The Waikamoi Flume carries potable water over a 1.1 mile distance through the Koolau Forest Reserve on Mount Haleakala providing water to residents in Upper Kula in Upcountry Maui. Originally constructed out of redwood over a hundred years ago, the flume has experienced frequent leaks, blowouts, and foundation issues resulting in constant repair work by maintenance workers under hazardous conditions. Faced with Maui County’s goal to restore a dependable clean water supply to the people of Upcountry Maui, the Department of Water Supply contracted KAI Hawaii, Inc. to design a new flume system that could meet the capacity needed and be safely maintained.
Dangerous conditions and lack of infrastructure severely limited access to the flume by the contractor. Materials and equipment had to either be carried by hand or air-lifted in and out, limiting many design, material and construction options.
However, creative use of aluminum for the entire structure provided excellent corrosion resistance and significantly reduced the weight of the individual components, reducing the overall cost of the project.
Historically, the Hawaiian referred to this region as Wao Akua, a remote mountain area only inhabited by spirits. The region is only used as a watershed and access to the area is limited to trained professionals to protect the native plants and to control invasive species and animals. During construction, the contractor followed strict protocols in the watershed and set up a vehicle and equipment decontamination station to avoid inadvertent transportation of invasive plant species into the conservation area.
This project won several awards:
ASCE Hawaii – 2015 Outstanding Civil Engineering Achievement Awards – Best Large Project Award (Construction > $10 million)
ACECH – 2016 ACECH Engineering Excellence
- Grand Conceptor Award
- People’s Choice Award