The Mauna Kea Watershed Alliance (MKWA) is a coalition of public and private landowners committed to the restoration of native forest on Mauna Kea, Hawaii’s tallest and most sacred mountain. Since 2014, MKWA has led the Waipahoehoe, Hawaii Island Groundwater Replenishment Project, which will restore 1,100 acres of native forest in a critical water recharge area on the “Big Island” of Hawaii. The project will ensure preservation of over 2 billion gallons of water per year, recharging the local aquifer and supporting surface water hydrology within the Wailuku River watershed.

The majority of domestic potable water in Hawaii comes from groundwater sources. Without active management, non-native plant species like gorse and Australian tree fern can take over and impact native ecosystems in drastic ways, greatly increasing wildfire risk and altering natural hydrologic pathways. Unfortunately, over half of Hawaii’s native forests have been lost to date along with important recharge function from groundwater sources.

Since 2014, the construction of ungulate proof fences and targeted invasive species management has helped to advance MKWA goals of restoring native forest and associated ecosystem services. Fences are the best way to initiate restoration of native forests in Hawaii, in this case providing a barrier to non-native/feral cattle, sheep and pigs currently found in the area. While the initial fence line has been constructed at Waipahoehoe, the feral ungulates that were caught within the fence still require removal, a difficult and costly endeavor. Additional funding is needed to complete this step in the project prior to implementing final restoration through outplantings of native species.