The urban center of Honolulu makes up about 23% of the state’s population, but accounted for almost 40% of water consumption in the state in 2024.

With a population of nearly 345,000, the metropolitan area — marked by its high rises and resorts as opposed to the rest of the island of Oʻahu — used more water last year than all three other counties combined. But that doesn’t necessarily mean that individual city dwellers are using more than their rural peers.

Several of the county’s top water consumers, including the airport and the University of Hawaiʻi Mānoa, are located in urban Honolulu. The state doesn’t have recent data breaking down whether the majority of the water is guzzled by industry, irrigation or residents.

The average single-family household in Honolulu County uses about 9,000 gallons of water each month, according to the county Board of Water Supply. But the biggest individual water users are actually golf courses, large resorts and industrial facilities.

Oʻahu’s Biggest Water Users

The Marine Corps Base in Kāneʻohe uses about 7,000 times the amount of water as the average Honolulu County resident each month, according to water usage statistics in the recently released state data book for 2024.

Golf courses made up almost a third of the biggest water consumers on Oʻahu in 2024. There’s one at the Marine Corps Base in Kāneʻohe, which tops the charts as the most water-hungry consumer in Honolulu County. 

Several resorts, including the Hilton Hawaiian Village Disney Vacation Resort & Spa and the Sheraton in Waikīkī, are also in the top 25 users, as are Hawaiian Cement and United Laundry Services, which does laundry for the hospitality and health care industries.

Water Use By County

Despite being surrounded by the ocean, fresh water is in relatively short supply in Hawaiʻi. Drought looms large on Maui and the Big Island, and hillsides look parched in the summer heat. Parts of the state are under Groundwater Management Area protections, allowing officials to enhance protection of the aquifers. 

Little by little, water consumption across the state has been declining. Statewide, the annual amount of water used decreased by about 4% — or almost 3 billion gallons — between 2022 and 2024, according to the state’s data book.  

For a period in 2022, the Honolulu County Board of Water Supply asked consumers to use 10% less water out of concern that there might be a shortage due to the Navy’s fuel contamination crisis at Red Hill. But that goal ended up being tough to achieve.

However, it’s hard to get a county-by-county picture of what industries or uses are driving water consumption. The most recent data from the U.S. Geological Survey on the major uses, including domestic consumption, irrigation and livestock, is a decade old.

“Data Dive” is supported in part by the Will J. Reid Foundation.

Correction: A prior version of this story included incorrect scales of measurement.