Slovak sanitary doctors have updated information about the water quality at the country's bathing spots. Six locations received the strictest verdict: the water there is not suitable for swimming and is a serious danger to health. Before you load towels and swimsuits into your car, check the latest list.
Checks as of July 23, 2026, were carried out by the Public Health Authority (ÚVZ SR), an office that monitors over 160 artificial and natural bodies of water across the country, reports TASR. 164 artificial swimming pools with 482 pools had permission to operate. However, the situation with natural bodies of water is more complicated.
Where you cannot swim at all
Hygienists have declared six bodies of water dangerous for everyone without exception. There are two reasons: bacterial contamination and water "blooming."
Intestinal enterococci, an indicator of fecal contamination capable of causing infectious diseases, were detected at the Ružín reservoir near the SKI location and at VN Lipovina – Bátovce. Vinianske jazero is a separate story: a sample from July 21 showed exceeded enterococci limits, so doctors ordered a repeat collection.
Cyanobacteria, also known as blue-green algae, along with exceeded chlorophyll-a levels, were found:
- at Štrkovisko Čaňa;
- in the Gazárka recreation area in Šaštín-Stráže, where, according to Záhorí.sk, laboratory tests showed exceedances for both indicators;
- at Plážové kúpalisko JAZERO in Košice.
Increased risk: who should be careful
Seven more bodies of water are not officially closed, but the water quality there has worsened. Hygienists warn of risks for vulnerable groups: small children, pregnant women, allergy sufferers, and people with weakened immune systems. If someone in your family falls into this category, it is best to stay away from these locations:
- VN Duchonka, Jazero Malé Leváre, Plavecký Štvrtok, and Kaňianka — due to cyanobacteria;
- Ružín (Počkaj Beach), Delňa, and Kunovská priehrada in Sobotište — due to exceeded chlorophyll-a levels.
At the same time, there is good news from Záhorie: the water at Oširíd near Sekule and at Adamovské jazerá in Gbely is completely suitable for recreation according to the latest samples.
What are the practical dangers?
Cyanobacteria can produce toxins. Contact with such water causes skin and eye irritation and allergic reactions. If you swallow the water, it can also cause digestive problems: nausea, stomach pain, and diarrhea. Children, who splash most actively in the water and inevitably swallow it, suffer the most.
Intestinal enterococci are in a different category: they signal fecal contamination and can lead to infectious diseases. Therefore, the warning "water is unsuitable" is not just a formality.
How to check your lake before your trip
ÚVZ SR has launched an interactive water quality map, where information about officially tested bodies of water is updated daily. Water conditions change quickly in hot weather: what was clean a week ago can "bloom" in a few days, so check the map on the day of your trip. Detailed weekly reports are also published on the website of ÚVZ SR.
One final clarification. At several bodies of water (Izra, Krpáčovo Horná Lehota, Tajch Nová Baňa, Veľké Uherce, and Zelená voda – Kurinec), hygienists recorded reduced water clarity. It doesn't look very appealing, but it does not pose a direct threat to health: clarity is not a medically significant indicator. Murky water is not yet a reason to cancel your weekend by the lake.
