Water Dept. Proposes Drilling of Mahinahina Exploratory Well

By Wendy Osher

Map of proposed Mahinahina Exploratory Well site, courtesy Fukunaga & Associates, Inc. and Maui Department of Water Supply, FEA.

The Maui Water department is proposing to drill and test an exploratory well in Mahinahina in West Maui. The project is intended to investigate the viability of backup sources of potable water during times of drought and when surface water treatment plants are undergoing maintenance.

The proposed site is located about three miles mauka of Honokowai Beach Park at the 1340 foot elevation.  The parcel is owned by the State of Hawai’i and is administered by the Department of Land and Natural Resources.

An estimated 60% of the total water demand in West Maui is supplied by surface water from the Lahaina and Mahinahina treatment plants.  In addition to periods of drought, periodic shortfalls have occurred during maintenance of the Honolua/Honokohau Ditch system.

After drilling and testing of the proposed well, the Maui Department of Water Supply plans to use the data to assess the potential for outfitting the well with a pump and for additional wells in West Maui.

A Final Environmental Assessment (FEA) has been filed with a Finding of No Significant Impact (FONSI).