Safe water in the Czech Republic: notices, drought and what to store

Short answer. Most people in the Czech Republic drink water from public supplies: 94% in 2015, according to the SZÚ ¹. When it is unsafe, the water operator and the regional hygiene station (krajská hygienická stanice) decide what to do, which can include an order to boil water ¹. Phaenyx found no national list of these notices. The Interior Ministry's 72 hodin campaign sets 2 litres of drinking water per adult per day as the emergency minimum ².

How do I know if my tap water is unsafe?

The operator of a public water supply is responsible for its quality ¹. If water no longer meets the requirements, or there is good reason to suspect it does not, the operator and the regional hygiene station assess the risk and choose the measure: interrupting supply, flushing the network, disinfection, or a recommendation or order to limit how the water is used, including boiling it ¹. Respect a boil-water order until it is withdrawn ¹.

Phaenyx found no national portal listing boil-water or do-not-drink notices in the Czech Republic: they come from your operator and your regional hygiene station. Keep their contacts with your household plan, and see our Czech alerts page for the national warning signal.

Under a boil-water order, the SZÚ says to boil all water used for drinking, cooking, preparing drinks and food (especially fruit and vegetables), brushing teeth and cleaning open wounds ¹. Bring the water to a full rolling boil once, then let it stand for at least 10 minutes and cool naturally ¹. Tap water can still be used without restriction for washing, flushing toilets and other sanitary purposes ¹. See What to do during a boil-water notice and Do-not-drink notices.

How much water should I store?

At least 2 litres of drinking water per adult per day: "Nouzově si dospělý člověk vystačí se dvěma litry vody denně" (in an emergency an adult can manage on two litres a day) ². The campaign asks households to prepare for 72 hours and lists canisters or other sealable containers for water ². Full figures are on our Czech emergency supplies page; for storage, see How much water to store per person per day? and Water storage containers.

Is the Czech Republic short of water?

Drought is the bigger risk. In WRI's Aqueduct 4.0 model, the population-weighted median of Czech cities falls in the "low to medium" category for current water stress, rises to "medium to high" in the 2050 business-as-usual projection, and is "medium to high" for drought risk ⁴. These are city medians: a given town or river basin can sit higher or lower.

To follow conditions, the Czech Hydrometeorological Institute (ČHMÚ) assesses and forecasts hydrological drought every week and issues warnings for drought in surface water, in groundwater, or in both ³. Its map colours each administrative district (ORP): green for no drought expected, yellow for drought in surface or groundwater, orange for drought in both ³. For household steps, see Drought preparedness.

What if I have a private well?

About 5% of the population is permanently supplied from household or public wells ⁵. The owner of a private well is responsible for its water quality ¹. No regulation requires a household-only well to be tested, and nobody will do it for you; the SZÚ says every well owner should still have the water checked from time to time, because water can look and taste fine and still be unsafe ⁶. Ask a local hygiene or water laboratory how to take the sample ⁶. See Private well emergencies.

What should I do after a flood?

The SZÚ publishes a guide for the public on caring for a well after a flood ⁵. For tap water, follow your operator's instructions ¹, and see Water safety after a flood. A household plan can keep your water stock, operator contacts and the drought map in one place.

Frequently asked questions

Who orders a boil-water notice in the Czech Republic?

The water supply operator and the regional hygiene station, after assessing the risk ¹.

How long should I boil the water?

Bring it to a full rolling boil once, then let it stand for at least 10 minutes and cool naturally ¹.

Can I shower during a boil-water order?

Yes for most people: tap water can be used for washing and sanitary purposes ¹. Use boiled, cooled water for small children and people with weakened immunity ¹.

What should I do when the order is lifted?

Run the cold tap for one to five minutes until the water stays cold, and clean tap aerators, ice makers and home filters ¹.

Sources

1. Státní zdravotní ústav (SZÚ, National Institute of Public Health) — Informace pro veřejnost: převařování pitné vody (16 Dec. 2015) — https://szu.gov.cz/wp-content/uploads/2023/02/prevarovani_vody_verejnost.pdf (accessed 2026-10-27)
2. Ministerstvo vnitra ČR (Ministry of the Interior) — 72 hodin — Nouzové zásoby — https://www.72h.gov.cz/cs/nouzove-zasoby (accessed 2026-10-27)
3. Český hydrometeorologický ústav (ČHMÚ) — Hydrologické sucho — https://www.chmi.cz/predpoved-pocasi/rizika/hydrologicke-sucho (accessed 2026-10-27)
4. World Resources Institute (WRI) — Aqueduct 4.0 (water stress, 2050 projection and drought risk) — https://www.wri.org/aqueduct (accessed 2026-10-27)
5. Státní zdravotní ústav (SZÚ) — Studny — https://szu.gov.cz/tema/zivotni-prostredi/kvalita-vody/studny/ (accessed 2026-10-27)
6. Státní zdravotní ústav (SZÚ) — Vlastní studna: výhoda i riziko — https://szu.gov.cz/wp-content/uploads/2023/02/1vla_stu.pdf (accessed 2026-10-27)