Heavy rain across Hawaii this week has forced state officials to issue brown water advisories, prompting warnings for residents and visitors to avoid affected coastal and freshwater areas due to health hazards.
Stormwater Runoff Triggers State Advisories
The Hawaii State Department of Health began issuing the advisories on Tuesday, Oct. 27, 2026, after severe downpours triggered widespread stormwater runoff across the islands.
By Thursday, Oct. 29, the department reported that bacteria levels at Pounders Beach on Oahu had pushed past safe beach threshold levels.
Pollutants and Contaminants in Floodwaters
Stormwater runoff frequently turns ocean water brown and murky, signaling that the marine environment may be more polluted than normal.
According to the state health agency, floodwaters and runoff can contain overflowing cesspools, sewer manholes, pesticides, animal fecal matter, dead animals, various pathogens, chemicals, and associated debris.
Severe Health Risks from Bacteria Exposure
Officials advise the public to stay out of floodwaters and stormwater runoff.
Swimming, wading, or drinking water from any freshwater streams or ponds should also be avoided to prevent leptospirosis, a bacterial infection caused by the Leptospira bacteria.
The Golden Rule for Murky Shorelines
While stormwater runoff does not impact every coastal location equally, officials maintain a clear rule: stay out if the water is brown.
Tracking Active Advisories Online
A complete, up-to-date list of all waters currently impacted by stormwater across the state is maintained on the DOH Clean Water Branch System website, where residents can also check the latest status of each active advisory.
Additional details regarding the risks and transmission of leptospirosis are provided by the Hawaii State Department of Health.
