Earth Risk Watch / Western Australia reference pack

Water and heat: a calm household plan

Checked 5 August 2026. This guide is for preparing before an interruption, heatwave, fire or flood. In an active event, official instructions win: use Emergency WA, your water supplier, WA Health and DFES.

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Start with stored water

Build a buffer slowly, without panic buying

Daily minimum2.5 litres per person for drinkingHealthyWA's minimum drinking figure. Account for babies, older people, illness, pets, heat and prescribed needs individually.

Practical planning figureAbout 20 litres per person per dayHealthyWA's average for drinking, basic cooking and washing. Treat this as a planning estimate, not a reason to fill every space at once.

First milestone5 to 7 days of household basicsDFES uses this as a preparedness baseline. Add gradually as budget and storage allow; rotate supplies and keep containers clean and covered.

Use food-grade containers, label the fill date, keep them cool and protected from contamination, and rotate stored water. This page does not replace personal medical advice or local water-supplier notices.

Decision tree

What kind of water problem is it?

Mains water declared safeUse it normally.Do not create a treatment routine when your water supplier says the supply is safe.

Boil-water / microbiological noticeUse stored, bottled, or correctly treated water.For clear water, bring it to a rolling boil for one minute, cool it, then store it in clean covered containers. Alternatively use a drinking-water treatment product exactly as its label and health authority advise.

Cloudy waterClear it first; then treat it.Let it settle or pass it through a clean cloth, paper towel or coffee filter, then treat the clearer water. Filtering alone is not a general guarantee of safe drinking water.

Fuel, chemicals or radiation suspectedDo not boil it, filter it, or add tablets.Those methods do not make this contamination safe. Use a verified alternate source and follow health-authority instructions.

Important: a portable filter is not a universal purifier. Many do not remove viruses and some do not remove bacteria. Seawater also needs specialist desalination or distillation; an ordinary emergency filter does not make it drinkable.

Equipment and source choices

Buy capability, not promises

Useful basics: stored potable water, food-grade containers, a way to boil water safely, and a water-treatment product with current drinking-water directions.
Filters: choose only for the organisms the maker states it removes; consider it one step in a treatment process, not proof against every hazard.
Rainwater, tanks, bores and dams: may be valuable local sources but are not automatically safe. Their use after a fire, flood or contamination event needs source-specific advice from your supplier or local authority.
Never improvise chemical doses: concentrations and products vary. Follow the current official guidance and product label.

Heat days

Reduce heat strain before the hottest hours

Pick a cool place nowIdentify the coolest room at home and a nearby air-conditioned public place. Close blinds early; use fans safely; do not wait until symptoms start.

Protect people, food and medicinesCheck on people at higher risk, keep medicines as their labels require, and have a plan for refrigerated food if power is interrupted.

Use warnings, not a generic calendarBOM forecasts and warnings, Emergency WA and local health advice determine today's action. Avoid outdoor exertion in the hottest part of the day when official advice says conditions are dangerous.

Official sources and maintenance

Verify locally

HealthyWA: emergency treatment of drinking-water supplies - water quantities, storage and treatment guidance.
CDC: how to make water safe in an emergency - clear treatment limits and filter guidance.
DFES: prepare for a flood and Emergency WA warnings.
BOM climate outlooks - use the current outlook, not a fixed seasonal prediction on this page.

Publishing rule: an individual can maintain a country pack, but any local dosing, medical, evacuation or shelter instruction needs an official source URL, a checked date, local emergency links and a second reviewer before publication. Mark stale material clearly or remove it.

Public awareness guide, not an official warning system. Call 000 for life-threatening emergencies.