The Hawaii Department of Health has issued a brown water advisory for Waimea Bay on Oahu’s North Shore.

Officials say due to the river opening, stormwater runoff has entered coastal waters at the popular bay, resulting in possible contamination.

“The public is advised to stay out of flood waters and stormwater runoff due to possible overflowing cesspools, sewer, manholes, pesticides, animal fecal matter, dead animals, pathogens, chemicals, and associated flood debris,” said the department in the alert.

Not all coastal areas may be impacted by runoff, the department said, but “if the water is brown stay out.”

Anyone with exposure to brown water should practice good personal hygiene, and follow up with their primary care physician if they have health concerns.