DWS West Maui system’s Maximum Reliable Capacity, 3-Year Water Usage Forecast released

The County of Maui Department of Water Supply (DWS) on Friday, Nov. 14, 2025, released its Maximum Reliable Capacity and 3-Year Water Usage Forecast Projection for the West Maui System, which analyzes how much water the system is expected to reliably deliver to Nāpili and Lahaina service areas over the next three years.

The study can be found on the DWS Engineering Division's page at www.mauicounty.gov/214/Engineering-Division.

The Maximum Reliable Capacity and 3-Year Water Usage Forecast Projection examined well-pumping capacity, regulatory pumping limits and recent production data. It also accounted for uncertainties and assumptions related to mechanical failure, human error and weather events. Researchers assessed the likelihood and duration of various system disruptions, including downed well pumps and periods of low or no intake flow at treatment plants.

The report found that peak demand exceeds the system's reliable supply by 41.8%. With the addition of the Kahana Well, expected to come online in early 2026, the shortfall would be reduced but demand would still exceed reliable capacity by 15.7%. The Kahana Well still requires permits from the state Commission on Water Resource Management before it can become fully operational.

"Even with the Kahana Well in operation, additional supply will be needed to fully meet current demand and support future growth," DWS Director John Stufflebean said. "We are exploring every option for finding new water sources and expanding existing supplies, but ongoing conservation and careful management remain critical as demand continues to grow."

For more information, contact DWS Engineering Division at (808) 270-7835.