Salem-area residents heading to Pettit Reservoir for summer recreation should avoid swimming and any activity that risks swallowing water after the Oregon Health Authority escalated its warning for the Marion County lake on July 10.
OHA issued a recreational use health advisory citing elevated levels of microcystin, a toxin produced by cyanobacteria. The agency had already placed a lower-level health precaution on the reservoir on Wednesday, June 24, after a visible bloom appeared. Testing since then confirmed toxin levels high enough to pose a direct health risk.
The advisory carries specific warnings for families with children and dog owners. Children face greater risk because of their smaller size and tendency to swallow water while playing, according to OHA spokesperson Erica Heartquist.
Dogs can become extremely ill or die within minutes to hours of exposure by drinking contaminated water, licking their fur, or eating dried toxin crusts along the shoreline, according to OHA.
OHA recommends keeping dogs on leashes and away from the water at all times near the reservoir.
What's still safe
The advisory does not close the reservoir. OHA encourages visitors to keep enjoying Pettit Reservoir for fishing, camping, hiking, biking, picnicking, bird watching, canoeing, and kayaking. Boating remains safe as long as speeds stay low enough to avoid creating excessive water spray.
Anglers should note one caveat: OHA recommends against eating fish caught from bloom-affected areas. Those who choose to keep their catch should remove fat, skin, and organs before cooking, and rinse fillets with clean water.
Health risks to know
Symptoms of cyanotoxin exposure in people include stomach cramps, diarrhea, nausea, and vomiting. More serious cases can involve numbness, tingling, dizziness, and shortness of breath requiring medical attention.
In dogs, watch for difficulty walking, seizures, lethargy, and loss of appetite. Seek veterinary care immediately if symptoms appear.
One critical warning for campers: boiling, filtering, or treating water with camping-style filters will not remove cyanotoxins. Anyone drawing water directly from the reservoir for drinking or cooking should use an alternative source.
What happens next
The advisory remains in effect until follow-up testing confirms microcystin levels have dropped to safe thresholds. No re-test date has been announced. Residents can check OHA's Cyanobacteria Blooms page at oregon.gov/OHA for updates or call 971-673-0482 to report illness or ask health questions.
Pettit Reservoir, a Marion County lake popular for largemouth bass and bluegill fishing, draws paddlers, anglers, and hikers from across the Salem area during summer months.
