Find Your Water Source

The Maui Department of Water Supply serves five main sections within the County: Central Maui, Upcountry Maui, West Maui, East Maui, and Molokai. The system with the most customers is the Central system, which includes Wailuku, Paia, Kahului, and Kihei.

The next largest system is the Upcountry water system, which is actually the largest geographically. This includes Kula, Pukalani, Makawao, and Haiku.

Lahaina is third, then Molokai, and then Hana. Water on the island of Lanai is provided by a private company.

Where Does Water Come From?

  1. Water evaporates into clouds and are brought to the island by trade winds from the northeast.
  2. The rain forest in the mountains catches the clouds.
  3. Cool mountain air condenses the clouds to form rain.
  4. Some of the rain flows into streams and ditches, while some percolates down to underground aquifers that provide most of the water.
View a graphical representation of the water cycle, courtesy of USGS.

Water Quality Reports
Water quality reports describe where your water comes from, anything that may have been detected in the water, and how those results compare to standards for safe drinking water. It shows that your water is safe to drink and that it complies with federal and state standards.
For questions about the quality of your water, call:
  • The EPA hotline - (800) 426-4791
  • The Hawaii State Department of Health, Safe Drinking Water Branch - (808) 984-2400, ext. 64258
  • Toll-free from Molokai and Lanai - 1-800-468-4644, ext. 64258
  • The Department of Water Supply Laboratory - (808) 270-7550
Water Conservation
The Department of Water Supply's job is to find more sources to satisfy that demand. That's not easy, and it's very expensive. There are many ways you can help us conserve the supply of water that we already have:
  • Use low-flow plumbing fixtures
  • Find and repair leaks
  • Turn off water when washing your car
  • Only use the dishwasher or laundry machine when it's full
  • Don't flush the toilet unnecessarily
  • Turn off the water while shaving or brushing your teeth
  • Water the yard in the early morning or evening
  • Landscape your yard with plants that are appropriate for your area's rainfall
  • Attach a rain sensor to your sprinkler system
  • Water the yard, not the sidewalk, the driveway, or the road