In the East Maui village of Wailuanui, farmers cultivate kalo, also called taro, in irrigated terraced patches. In the mid-1800s, plantation owners tapped East Maui’s rain-fed streams to grow sugarcane in the island’s dry central valley. This resulted in a vast system of ditches, flumes, and tunnels that diverted water from the valleys and gulches that had once watered East Maui’s wetland taro patches. In 2016, Hawaiian Commercial & Sugar Co. ended its operations on Maui and announced it would restore several of the streams that the irrigation system had previously diverted, including the East and West Wailuanui Streams. As a result, many taro farmers needed to restore or replace outdated water delivery systems that had fallen into disrepair. In 2018, the Hawaii State Legislature appropriated funds for water system improvement projects in East Maui. This included the Wailuanui Water System Improvements project, which involved the reconstruction of an irrigation ditch that supplies water to Wailuanui’s wetland taro patches. GBI’s Maui Region started working on this project in September of 2021 and completed it in April of 2022.
GBI’s scope of work included the removal of dense vegetation and the installation of soil nails, shotcrete, and grouted riprap in the irrigation ditch. The project site was in a mountainous area that had limited accessibility, which meant that heavy equipment could not be brought into the work zone; this made the project more labor intensive. Additionally, GBI used an MD 500 helicopter to bring in the rock for the grouted riprap. Despite these challenges, GBI successfully reconstructed the irrigation ditch, and by doing so, improved the delivery and quality of water in the East and West Wailuanui Streams.