The state Commission on Water Re-source Management has gutted its own efforts to keep the Maui Department of Water Supply from over-pumping the Waihe’e aquifer. Instead of having a trigger in place that could result in automatic designation of the aquifer as a strictly regulated water management area, the commission is now working on a Memorandum of Agreement to nudge the county in the right direction.
In July 2001, prompted by dropping aquifer heads and increasing salinity in the ‘Iao and Waihe’e aquifers, the Maui Meadows Homeowners Association petitioned the Water Commission to designate the aquifer systems as groundwater management areas.
In November 2002, commission staff had determined that both aquifers were indeed threatened by current and planned use and recommended that both be designated as groundwater management areas. Under the state Water Code, once an area is designated, CWRM takes control of the issuance and terms of water permits for new uses.
While the commission approved the staff findings, instead of voting to designate at once, it set four triggers that, if tripped, would result in automatic designation:
- If the 12-month moving average use for ‘Iao exceeded 18 million gallons a day;
- If the county failed, within two months, to sign a contract to develop and implement a numerical ground-water model of the ‘Iao and Waihe’e aquifer systems;
- If the midpoint of the transition zone at ‘Iao’s Waiehu deep monitor well rose above the -680 ft. elevation; and
- If the 12-month moving average water level in Waihe’e’s Kanoa test hole fell below the 6 ft. elevation at any time.
In July 2003, the county’s 12-month moving average use for ‘Iao exceeded 18 mgd and the aquifer was automatically designated. That September, the commission also discovered that it had made an error in determining the measuring point of the Kanoa test hole. The actual measuring point, the National Geodetic Survey had found, was 2.55 feet lower than the Water Commission staff had been led to believe; therefore water levels were below the 6 ft. elevation.
The Maui Meadows Homeowners Association and its attorney, Kapua Sproat of Earthjustice, argued for automatic designation of the Waihe’e aquifer since the Kanoa trigger had been met, but the commission, at its October 2003 meeting, disagreed, saying that the trigger was now “questionable.” The commission then directed its staff to work with Maui Department of Water Supply, the U.S. Geological Survey, and the National Geodetic Survey on getting better data on water levels in Waihe’e. Once the staff had a better understanding of the aquifer, it was to provide recommendations for amending the Kanoa test hole trigger. Also, the commission required the DWS to limit pumping at Waihe’e to less than 4 mgd, averaged over a month.
Over the next few months, the team determined all well measuring-point elevations and conducted recovery tests. (For these tests, pumping is stopped and changes in water level are noted; by this means, Water Commission staff could estimate the elevation of the midpoint of the aquifer’s transition zone.)
What the commission staff concluded from the results is that while water levels overall are lower (as much as two and a half feet) than originally thought, water level trends are “presently better than estimated back in November 2002.”
Data from the North Waihe’e well served as the basis for setting a trigger at the Kanoa test hole. Since the new data show that Kanoa and North Waihe’e wells are not as closely linked as originally thought (water levels differ by about a foot), linking trends at North Waihe’e to Kanoa “is no longer reasonable,” staff wrote. It concluded that the Kanoa trigger was no longer appropriate.
Immediate designation “could derail county initiatives to develop a Maui ground water numerical model and implement better pumping strategies,” a staff report stated. It went on to describe a range of possible triggers for automatic designation, based on the new data, should the commission favor this approach:
- When pumping exceeds 4.5 mgd, averaged over 12 months; If chlorides in any DWS production well exceed 160 milligrams per liter (mg/l) at any time; If construction of a deep monitor well does not start by 2007; and If the numerical ground water model is not completed by 2007
But the staff report stopped short of recommending the new triggers and instead advised the commission to eliminate the Kanoa test hole trigger altogether and defer designation. The staff also asked the commission to authorize it to pursue a memorandum of agreement with the Maui Department of Water Supply that would limit pumping from existing wells to 4.5 mgd and seek to ensure the timely completion of the West Maui groundwater numerical model and deep monitor well. The staff also recommended it be required to provide semi-annual reports on the status of the MOA and Waihe’e’s hydrologic conditions.
Rescinding the trigger approach “encourages and allows MDWS and stakeholders to concentrate their resources to more effectively manage the current situation,” the staff report stated. “Agency resources spent on avoiding trigger-based designation can be better spent on enhanced data collection, monitoring and analysis; more effective water resource planning; and improved stakeholder collaboration.”
Opposition
To the groups favoring designation, use of an MOA to encourage collaboration is tantamount to encouraging foot-dragging. And for that, some stated, there is no time.
In written testimony, William Meyer, former head of the USGS District office in Hawai’i, stated that water levels at the Kanoa test hole and at other locations in Waihe’e “are already considerably lower than the levels necessary to protect the integrity of the Waihe’e aquifer.
“As is commonly understood, pumping lowers water levels and, in order to avoid saltwater intrusion into wells, water levels under pumping conditions must not be allowed to fall below a value referred to as the equilibrium head in the [state] Water Resources Protection Plan. The equilibrium head would, by definition, maintain the top of the transition zone between freshwater and saltwater at some selected depth below the bottom of well fields. The sustainable yield values provided in the WRPP are, therefore, based on values for the equilibrium head for each aquifer,” he wrote.
Meyer had determined that the head is about 7.5 feet for the Kanoa well field and between 7 and 8 feet for the North Waihe’e well field. “Current water levels as determined by the USGS and even the Commission staff’s recovery tests are below the equilibrium heads for these well fields and, therefore, the Waihe’e aquifer is threatened by existing withdrawals of water.”
Earthjustice’s Kapua Sproat argued that not only is the Waihe’e aquifer already threatened, but also that the staff’s recommendation to allow pumping of 4.5 mgd would increase the threat to the aquifer. Referring to a June 2002 supplemental environmental impact statement for the East Maui Water Development Plan by hydrologists John Mink and George Yuen (who also devised the sustainable yield estimate for Waihe’e) Sproat noted that based on the current well configurations in Waihe’e, no more than 4 mgd should be pumped from the aquifer. (There is well at Kupa’a that some say could help distribute pumping more evenly throughout the aquifer and increase the sustainable yield beyond 4 mgd, but it is not yet functional. According to Mink and Yuen, with optimally placed wells, Waihe’e could yield as much as 8 mgd.)
Sproat said that Water Code and the public trust doctrine instruct the commission to adopt a precautionary approach when dealing with fresh-water resources that may be threatened. What’s more, she said, the commission lacked a statutory basis to reconsider the triggers set in November 2002. She urged the commission to designate Waihe’e as a groundwater management area at once.
In defending his staff’s recommendation to go with an MOA in lieu of designation, commission chair Peter Young noted that chloride levels in all wells were found to be excellent. To this, Sproat reminded Young that the reason the commission uses water levels instead of chloride levels to determine the health of an aquifer is because there is a lag time – from 18 to 35 years – between when an aquifer is over-pumped and when that is manifested in rising chloride levels.
“If we sit and wait until chloride levels exceed or get near the EPA levels, it’s too late,” she said, adding that her clients want to err on the side of caution in dealing with their main sources of water.
Young responded, “It doesn’t appear we need to designate at this time, but we will monitor…[and] make sure certain levels are not exceeded. That also errs on the side of caution…Essentially, by keeping the [designation] process open, it allows staff to react in a timely fashion.”
Sustainable Yield
In addressing Sproat’s contention that pumping should be limited to 4 mgd, CWRM staffer Roy Hardy told Young, “There is merit to keep it at 4, however, there is an alternative source, the Kupa`a well, that could increase [the sustainable yield] beyond 4.” Hardy admitted, “We would feel more comfortable at 4, but realize that the user has been pumping more than 4.5 and things have been stable.”
While the commission seemed to be moving toward a limit of 4 mgd, Jeff Pearson, deputy director of the Department of Water Supply, pushed for more generous limits. He told the commission, “We feel we can do our best to meet this 4.5 mgd based on a moving average. There may be times it will be hard to limit ‘Iao to 18 and Waihe’e to 4.5, but we’re looking at alternative water uses [surface water from ‘Iao]…We’re not out to damage the aquifer. We will try to do our best to stay at 4.5.”
(The Maui County Water Use and Development Plan identifies 10 proposed projects in the ‘Iao-Waihe’e area that, if built, may increase the strain on both aquifers: Waiehu Kou Phase III, Waihe’e Mauka ag subdivision, Malaihi ag subdivision, Waiehu ‘Aina subdivision, Wailuku Country Estates, Kehalani Mauka, Maui Lani, Waiko Mauka ag subdivision, Waiko Baseyard subdivision, and Kahului Industrial Park.)
When Young asked if Pearson could limit pumping to 4 mgd, Pearson responded unfavorably, saying that his crystal ball was “getting cloudy.”
When it came time to vote, commissioner Stephanie Whalen moved to approve staff’s recommendation with the amendment that the MOA require DWS to limit pumping to 4 mgd instead of 4.5. The motion was approved, with commissioner Meredith Ching opposing.
In the Meantime
In August, the commission will get its first scheduled update on the status of the MOA and Waihe’e’s hydrologic conditions. While there is no deadline for completing the MOA, Hardy says it’s likely a draft will be ready in the next couple of months. As of mid-March, the county and commission staff were still in the discussion phase.
Without a signed MOA, technically, the county is free to pump more than 4 mgd. What happens if it takes forever to complete a final MOA, or the county violates it after it’s signed?
“Good question. That’s what we are wondering ourselves,” Hardy says. Without automatic triggers, he says, “The commission is free to do what it wants. We could go back to the commission and say we don’t have an MOA signed, and they could designate, or say go back and work on it some more. It’s in the commission’s court.”
— Teresa Dawson
Volume 14, Number 10 April 2004