Safe water in Slovenia: notices, drought and what to store

Short answer. Slovenia's drinking water is monitored on supply systems serving 50 or more people, which covers 94% of the population ¹. Phaenyx found no national register of boil-water orders: expect them locally. If one is issued, the National Institute of Public Health (NIJZ) advises boiling water for three minutes and using it within 24 hours ². Store at least 7.5 litres per person per day, for at least three days ³.

How do I know if my tap water is unsafe?

Since 2004, drinking water has been monitored on supply systems or supply areas serving 50 or more people, and on all smaller ones that supply public buildings; 94% of the population is covered ¹. NIJZ says large and medium systems generally have good-quality water and proper management, while faecal contamination occurs in places in small systems serving up to 500 people, some of which lack protection zones, proper management or treatment ¹. NIJZ publishes annual national drinking-water reports ¹.

Phaenyx found no national register of boil-water orders ("prekuhavanje vode") for Slovenia. Expect the notice from your water supplier or municipality, and keep their contact details with your emergency papers. How official warnings reach you is explained on our Slovenia alerts page.

What does NIJZ say to do during a boil-water order?

NIJZ calls boiling a short-term, urgent measure to make water microbiologically safe ²:

• boil in a clean pot washed with detergent and water;
• once the water boils, a vigorous boil of one minute is usually enough, but NIJZ recommends three minutes for safety, which also makes the water safe for people with a severely weakened immune system;
• if the water is cloudy, let it settle and filter it through several layers of clean cloth or a paper coffee filter before boiling;
• keep it in the same pot, covered, in the fridge, and use it for drinking and cooking within 24 hours, exceptionally 48 hours ².

See also What to do during a boil-water notice and Do-not-drink notices.

How much water should I store?

At least 7.5 litres of drinking water per person per day, for drinking, cooking and basic hygiene, with a stock for at least three days ³. After two to three days, needs rise to at least 20 litres per person per day, exceptionally 15 ³. For a household of three, the three-day minimum is 67.5 litres. Check stocks twice a year, when the clocks change ³. Details are on our Slovenia emergency supplies page; see also Water storage containers.

Is Slovenia short of water?

In WRI's Aqueduct 4.0 model, the population-weighted median of Slovenian cities is in the "low" category for water stress today, "low to medium" in the 2050 business-as-usual projection, and "medium" for drought risk on a separate WRI scale ⁶. These are city medians: a given town can sit higher or lower.

The Environment Agency (ARSO) tracks agricultural drought in a drought bulletin ("Sušomer") on its agrometeorology pages ⁴. Phaenyx found no national page listing current water-use restrictions. See Drought preparedness.

What about private wells and rainwater tanks?

If you have your own well or another source supplying fewer than 50 people, NIJZ says you are responsible for it yourself: routine monitoring covers only systems supplying more than 50 people. Your local community will tell you this and advise you on possible measures, and you can ask the nearest public health institute (zavod za zdravstveno varstvo) for advice ⁷. For rainwater tanks ("kapnice"), NIJZ advises not using them during and after a fire, and, before it rains, diverting water from catchment surfaces soiled by the fire away from the tank, so the first rain rinses them without reaching it ⁵. If a private supply may be contaminated, see Private well emergencies and Water safety after a flood.

A household plan can keep your water stock, supplier contacts and warning channels in one place.

Frequently asked questions

How long should I boil tap water in Slovenia?

Three minutes of vigorous boiling, as NIJZ recommends ².

How long does boiled water keep?

24 hours in a covered container in the fridge, exceptionally 48 hours ².

How much water for three days?

At least 22.5 litres per person (7.5 litres a day) ³.

Who checks a private well?

You do: NIJZ says owners are responsible for supplies serving fewer than 50 people, which are outside routine monitoring ⁷.

Can I drink from my rainwater tank after a fire?

No. NIJZ advises not to use rainwater tanks during and after a fire ⁵.

Sources

1. Nacionalni inštitut za javno zdravje (NIJZ) — Pitna voda — https://nijz.si/moje-okolje/pitna-voda/ (accessed 2026-10-27)
2. Nacionalni inštitut za javno zdravje (NIJZ) — Navodila o prekuhavanju vode — https://nijz.si/moje-okolje/pitna-voda/navodila-o-prekuhavanju-vode/ (accessed 2026-10-27)
3. GOV.SI / Uprava RS za zaščito in reševanje (URSZR) — Bodite pripravljeni ob nesrečah — https://www.gov.si/teme/bodite-pripravljeni-ob-nesrecah/ (accessed 2026-10-27)
4. Agencija RS za okolje (ARSO) — Agrometeorologija (Sušomer – sušni bilten) — https://meteo.arso.gov.si/met/sl/agromet/ (accessed 2026-10-27)
5. Nacionalni inštitut za javno zdravje (NIJZ) — Napotki prebivalcem ob izpostavljenosti dimu požara — https://nijz.si/moje-okolje/zrak/napotki-prebivalcem-ob-izpostavljenosti-dimu-pozara/ (accessed 2026-10-27)
6. World Resources Institute (WRI) — Aqueduct 4.0 (water stress, 2050 projection and drought risk) — https://www.wri.org/aqueduct (accessed 2026-10-27)
7. Nacionalni inštitut za javno zdravje (NIJZ) — Pogosta vprašanja o pitni vodi — https://nijz.si/moje-okolje/pitna-voda/pogosta-vprasanja-o-pitni-vodi/ (accessed 2026-10-27)