County water director discusses options to meet Upcountry needs
Officials in Mayor Alan Arakawa’s administration are holding “high-level discussions” with Alexander & Baldwin officials about taking more water out of the Wailoa Ditch system for Upcountry customers as A&B’s subsidiary Hawaiian Commercial & Sugar Co. phases out production at the end of the year, Department of Water Supply Director Dave Taylor said.
He mentioned his recommendation to pursue more water from the East Maui irrigation system that taps streams in the East Maui watershed and the administration’s negotiations to a council committee in late January. He did not give a specific amount of water sought.
The county water department has an agreement with East Maui Irrigation Co., an A&B subsidiary, to draw 12 million gallons a day with an option for 4 mgd more from the Wailoa Ditch.
Taylor made his comments during an interview with The Maui News about Upcountry water plans and projections included in a proposed findings of fact, conclusions of law and decision by hearings officer Lawrence Miike on the East Maui watershed contested case proceeding. Taylor also emphasized that his comments in the report were made about a year ago during public hearings.
“There is a huge uncertainly of actual demand and infrastructure needs,” Taylor said.
The report said that the water department anticipated having to develop between 4.2 mgd and 7.95 mgd to meet demands through 2030. The population served by the Upcountry system, which is predominantly supplied by surface water, will grow from 35,251 (9,865 water connections) to 43,675 people. The report notes that there were 1,852 applicants on the waiting list for water meters as of June 30, 2014.
Water use based on meter readings between 2004 and 2013 was nearly 8 mgd, varying between 6 mgd and 10 mgd, according to the report. Taylor said that “if we turned everything on” during the wet season, the water department could produce 15 mgd, but during the dry months two surface water treatment plants could have no water. He noted that in December the low demand was 3.2 mgd with the high at 7.2 mgd.
“There is a huge difference in demand,” said Taylor. “It’s not easily predictable. Past performance does not predict future results.”
About 80 to 90 percent of water in the Upcountry system comes from three surface water systems – the Wailoa Ditch, the Olinda and Kahakapao reservoirs that collect water from the Waikamoi, Puohokamoa and Haipuaena streams, and the Piiholo reservoir that stores water from the same streams and Honomanu Stream.
The water department recently repaired the 1.1-mile Waikamoi Flume, from which the water department estimated losing about 40 percent of total flow through cracks and holes in the old wooden structure. Taylor said that there was and are no meters on intakes into the flume so there is no way to obtain accurate measurements of how much more water is flowing into the reservoirs.
The remaining water comes from aquifer wells, with the Haiku Well able to produce 0.5 mgd; the Pookela Well, 1.3 mgd; and two Kaupakalua wells, 1.6 mgd, for a total of 3.4 mgd from ground water sources. In times of emergency, the water department can tap up to 1.5 mgd from the Hamakuapoko wells, according to the report.
The water department currently has no plans to drill new production wells because “they are very expensive, use a lot of energy and there are some legal and procedural difficulties,” the report said. It notes that “water is heavy” and requires a lot of energy to move thousands of feet uphill. Makawao, for example, is at the 1,800-foot elevation with wells pumping water from sea level.
The wells would provide relief during dry periods, when the water department often has to post water-use advisories. Taylor said that building a well requires other infrastructure to operate and to connect to the Upcountry system.
So for two dry months, will the community make building “a massive system that may sit for eight months” a priority? he asked.
“We would like to have more wells” and to meet the entire 2030 demand, but that comes with a price tag and is not his sole decision to make, Taylor said.
“If we are willing to pay enough, they are technically feasible,” he said.
One project the water department is eyeing is building a 100-million-gallon to 200-million-gallon reservoir at Kamole Weir Water Treatment Plant, through which water from the Wailoa Ditch runs, according to the report.
“Raw water storage at the Kamole WTP is more cost-effective than providing backup capacity by extensive additions of basal groundwater wells, which require high long-term energy expenditures,” the report said.
The total six-year estimated cost of the reservoir is more than $25 million. The report said that $1.5 million had been budgeted for land acquisition for the reservoir this fiscal year, but Taylor said that no location has been selected.
The reservoir project is in the “exploratory stage,” he said. “We have not even requested a detailed design . . . not reached that point yet.”
“There have not been firm decisions,” Taylor said, and he declined to reveal whether any more funds would be allocated for the project in the next fiscal year that begins July 1.
In addition to providing drinking water for Upcountry customers, the water department also supplies nonpotable water to the Kula Agriculture Park. The water is stored in two reservoirs with a total capacity of 5.4 mg, according to the report.
About 40 percent of the water running through the Upcountry system is used for agriculture, the report said.
* Lee Imada can be reached at firstname.lastname@example.org.