The Florida Department of Health in Okaloosa County has issued a health advisory for Cinco Bayou in Fort Walton Beach, warning against water-related activities after tests found elevated bacteria levels.

• The department said tests completed Wednesday, Aug. 5, indicate the water quality in Cinco Bayou does not meet the recreational water quality criteria for Enterococcus bacteria recommended by the Florida Department of Health.

DOH-Okaloosa advises against any water-related activities at the location due to an increased risk of illness in swimmers. The department noted that drinking water is not affected by the advisory.

The advisory will continue until bacteria levels fall below the accepted health level.

Waters with elevated bacteria levels can pose significant health risks, potentially leading to gastrointestinal illness and other diseases, according to the department. Anyone who comes into contact with the affected waterway should wash thoroughly, especially before eating or drinking.

DOH-Okaloosa said children and older adults, as well as people with weakened immune systems, are particularly vulnerable to disease, so every precaution should be taken if in contact with the affected waters.

The advisory follows an environmental incident in Cinco Bayou that first came to light Sunday, Aug. 2. Okaloosa County staff, the City of Fort Walton Beach and the Department of Health began an on-site investigation that day into an abnormal discoloration and odor in the bayou between Beal Parkway and Eglin Parkway.

At the end of Tuesday’s Board of County Commissioners meeting, Okaloosa County Commissioner and Board Chairman Trey Goodwin described the incident as “a significant” event that impacted three and a half miles of the bayou within a 24-hour period, killing thousands of fish and crabs. He said the water turned gray and the odor was a sulfur-type smell that would burn the nose and eyes.

Goodwin said the source of the incident had not been identified and that multiple agencies were pursuing possible causes, including water and sewer systems and other point sources. He said water test results were expected to come in over several days, with different levels of analysis.

The DOH-Okaloosa advisory does not identify a cause of the environmental incident, and no agency has stated on the record what led to the elevated bacteria levels or the fish kill.

The department said it is performing water quality monitoring and testing. Once satisfactory results are achieved, the advisory will be lifted.