$11.5 Million Waikamoi Flume Renovation 90% Complete

By Wendy Osher

Maui County Water Department director Dave Taylor presented an update of the Waikamoi Flume renovation project saying it is now about 90% complete at a cost of about $11.5 million.

The project was implemented to address an old and leaking wooden flume that was losing much of the water that was being transported to the Olinda Water Treatment Facility.

Waikamoi Flume on the West end near the Waikamoi Stream. Photo courtesy: Draft Environmental Assessment, and Munekiyo & Hiraga, prepared for the County of Maui Department of Water Supply.

The flume was designed with 17 intakes to deliver water through a reservoir system to the Olinda WTF, which provides about 1 mgd or around 10% of water for Upcountry water users.

“The reservoir system is actually filled by the dam directly… and then after it stops raining, this flume can work for weeks or months longer to take water seeping out of the ground and deliver it to our plant,” said Maui Water Department director Dave Taylor during testimony today.

The new flume is built out of a rectangular aluminum pipe to prevent corrosion and enable stability caused by erosion and flooding.  It stretches a little over a mile and is located at the 4,000 foot elevation within the Waikamoi Forest Reserve.

Taylor said the location of the flume posed difficulty for planning and construction because it is in an area where there are no roads, making costs associated with instillation difficult to project.  Global Construction was tasked with rigging the new pieces for installation as the parts were flow in by helicopter and installed by hand.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

The original contract price was $11.2 million with change orders representing $450,000 or 4%, according to Taylor.  “We are ecstatic that change orders were only 4%.  I think that is incredibly low, and it shows that the design, engineering team, and the contractor did a fantastic job,” said Taylor.  “A third of the change orders were just from the access road which blew out during some big storms.  So, doing work out in the middle of nowhere like this has its risks.  I think this has been a very successful project,” he said.

Taylor cautioned against the project being viewed as a final “end-all” solution to ongoing water supply issues Upcountry saying, “It will be great, but not as great as maybe some people are thinking.”

According to Taylor, “Even if this captures 100% of the water that was lost, you’re really just keeping one plant that processes 1 mgd reliable a little bit longer.  It’s not as important as the lower systems (like) the Piʻiholo WTF that processes 5 mgd and has a 50 mg reservoir; and the Kamaole WTF which processes 5-6 mgd that has no reservoir.”

“Every drop of water is precious and this is an important project, especially because it’s at a high level.  If we capture more water up there, we don’t have to pump it.  But I don’t want everyone to think that just because this is done, that all of a sudden, all of the Upcountry water woes will be over,” said Taylor who noted that it is one of many improvements that need to be made.

Committee Chair Michael Victorino commended the construction and design team for their work on the project saying that costs remained well below initial estimates of $13- to $14-million.  “Now we’re going to see a consistent level, and I think that’s what we were looking for rather than more water,” said Victorino who noted that much of the water was being lost due to leaks in the old flume.

“It’s one of the good stories for the day,” said Victorino.

Old Waikamoi Flume. File photo courtesy: Draft Environmental Assessment, and Munekiyo & Hiraga, prepared for the County of Maui Department of Water Supply in May 2012.

Old Waikamoi Flume. File photo courtesy: Draft Environmental Assessment, and Munekiyo & Hiraga, prepared for the County of Maui Department of Water Supply in May 2012.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

Waikamoi flume replacement. Photo courtesy Maui Department of Water Supply.

Waikamoi Flume on the West end near the Waikamoi Stream. Photo courtesy: Draft Environmental Assessment, and Munekiyo & Hiraga, prepared for the County of Maui Department of Water Supply.