Maui County is on the cusp of modernizing windward Haleakala's mile-long, 1930s-era, sievelike Waikamoi flume.
Reconstructing the flume is expected to provide Upcountry with a much-needed bump in its depleted water supply during drought, officials said last week.
The undertaking will need parts to be flown in by helicopter to a delicate nature reserve. The project is estimated to cost up to $15 million and take two years to complete. Hopefully, work will start in the next month or so, said Department of Water Supply Deputy Director Paul Meyer.
It’s estimated to cost up to $15 million to repair the 1930s-era, leaking Waikamoi flume, which captures water from East Maui streams and channels it to Upcountry reservoirs. Last month, the state Office of Environmental Quality Control ruled the project would have no significant impact on the environment. Work on the project could begin as early as next month.
Maui News file photo
"We need every drop," said Upcountry Council Member Gladys Baisa. "I'm very excited it's finally going through. It's really bad up here."
With a rebuilt flume to capture and carry water to Upcountry reservoirs, farmers, ranchers and residents could get 1 million gallons more per day This is not part of Mayor Alan Arakawa's proposed water meter list solution, though.
Upcountry residents are regularly asked to conserve water. And Waikamoi's 30-million-gallon reservoirs are down to just 500,000 gallons.
The redwood flume takes in water from several streams within the Koolau Forest Reserve to supply Kula, Waiakoa, Keokea, Ulupalakua and Kanaio, according to the recently completed final environmental assessment.
Meyer said the county is still hammering out contract and construction details. He declined to name the project contractor.
"This is a very sensitive project, and very near and dear to us in a treasured watershed," he said.
Arakawa said the flume's reconstruction is just one of several new water sources he wants for the Valley Isle's agricultural hub.
"Our administration is pushing very hard. It's not to just talk anymore," he said.
Arakawa said the rebuilt flume would "stabilize" Upcountry water availability.
"This is a great project. Long overdue," said Kula community advocate Dick Mayer. "The flume provides a nice, dependable supply to an area in need most - without uphill pumping costs."
The County Council started funding the project almost four years ago. The county passed the last major obstacle last month after the state Office of Environmental Quality Control found no significant impact with the 742-page environmental assessment.
The flume can deliver 2 million gallons a day and serve 10,000 Upcountry residents. It begins at the Haipuaena stream and ends at Waikamoi stream. The length is at a slope along a twisting path about 4,000 feet above sea level, Meyer said. It traverses lush and treacherous terrain such as cliffs and 50-foot gulches.
The plans make it resemble a king-size Erector Set. But it's really another low-maintenance aqueduct.
The county design has hardly changed "because it works, and will for a long time," Meyer said.
But the new flume will be made of noncorrosive materials like aluminum, stainless steel and composites. The contractor also must keep the flume flowing during construction, he said. The engineers may use pipes or troughs around construction.
The 2-foot-wide, foot-deep flume actually runs almost parallel along the mountainside with a wooden catwalk above it. The new walkway will be on top, but with a grated floor and railings. The Hawaii Occupational Safety and Health Division had fined the county for the decrepit catwalk a couple years ago.
And the state Commission on Water Resource Management ordered the county to fix the leaks around the same time.
To help maintain water quality and lessen clogs, the flume is loosely covered with boards. In a downpour, the flap top also allows excess water to splash over the sides instead of bursting the system, a general design feature the renovated project will keep, Meyer said.
The flume is "almost impossible to maintain at this point," he said. With many trusses and trestles and worn-out wood, it probably will be rebuilt in short sections.
The bumpy 7-mile access road needs repairs, too, Meyer said. The road starts in Olinda but doesn't follow the entire flume, which explains the need for a helicopter.
The flume has a number of stone foundations. Some will be poured anew and timber supports replaced with metal poles.
The "bountiful" reserve must stay closed to the public, Meyer said. Hikers can inadvertently bring in seeds. Thirsty invasive plants, such as fireweed, make it harder to replenish the watershed and blight the land.
"It can't come soon enough," said Warren Watanabe, executive director of the Maui Farm Bureau, of the flume repair project. "It's so dry up here."
The region has long-held family farm and ranch traditions rooted in the rich volcanic soil, cool air, year-round sunny skies and its clear and once-abundant water.
"Hopefully, the flume really is a sign of more to come," Watanabe said.
* Chris Hamilton can be reached at email@example.com.