Bathing waters in the Central Bohemian Region in the 2026 season: 44 monitored sites, a bathing ban in Ostrá after cyanobacteria and chlorophyll rose to grade 5 — and not a single case of microbiological pollution or cercariae
On 22 September 2026 the Regional Public Health Authority of the Central Bohemian Region (KHS) published its assessment of the bathing season. Water quality at natural bathing sites was monitored according to the approved monitoring calendar from mid-May to the end of August 2026; throughout the season the weather was markedly warmer and sunnier than average, which according to KHS had no fundamental effect on water quality.
- In 2026, 44 sites were registered and regularly monitored: 23 bathing areas and natural bathing sites, checked on dates set in the monitoring calendar issued each year by the public health authority as a public notice, and 21 bathing reservoirs and facilities with natural water treatment, one of which did not operate this season. At 11 sites KHS itself carried out sampling and testing; elsewhere the operators performed the monitoring and passed the results to KHS for evaluation.
- At the Orlík and Slapy reservoirs water quality was very stable throughout the season. In August, at the Županovice and Živohošť bathing areas (Slapy reservoir), increased phytoplankton during extreme temperatures reduced transparency — grade 2 — and at Živohošť the cyanobacteria content also rose at the very end of the season — grade 3. At Orlík, lack of rainfall left the water level 15 m below normal at the end of August, making access to the water more difficult.
- Grade 2 due to increased chlorophyll was recorded, among others, at the Nový rybník pond in the Příbram district and at Vyžlovka, the Proboštská jezera lakes and Jureček (Prague-East district); at the Bakov sandpit (Mladá Boleslav district) — as every year — grade 3 from mid-July due to cyanobacteria and chlorophyll. The only significant deterioration concerned the Ostrá bathing site (Nymburk district): grade 4 in mid-season, grade 5 towards the end and a bathing ban issued by KHS.
- No microbiological pollution of bathing water and no cercariae were found at any monitored site this season. Because of low rainfall, the season did not start at all at the Pilský pond near Sedlec-Prčice. KHS published the assessment of each site on an ongoing basis on its website and on the koupacivody.cz portal.