Water: Finding, Purifying & Storing the One Thing You Can't Survive Without

Cities are full of water. You just need to know where it’s hiding.

• Hot water heaters — Your single best urban water source. A standard residential tank holds 150–300 litres. Immediately after a disaster, shut off the intake valve to prevent contaminated mains water mixing in. Open the drain valve at the bottom to access clean, already-heated water. This alone can keep a family alive for a week.
• Toilet tanks (the back cistern, never the bowl) — 5–10 litres of clean water per tank, assuming no chemical cleaners like bleach tablets were in it. If the water has a blue or green tint, skip it.
• Pipes — Open the highest tap in a building to break the vacuum, then collect from the lowest tap. Gravity will drain remaining water from the plumbing.
• Swimming pools and spas — Contain chlorine and stabilisers. Use only after filtration through activated charcoal, then boil. Not ideal, but thousands of litres in an emergency.
• Rainwater collection — Any clean surface (tarps, bin lids, car bonnets) angled into a container. In urban areas, avoid collecting off roofing materials treated with chemicals for the first 10 minutes of rain (let the “first flush” rinse the surface), then collect.

• Follow animal trails downhill. Game trails that converge almost always lead to water. Listen for running water — sound carries further than you think in a quiet forest.
• Look for indicator plants: Cattails, willows, cottonwoods, and reeds all require roots in or near water. Green vegetation in an otherwise dry area is a signpost.
• Morning dew collection. Tie absorbent cloth around your ankles and walk through tall grass at dawn. Wring into a container. You can collect 500 ml–1 litre per hour in heavy dew.
• Dig in dry riverbeds. Find the outer bend of a dry creek — water pools deepest on the outside of curves. Dig 30–60 cm down. If the hole fills with muddy water, let it settle for an hour, then filter and purify.
• Transpiration bags. Tie a clear plastic bag around a leafy branch in direct sunlight. Condensation will collect inside — around 200–500 ml per day per bag. Use several. Avoid poisonous plants.

Water exists in deserts — it’s just hidden. Finding it is about reading the landscape.

• Dig at the outside bend of dry washes (same principle as riverbeds). Water collects below the surface where it was last flowing.
• Vegetation is your map. Cottonwoods, poplars, and willows mean water within 1–3 metres of the surface. Mesquite can reach water 15+ metres deep — if that’s the only green you see, you’ll need to dig seriously.
• Solar still. Dig a hole ~60 cm deep and 90 cm wide. Place a container in the centre. Cover the hole with a clear plastic sheet, seal the edges with sand/rocks, place a small stone in the centre so the sheet dips over the container. Condensation drips into the container. Yield: 300–700 ml per day. Add crushed green vegetation or even urine around (not in) the container to increase yield.
• Dew at dawn. Even deserts produce dew. Spread metal, glass, or plastic sheets before nightfall. Collect at first light. In some deserts this is the most reliable daily water source.
• Rock crevices and shaded overhangs often hold small pools after rare rains. Check anywhere shadows persist through the day.

• NEVER drink seawater. It contains ~35 g/L of salt. Your kidneys need more water to flush it than you took in. Drinking seawater accelerates dehydration and will kill you faster than drinking nothing.
• Dig behind the first dune line. Coastal areas often have a freshwater lens — a layer of fresh groundwater floating on denser saltwater. Dig 1–2 metres behind dunes. If the water tastes slightly brackish but not salty, it’s survivable. If salty, dig further inland.
• Rainwater is your primary source. Coastal areas often get more rain than inland. Maximise collection surfaces.
• Distillation. If you have fire and basic equipment (a pot, tubing/bamboo, and a collection vessel), you can boil seawater and collect the steam. The condensed steam is fresh water. Slow but reliable.

• Never eat snow directly. It drops your core temperature and costs your body more energy to melt internally than you gain in hydration. Always melt snow first — over fire, against your body (in a sealed container between clothing layers), or in sunlight.
• Old sea ice is safer than new sea ice. First-year sea ice is salty. Multi-year ice (bluish, rounded, smooth) has had salt leach out over time and is nearly fresh. Taste-test before committing.
• Prioritise ice over snow. Ice is denser — you get more water per volume and it melts faster.
• Black container trick: Put snow in a dark-coloured container in direct sunlight. Black absorbs heat — even weak winter sun can melt snow this way.

• Sealed containers are safe. Any water that was in a sealed bottle, tank, or covered well before fallout arrived is fine to drink.
• Avoid all open surface water in the fallout zone for at least 2 weeks (longer near the blast). Radioactive particles settle on surfaces — rivers, lakes, and puddles are contaminated.
• Deep well water is generally safe. Groundwater 3+ metres below the surface is naturally shielded. Wells with sealed covers are your best post-nuclear water source.
• Filtration helps but doesn’t eliminate radiation. Running water through soil, sand, and crushed charcoal removes most particulates (up to 90%+ reduction). This is better than nothing but not a guarantee. Combine with letting water settle for 24–48 hours, then decanting from the top — heavy particles sink.
• Boiling does NOT remove radioactive contamination. It concentrates it. Do not rely on boiling alone after nuclear events.

• Assume ALL surface water is contaminated. Floodwater contains sewage, agricultural chemicals, fuel, dead animals, and industrial waste. Even water that looks clear may be full of bacteria and parasites.
• Boil + filter + chemically treat. Use all three methods for floodwater. Filter first (cloth, then sand/charcoal if possible), then boil for 1–3 minutes, then add 2 drops of bleach per litre as an extra safeguard.
• Municipal water may be unsafe for weeks after flooding even when pressure returns. Broken mains allow contamination. If authorities haven’t declared it safe, treat it.

• Immediately shut off your water heater’s intake valve. This preserves the clean water already in the tank before contaminated mains water can mix in. This is the single most important thing to do for water in the first 60 seconds.
• Broken mains = contaminated supply. Even if water still flows from your tap after a quake, it may be mixed with sewage from cracked pipes underground. Treat all tap water.
• Drain plumbing from top to bottom (open highest tap, collect from lowest) before mains contamination works through the system.

• Volcanic ash makes water acidic and abrasive. It contains fine glass particles, sulphur compounds, and heavy metals. Don’t drink untreated ashfall-contaminated water.
• Filter through tightly woven cloth first (ash particles are very fine), then through crushed charcoal, then boil. Multiple cloth passes may be needed.
• Rainwater during or shortly after eruption is acidic. Let it sit, test if possible (pH strips), and neutralise with crushed limestone, chalk, or wood ash if available.
• Covered water sources are safe. Anything that was sealed before ashfall is fine.

Keeping Water Safe After You’ve Found It

• Use food-grade containers only. HDPE plastic (recycling number 2), PET (number 1), or glass. Never use old milk jugs — milk proteins are nearly impossible to fully remove and breed bacteria.
• Treat stored water. Add 2 drops of unscented bleach per litre before sealing. This keeps it safe for 6–12 months.
• Store in cool, dark conditions. Heat and sunlight degrade plastic and encourage algae growth. A basement or root cellar is ideal.
• Label everything. Date the container and note the source and whether it’s been purified. In a crisis, you will not remember.
• Pre-disaster target: 4 litres per person per day for at least 2 weeks. That’s 56 litres per person minimum. More if you live somewhere hot.
• Rotate stock. Commercial bottled water lasts 1–2 years. Home-treated water should be replaced every 6 months.

Improvised Containers (Post-Disaster)

If you don’t have proper containers:

• Plastic bags (doubled up) inside a box, backpack, or hole in the ground
• Lined pits — dig a hole, line with a tarp or plastic sheet, cover to keep debris out
• Sealed buckets from construction sites or restaurants (food-grade only — check the recycling symbol)
• Rain barrels — any large container under a downspout or gutter. Add a mesh screen to keep debris and mosquitoes out.

Handmade Containers — When You Have Nothing Left

If manufactured containers aren’t available, you can make your own. The quality of a handmade container determines whether your water stays safe or becomes a breeding ground for bacteria. Not all materials are equal.

Container Material Quality

📖 Related: For detailed instructions on brain tanning, smoke tanning, and hide preparation for waterskins, refer to the Leatherworking & Tanning guide (covers proper hide curing, waterproofing techniques, and container construction).