Waimea Residents Report Brown Tap Water, DWS Investigates and Flushes Lines

Rust-colored water flowing from kitchen taps pushed residents across a wide swath of Waimea's South Kohala neighborhoods to call the county for answers last week, with reports of discoloration arriving from as far apart as Lālāmilo Farm Lots and the Lakeland Subdivision.

The Hawaiʻi County Department of Water Supply issued a Temporary Water Discoloration Notice on March 31 covering Hiʻiaka Street and portions of Puʻukapu and the broader Waimea-Kamuela area. Businesses and households throughout the South Kohala water system were among those affected, and DWS crews launched flushing operations across the distribution system the same day.

For anyone still seeing brown or discolored water: DWS advised running cold water for several minutes until it clears before using it for drinking or cooking. Hot-water appliances, including washing machines and dishwashers, should be left off while discoloration persists, as the sediment can stain fabrics and fixtures. Residents with compromised immune systems who want additional assurance can use bottled water for drinking and cooking until sampling confirms clarity. Anyone whose water does not clear after flushing was advised to contact DWS directly.

The department said routine laboratory samples from the South Kohala system had returned within normal limits and that there was no reason to believe the water posed a contamination risk. DWS characterized the additional water-quality testing it ordered as a measure taken out of an abundance of caution, and said it would release results publicly once available.

The probable trigger was maintenance work. On April 1, DWS issued hand-carry shut-off and connection notices for limited pipe repairs in neighborhoods adjacent to the affected zone. Pressure changes and system transitions that accompany that kind of repair work commonly disturb sediment or mobilize rust inside aging iron-pipe mains, producing the brownish discoloration that Waimea households reported. No specific turbidity or discoloration measurements had been published as of April 4.

The episode points to a recurring tension in rural water systems on the Big Island: distribution networks covering widely spaced communities like Waimea's mix of farm lots and residential subdivisions can react sharply to even routine maintenance when pipe infrastructure is aging. DWS said flushing operations would continue and that the public would be kept informed as test results came in.