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

Short answer. In the UK, your water company is the best source of information when your supply is cut or unsafe, and it is the company that issues a notice telling you to boil your water ¹⁸. The government recommends keeping 3 litres of drinking water per person per day for 3 days ¹. Hosepipe bans are also decided by water companies ⁴.

How do I know if my tap water is unsafe?

Your water company tells you. Be Ready says the water company "is the best source of information" during a supply problem, and advises checking its website for service in your area ¹. A notice to boil water comes from your water company, or from your local authority if you are on a private supply ⁸; very occasionally, you may be told to stop using your water altogether ⁸. Phaenyx found no single national list of boil water or "do not drink" notices, so bookmark your water company's website now. The Drinking Water Inspectorate (DWI) lists the companies for England and Wales by region ³. In Scotland, Scottish Water shows the status of supply in your area; in Northern Ireland, NI Water gives supply information ¹.

If you are worried about your water, contact the company first. It can advise, test the water if necessary, and send you a free summary of water quality in your area on request. If you are not satisfied, the DWI can investigate on 0330 041 6501 ².

If a notice arrives, follow it to the letter. Our guides explain the difference: boil water notice and do-not-drink notice.

How much water should I store?

3 litres of drinking water per person per day, for 3 days ¹. That is 9 litres per person. Extra water may be needed for baby formula, medical devices and pets ¹. Be Ready calls bottled water "the safest way to prepare for water outages" ¹.

If you are eligible, sign up to your water company's Priority Services Register: during an outage, the company arranges alternative supplies for registered customers ¹. If someone in your home relies on a medical device that needs water, make a plan with the care team ¹. See the full UK emergency supplies list and how much water per person.

Is the UK short of water?

Not on average, but drought is a real risk. On the WRI Aqueduct 4.0 scale, the median UK city sits at "low to medium" baseline water stress today and in the 2050 business-as-usual projection, but at "medium to high" drought risk ⁶. These are medians across UK cities, not a figure for your street.

During a drought, water companies may impose Temporary Usage Bans (hosepipe bans): you then cannot use a hosepipe on the mains for things like watering the garden, filling a paddling pool or washing the car ⁴. Check your water company's website and local news for restrictions in force ⁴. The Environment Agency publishes monthly water situation reports and weekly rainfall and river flow reports for England ⁵. More in our drought preparedness guide.

What if my home has a private water supply?

About 1% of people in England and 3% in Wales use a private water supply, mostly in remote rural areas, from boreholes, springs or watercourses ⁷. Local authorities, not the DWI, regulate these supplies ⁷, and a boil water notice for a private supply comes from your local authority ⁸. In an emergency, see private wells in an emergency.

What should I do after a flood or an outage?

After an outage, discoloured water is common: run the cold tap nearest your stopcock for a while, and contact your water company if it does not clear ¹. During an outage, keep bottled water for drinking, handwashing and food preparation ¹. After a flood, read is my water safe after a flood? and what to do with no running water.

Frequently asked questions

Who issues boil water notices in the UK?

Your water company, or your local authority for a private supply ⁸. Contact your water company first about any water quality concern; the DWI investigates if you are not satisfied with the response ².

How much water does the UK government say to keep?

3 litres of drinking water per person per day for 3 days, plus extra for baby formula, medical devices and pets ¹.

Can I drink rainwater from a water butt?

No. Be Ready says not to drink it, as it could contain bacteria; use it for flushing toilets or watering plants ¹.

Who decides a hosepipe ban?

Water companies may enforce Temporary Usage Bans during a drought ⁴.

A household plan can record your water company, its notice page and your stored water in one place.

Sources

1. Cabinet Office (GOV.UK Be Ready) — Water supply interruptions or outages — https://beready.campaign.gov.uk/be-informed-about-hazards/water-supply-interruptions-or-outages/ (accessed 2026-10-27)
2. Drinking Water Inspectorate (DWI) — How to report a problem — https://www.dwi.gov.uk/consumers/how-to-report-a-problem/ (accessed 2026-10-27)
3. Drinking Water Inspectorate (DWI) — Find your local water company — https://www.dwi.gov.uk/consumers/find-your-local-water-company/ (accessed 2026-10-27)
4. Cabinet Office (GOV.UK Be Ready) — Droughts — https://beready.campaign.gov.uk/be-informed-about-hazards/droughts/ (accessed 2026-10-27)
5. Environment Agency — Water situation reports for England — https://www.gov.uk/government/collections/water-situation-reports-for-england (accessed 2026-10-27)
6. World Resources Institute (WRI) — Aqueduct 4.0 water risk atlas, median of UK cities (CC BY 4.0) — https://www.wri.org/aqueduct (accessed 2026-10-27)
7. Drinking Water Inspectorate (DWI) — What are Private supplies? — https://www.dwi.gov.uk/private-water-supplies/what-are-private-supplies/ (accessed 2026-10-27)
8. Drinking Water Inspectorate (DWI) — Receiving a Boil Water Notice — https://www.dwi.gov.uk/receiving-a-boil-water-notice/ (accessed 2026-10-27)