Are Lakes Really Safe for Swimming?
Summer just isn’t complete without a trip to the lake. Keep in mind, though, that while lakes can look calm and inviting, they aren’t the same as chlorinated pools. Under the surface, a lot is going on that could make you think twice before running headfirst.
The short answer to “Are lakes safe for swimming?” is sometimes. There are plenty of days when the water is fine and the biggest thing you’ll deal with is a minnow brushing your ankle. But there are also days when bacteria, algae, or hidden hazards can make swimming a bad idea. The trick is knowing what you’re getting into before you get in.
Hidden Hazards of Lake Water
Unlike pools, lakes don’t get regular doses of disinfectant. That means bacteria, parasites, fungi, and viruses can stick around. The Centers for Disease Control and Prevention warns about fecal contamination from animal waste or untreated sewage, which can cause illness if swallowed or if it gets into a cut. This is especially true for lakes, because their still water holds pollutants longer than rivers or oceans.
One rare but scary risk is Naegleria fowleri, known as the brain-eating amoeba. While it’s highly uncommon in the U.S., it can be fatal if it enters the brain. Between 1962 and 2023, there were only 164 known cases in the country. Still, rare doesn’t mean impossible, so staying cautious is a smart move.
How Pollution Plays a Role
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The Great Lakes are summer playgrounds for millions, but water quality reports show a mixed picture. In 2024, 71% of tested Great Lakes beaches were unsafe for swimming at least one day. For Lake Michigan’s Illinois beaches, it was every single one of them. Along Lake Superior, nearly half of the tested beaches had at least one unsafe day.
Pollution often comes from sewage overflows, leaky septic systems, and runoff after storms. That’s why it’s recommended to check local water advisories before heading out.
Safety Starts Before You Get Wet
A lot of lake safety comes down to common sense. If the water is cloudy, smells bad, or has strange discoloration, it’s a red flag. Avoid swimming after heavy rain, because runoff can carry bacteria straight into the lake. Keep an eye out for pipes emptying into the water. And if you have an open wound or you just got a fresh tattoo or piercing, it’s best to skip the swim altogether.
Lakes also have physical hazards that pools just don’t. Sudden drop-offs and hidden rocks can trip you up. Not to mention underwater plants. Currents can surprise you even in seemingly calm water. Plus, with motorized boats around, visibility can be poor, so you could get separated from your group.
Gear and a Game Plan
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A U.S. Coast Guard-approved life jacket isn’t just for people who “can’t swim.” Even strong swimmers can get tired in open water, and bright life jackets make kids easier to spot. Swim skills are just as necessary. Lessons from a young age help build muscle memory and confidence, which can make a big difference in an emergency.
If you’re with kids or teens, set clear boundaries about where they can swim and stick to the buddy system. Go over what to do if someone gets into trouble, and make sure they know how to help without putting themselves at risk. And don’t forget basic comfort and safety: sunscreen, water breaks, and avoiding swimming right after a big meal all make for a better day.
So, Are Lakes Really Safe for Swimming?
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Sometimes, they are, and sometimes, they’re basically nature’s soup of bacteria and mystery floaties. The trick is treating every swim like it could either be the best day of your summer or the day you end up Googling “why does my skin itch after lake water?”
Be on guard and take all the precautionary measures. That way, the scariest thing you’ll face this summer might be explaining to your friends why you screamed like a horror movie extra when a patch of harmless lake weed brushed against your leg.