being the state, you can be assured it’s not going to be quick.” The Legislature had just announced the DLNR’s budget, which includes a significant number of cuts in positions at its Division of Aquatic Resources and at the Commission.
At the commission’s March meeting, attorneys for Hui o Na Wai `Eha and Maui Tomorrow, for the Office of Hawaiian Affairs, and for County of Maui all testified in support of the designation, as well as several members of the community and activist groups. Attorneys representing Alexander & Baldwin/Hawaiian Commercial & Sugar and Wailuku Water Company, as well as staff from both companies, attended the meeting, but did not testify.
After the commission’s vote, Maui County corporation counsel Jane Lovell asked how the commission would deal with the fact that one party – Wailuku Water Company – controls the diversion system that currently provides the county with water for its municipal system. When the `Iao aquifer was designated as a groundwater management area, the county and a housing developer both applied for water from the same source, Shaft 33, which was located on land owned by the developer. Because the permit application had required signatures from both entities, the county’s existing use application — which lacked the developer’s signature — was rejected and the county was lumped in with the new use applicants. While the `Iao aquifer was able to accommodate the county’s use, Lovell seemed worried about how the Na Wai `Eha permitting process would play out, since it would seem that some existing water use applicants would need to obtain signatures from WWC.
“We don’t want every user to have to get a signature from the diverter,” she said.
Earthjustice attorney Kapua Sproat also raised the signature issue at the commission’s April meeting during a discussion of a new draft permit application for existing uses.
While the draft permit application was a non-action item on the agenda and the commission did not vote on whether or not the landowner signature would be required, Hardy says that the commission had taken a position on the matter when it decided the dispute over Shaft 33.
“The result was, hey, the commission requires it,” he says.
Even so, the commission plans to consult with its attorney on the matter.
“The commission doesn’t want to encourage disputes,” Hardy says. “We have some ideas. We may make a change [but] have to clear it with the AG [attorney general].”
With regard to the ongoing contested case hearing on a petition by the Maui Tomorrow Foundation and Hui o Na Wai `Eha to amend the interim instream flow standards of Na Wai `Eha, hearing officer and commission member Lawrence Miike is expected to complete his recommendations to the commission some time this summer. Commission stream program manager Ed Sakoda said at the March meeting that if the flow standards are not amended before the Na Wai `Eha surface water use permits are issued, interim permits might be issued instead. The commission would then have five years from the time the use applications were filed to amend its flow standards and issue final permits.
— Teresa Dawson
Volume 18, Number 11 May 2008
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