State to oversee aquifer on Maui
By Christie Wilson
Advertiser Neighbor Island Editor
WAILUKU, Maui — The state has designated 'Iao Aquifer a groundwater management area and will be taking control of the resource from the county, which failed to keep pumping below required levels or to find enough additional water sources for Maui's most populated areas.
Once the designation becomes official with a formal public notice expected to be issued Monday, owners of wells that tap into the aquifer, including Maui County, will have one year to apply for a water use permit from the state Commission on Water Resource Management. Residences and other small, individual water users with private wells are exempt.
The permit process will provide better protection of the precious resource and ample opportunities for the public to weigh in on how the water is used, according to Roy Hardy, branch chief of the commission's Groundwater Regulation Branch.
Mayor Alan Arakawa said the 'Iao water situation should have been dealt with long ago by county officials, and he has no problem with the state taking control.
The designation was automatically triggered when the 12-month moving average for withdrawals from the 'Iao Aquifer exceeded 18 million gallons per day in June. The moving average is calculated using pumping data from the preceding 12 months.
The aquifer's sustainable yield is 20 million gallons per day (mgd). The 12-month moving average last month was 18.06 mgd.
Hardy said it is likely the pumping levels will go even higher this month and in August and September, when water demand peaks.
The Maui Meadows Homeowners Association in Kihei had petitioned the water commission in 2001 to designate the 'Iao Aquifer and the neighboring Waihe'e Aquifer, which has a sustainable yield of 8 mgd, as groundwater management areas. Both resources are located beneath the West Maui Mountains.
The association was concerned that overpumping ultimately would result in saltwater intrusion into wells, which would threaten Maui's drinking water supply.
At a hearing in November, the commission set the 'Iao trigger at 18 mgd — 90 percent of the sustainable yield — in lieu of issuing the groundwater management area designation.
A different trigger was set for designation of the Waihe'e Aquifer, whose pumping levels have been at about half of its sustainable yield. That trigger involves maintaining the transition zone between the fresh and salt water tables at an acceptable depth. Hardy said that depth remains within the acceptable range.
Court action to continue
After the commission decided against the designations, the environmental group Earthjustice filed a Hawai'i Supreme Court petition in May on behalf of the association seeking to compel the state agency to protect the aquifers.
Earthjustice attorney Kapua Sproat said yesterday that the court action will continue because the designation covers only the 'Iao Aquifer. She said it doesn't make sense to leave out Waihe'e, because the commission has determined that the aquifers are "hydraulically connected."
Sproat said the 'Iao designation is a mixed blessing, because it means the aquifer will get greater protection, but it also means that pumping has reached levels that threaten the resource.
She said the State Constitution and State Water Code require the water commission to take a precautionary approach to protecting water resources and not wait for the situation to become dire before acting.
Maui Meadows Homeowners Association member Jim Williamson, a retired civil engineer, has been following the water issue for 15 years.
"The main thing we're trying to do is get the load off the aquifer, and we hope that's the direction the commission is going to take," he said. "The only aquifer (Kihei has) is 'Iao. If we lose 'Iao because it gets salted up, we're dead in the water."
Better data sought
In addition to setting the 18 mgd pumping trigger, the commission required the county to enter into a contract to create a numeric water model to provide more accurate data about how much water exists in the aquifer.
Both the county and state agree it is important that more scientific information be collected, but now that the state has taken control of 'Iao, the county may no longer be obligated to go through with the $1 million study.
The county has budgeted $292,000 in the current fiscal year to pay for the initial phases of the work, which is to be conducted by the U.S. Geological Survey.
Water department spokeswoman Jacky Takakura said yesterday that water director George Tengan would be meeting with commission officials today to request that the state share the cost.
The water commission has been considering designation of the 'Iao Aquifer at various times since the 1980s. During that period, the county Department of Water Supply attempted to find other resources as South Maui became one of the fastest-growing areas in Hawai'i.
Plans to make use of wells in East Maui and pipe the water across the island were stalled because of environmental and water-quality concerns.
In December, the water department began filtering water from the 'Iao-Waikapu Ditch to supplement the groundwater system.
