Search by provider name, city, service area, or state.
State utility hub
Browse the indexed community water systems in this state. Each profile brings the provider’s payment routes and household protection policies into a single, practical guide.
Public Water Authority
Service area: Oʻahu, including Honolulu and the Board of Water Supply service communities
Population: More than 600,000 people and approximately 231,000 homes and businesses across the metro Oʻahu service area.
Public Water Authority
Service area: Windward Oahu and Pearl Harbor service areas
Population: 631,389 people (EPA SDWIS active CWS PWS HI0000331)
Public Water Authority
Service area: Waipahu, Ewa, Kapolei, Nanakuli, and Waianae areas of west Oahu
Population: 217,479 people (EPA SDWIS active CWS PWS HI0000335)
Municipal Department
Service area: Wailuku and County of Maui Department of Water Supply service areas
Population: 74,511 people served according to the EPA queue; the County of Maui Department of Water Supply serves Central Maui and other county water systems.
Public Water Authority
Service area: Joint Base Pearl Harbor-Hickam, Oahu federal installation service area
Population: 65,230 people (EPA SDWA queue estimate for HI0000360)
Public Water Authority
Service area: Mililani
Population: 50,573 people (EPA SDWA queue estimate for HI0000367)
Municipal Department
Service area: Lihuʻe-Kapaʻa and Kauaʻi County
Population: 34,854 people (EPA SDWA queue estimate for HI0000400)
Municipal Department
Service area: Makawao / Maui County
Population: 29,868 people (EPA SDWA queue estimate for HI0000213)
Municipal Department
Service area: North Kona
Population: 29,581 people (EPA SDWA queue estimate for HI0000131)
Municipal Department
Service area: Wahiawa / Oahu
Population: 23,348 people (EPA SDWIS 2026Q2 estimate for HI0000333)
Municipal Department
Service area: Lahaina / Maui
Population: 20,065 people (EPA SDWIS 2026Q2 estimate for HI0000214)
Municipal Department
Service area: WAILUKU
Population: 74511 people (EPA SDWIS 2026Q2 active CWS estimate for HI0000212)
Municipal Department
Service area: HILO
Population: 39477 people (EPA SDWIS 2026Q2 active CWS estimate for HI0000101)
Public Water Authority
Service area: SCHOFIELD BARRACKS
Population: 37920 people (EPA SDWIS 2026Q2 active CWS estimate for HI0000345)
Hawaii directory notes
This state hub brings together 14 indexed community water systems, from city departments and public authorities to investor-owned systems and smaller regional providers. A service area may cross municipal boundaries, so use the provider name and service address on your bill when choosing a profile.
The most important distinction is between a directory listing and an official account channel. Water Ledger provides a structured starting point; the utility’s own payment portal, published rate schedule, customer-service office, and mailed notice control your account. Compare the payment route, billing frequency, emergency number, and customer-protection notes before relying on a page for a time-sensitive decision.
If you are helping a household with a high bill, leak, or delinquency notice, open the utility profile and review the payment, shut-off, and leak-adjustment guides together. Keep the bill, account number, confirmation receipts, repair records, and notice dates available when speaking with the provider.