Brown water advisory issued for Hanalei Bay after heavy runoff

Brown water at Hanalei Bay was enough for county ocean-safety crews to tell swimmers, surfers, families and visitors to stay out of the water until conditions improved. The Kauai Ocean Safety Bureau said no swimming or other ocean activities were allowed at the North Shore bay because heavy runoff had pushed brown water into the nearshore zone.

Officials posted warning signs and were monitoring the area. For anyone headed to Hanalei, the county’s message was simple: do not guess based on how the bay looks from shore, and do not rely on word of mouth when runoff is involved. Current conditions were being routed through a county lifeguard, the county’s Safe Beach Day page, and the Ocean Safety Bureau at 808-241-4984.

The advisory fit a pattern the North Shore has seen repeatedly during heavy rain. Five days earlier, the county had issued a broader notice for Hanalei Bay and all north-facing shores except Anini Beach because of the same runoff and brown-water conditions. County and state advisories in March and April also showed that Kauai had been dealing with multiple brown-water alerts during this spring’s rain events.

The public-health concern is not just muddy water. The Hawaii Department of Health’s Beach Monitoring Program says advisories can be issued when sewage leaks or spills, heavy rains or other conditions affect beach water quality. State guidance says people should stay out of water that looks brown or murky, especially after storms, because storm water can carry pathogens and other pollutants. State materials also advise avoiding brown water for about 48 to 72 hours after rain stops.

Hanalei Bay has been on watch before. The county issued a similar brown-water advisory there on Jan. 27, 2025, and watershed planning for the bay identifies sediment, bacteria and nutrients as the main pollutants of concern. Department of Health watershed studies have used bacteria and sediment data to verify impairments and guide source assessment, underscoring that this is a recurring water-quality problem, not a one-off visual nuisance.

For North Shore residents, the warning carried a practical takeaway: when runoff turns Hanalei Bay brown, the safest move is to wait. Until the water clears and the county changes its guidance, the bay is a place to watch from shore, not enter.