The Department of Water Supply is an agency of the County of Maui. Our mission is to provideclean water efficiently. We provide water to approximately 35,700 services on Maui and Molokai. The water we provide meets all state and federal water quality standards. Take a look around our site to learn more. The Department needs your help! Please conserve water. For easy ways to use less water (and save money), see our tips on Water Conservation.