Water Outages and Contaminated Water
You can manage for days without power and for weeks with little food. Without safe water you have about three days. Tap water can stop after a burst main, a long blackout that stops the pumps, a flood or a contamination alert. The preparation is simple: store water, and know how to make more of it safe.
1. Before: store water
- Store at least 3 litres of drinking water per person per day. For one week, that is about 21 litres per person. Use the kit calculator for your household.
- Use sealed bottled water or clean food-grade containers with tight lids.
- Store in a cool, dark place. Replace tap water you bottled yourself every 6 months.
- Keep a way to treat water: a camping stove to boil it, purification tablets or a filter.
- Keep clean buckets or jerrycans with lids to collect water from a distribution point.
- Know where your home's main water valve is.
2. During: if the tap stops or water is unsafe
- Follow your water company and municipality. A boil water notice means the water may contain germs. A do not drink or do not use notice means boiling will not help: use bottled water.
- Use stored and bottled water first for drinking, cooking, brushing teeth and baby formula.
- Fill clean containers as soon as an outage is announced.
- Authorities usually set up water distribution points. Bring your own containers.
Making water safe to drink
- Boiling is the most reliable method. Bring clear water to a rolling boil for 1 minute, then let it cool and store it in clean, covered containers. Above 2,000 metres (6,500 feet), boil for 3 minutes.
- If the water is cloudy, let it settle and filter it through a clean cloth, paper towel or coffee filter first.
- If you cannot boil, use water purification tablets and follow the instructions on the pack.
- As a last resort, unscented household bleach (5 to 9% sodium hypochlorite) can disinfect clear water: 2 drops per litre, stir and wait at least 30 minutes. Double the amount if the water is cloudy or very cold.
- Boiling and disinfecting kill germs. They do not make water safe if it contains fuel or toxic chemicals. If the water smells of chemicals, do not drink it.
Hygiene and toilets
- Use hand sanitiser and wet wipes to save water.
- You can flush a toilet by pouring a bucket of any water into the bowl, as long as the sewers work.
- If sewers are not working, use a bucket lined with strong bags, with cat litter or sawdust. Tie and store the bags outside.
- Rainwater and melted snow are fine for flushing and washing floors, not for drinking untreated.
3. After: when the water returns
- Wait for the official all-clear before drinking tap water again.
- Run the cold taps for a few minutes until the water is clear.
- Throw away ice and drinks made with tap water during the notice.
- Refill your stored water.
Quick checklist
- 3 litres per person per day stored
- Clean containers with lids
- Camping stove or purification tablets
- Hand sanitiser and wet wipes
- Bucket, strong bags and cat litter
- Main water valve located
Frequently asked questions
How long can stored water be kept?
Factory-sealed bottled water keeps until the date on the bottle. Tap water you bottle yourself should be replaced about every 6 months.
Can I drink water from the water heater?
In an emergency, the water in a hot water tank can be used if it was clean when it entered. Turn off the power or gas to the heater first and let it cool.
See also Home kit for 7 days, Power Outages, Floods and all risks.
Sources
- CDC: How to make water safe in an emergency
- FEMA / Ready.gov: Water
- DSB Norway: Egenberedskap (PDF, Norwegian)
Educational material. Always follow instructions from your water company and local authorities. Last reviewed: November 2026.