Water When the Taps Stop

The tanker didn't come today. It's not coming tomorrow either; the roads are blocked and nobody's sure if the depot is even operational. Your overhead tank has maybe 200 litres left and there are five people in the house. You do the maths and it doesn't add up, because at normal usage it isn't enough.

Water is the first utility to fail in any crisis. Before power, before gas, before food supply chains. In Karachi, water is already fragile on a normal day: tanker-dependent neighbourhoods, low-pressure mains, contaminated lines. In a crisis, it goes from fragile to gone.

This guide covers how much you actually need, how to store it, how to purify what you have, and how to ration when you don't know when it's coming back.

How much you actually need

People overestimate how much water they use and underestimate how much they need. Here's the breakdown:

Drinking water

The minimum: 3 litres per person per day. That's for drinking only, not cooking, not washing, not flushing.

In a Karachi summer, when temperatures regularly exceed 35°C, push that to 4 litres per person. Dehydration accelerates dangerously in heat, especially for children and elderly family members.

Family of four (two adults, two kids): 10-14 litres per day for drinking alone.

Total water use

Drinking is only part of it. Here's where water actually goes in a household:

• Cooking: 2-4 litres per day (rice, dal, chai)
• Basic hygiene: 5-10 litres per day (hand washing, face washing, not showers)
• Flushing: 6-10 litres per flush. A family flushes 15-25 times a day. That's 90-250 litres just on toilets.

On a normal day, a family of four uses 300-500 litres. In crisis rationing, you need to cut that to 30-50 litres total. That's a 90% reduction. The flush is where you save the most.

What you have right now

Before a crisis hits, know your water inventory:

Overhead tank: Most Karachi homes have one. Capacity varies: 500 litres for a small apartment tank, 1,000+ litres for a house. Find out yours. Look at the manufacturer label on the tank, or measure it. This number matters.

At 30 litres per day (strict rationing), a 500-litre tank gives you roughly 16 days of water. At normal usage, it gives you 1-2 days. The difference between those numbers is entirely about discipline.

Water heater (geyser): Your geyser holds 25-50 litres of usable water. If the mains are cut, this is a reserve most people forget about. Turn off the power to it, open the drain tap at the bottom, and collect it in buckets.

Ice in the freezer: If power goes out, your freezer ice will melt. Collect it; it's clean water. A full freezer might give you 5-10 litres.

Hot water in pipes: There's water sitting in your plumbing right now. Open the lowest tap in your house and let gravity drain whatever's in the pipes into a container. It's not much, maybe 3-5 litres, but in a rationing situation, everything counts.

For more hidden household water sources, see the FCEmergency Water from Your Home Field Card.

First response

When you realise water supply is threatened (tanker not coming, mains cut, crisis declared), do these immediately:

1. Fill everything. Every pot, every bucket, every bottle. The bathtub if you have one (bathtubs hold 150-250 litres). Fill your overhead tank if mains are still running. Do this before the mains pressure drops to zero.
2. Start rationing immediately. Don't wait until the tank is half-empty. Start now. Switch to bucket flushing, stop showers, stop washing dishes with running water.
3. Separate drinking water. Designate specific clean containers for drinking water only. Don't cook with it, don't wash hands in it, don't let kids drink directly from the container (pour into glasses). Once drinking water is contaminated, you can't uncontaminate it without purification.
4. Track consumption. Mark your tank level or count your jerry cans. Check once a day. Know exactly how much you have and how fast it's going down.

Purification

If your stored water runs out and you need to use water from sources you don't trust (rain, open tanks, neighbourhood taps you're not sure about), you need to purify it.

Here are four methods, ranked by practicality:

1. Boiling: the most reliable method

A rolling boil for 1 minute kills virtually all pathogens. That's it: one minute of active boiling, not simmering.

• Works against bacteria, viruses, and parasites
• Requires fuel (sui gas, portable stove, fire)
• Doesn't remove chemicals or heavy metals
• Let it cool naturally. Don't add ice or cold water.

The downside: You need fuel. If sui gas is cut and you don't have a portable stove, boiling isn't an option. That's why the next methods exist.

For a step-by-step reference, see the FCBoiling Water for Safety Field Card.

2. Chlorine (bleach): cheap and effective

Regular household bleach, specifically unscented, plain sodium hypochlorite, purifies water. Not the scented kind, not the colour-safe kind. Plain bleach.

Dosage: 2 drops of bleach per litre of water. Stir. Wait 30 minutes. The water should have a faint chlorine smell after 30 minutes. If it doesn't, add 2 more drops and wait another 15 minutes.

• A single bottle of bleach can purify thousands of litres
• Costs almost nothing
• Available everywhere
• Works against bacteria and viruses
• Less effective against some parasites

Important: Check the bleach concentration. Standard household bleach in Pakistan is typically 3-5% sodium hypochlorite. If the concentration is different, the dosage changes. 2 drops per litre is for standard household bleach.

For the exact process, see the FCWater Purification with Bleach Field Card.

3. Aquatabs and purification tablets

Available from pharmacies and outdoor stores. Aquatabs are the most common brand.

• One tablet typically treats 1-5 litres (check packaging)
• Wait 30 minutes after dissolving
• Pack of 50 tablets: Rs. 300-500
• Extremely portable: keep a strip in every grab bag
• Effective against bacteria, viruses, most parasites

These are the easiest option for water purification on the move. If you're evacuating and need to use water from unknown sources along the way, Aquatabs are what you want.

4. SODIS: when you have nothing else

Solar Water Disinfection. It's slow but it works and needs zero supplies except a clear plastic bottle and sunlight.

• Fill a clear PET bottle (like a disposable mineral water bottle) with water
• The water must be relatively clear. If it's muddy, let it settle first and pour off the clear part.
• Lay the bottle on its side in direct sunlight
• Wait 6 hours in full sun. If it's cloudy, wait a full day.
• UV-A radiation from the sun kills bacteria and viruses

Limitations: Doesn't work for heavily contaminated or chemically polluted water. Doesn't remove sediment. Slow. But when you have no fuel, no bleach, and no tablets, this works.

For the full process, see the FCSolar Water Disinfection Field Card.

Storage

How you store water matters as much as how much you have.

Containers

• Food-grade jerry cans: 20-litre blue or white HDPE jerry cans from hardware stores. Rs. 300-800 each. These are purpose-built for water storage. Buy 3-4 and keep them filled.
• Steel containers: Clean steel dabbas or pots with lids. Good for smaller quantities of drinking water.
• PET bottles: Clean, empty mineral water bottles. Free. Good for portable drinking water.
• Don't use: Old paint buckets, chemical containers, or anything that previously held non-food liquids. The plastic absorbs chemicals and leaches them into water.

Keeping it clean

• Seal containers. Every container should have a lid or cover. Open water collects dust, insects, and bacteria within hours.
• Don't dip hands in. Pour water from containers, don't reach in with cups or hands. Your hands introduce bacteria.
• Rotate stored water every 3 months. Even sealed water goes stale. Use it for cooking or cleaning, refill with fresh.
• Keep in shade. Direct sunlight on a plastic container accelerates chemical leaching from the plastic. Store in a cool, dark spot.

How much to store

Minimum recommendation: 10 litres per person as a permanent reserve. Family of four = 40 litres. That's two jerry cans. Keep them filled, keep them sealed, check them quarterly.

Better: 20 litres per person, or 80 litres for a family. Four jerry cans. This gives you 5-7 days of drinking water at strict rationing, buying time for the situation to resolve or for you to find more.

Rationing protocol

When you don't know how long the disruption will last:

Days 1-2: Moderate conservation

• Normal drinking: stay hydrated
• Bucket flushing only
• No showers: wet cloth wipe-down if needed
• Minimal cooking water: one-pot meals

Days 3-5: Active rationing

• Measured drinking: each person gets a set daily amount poured into their own bottle
• Cooking with minimum water: sattu and no-cook meals over rice and dal
• Bucket flush only for solids
• Hand sanitizer instead of hand washing where possible

Days 5+: Strict survival

• Drinking and basic cooking only
• Track every litre
• Investigate alternative sources: rainwater collection, neighbours, neighbourhood mosque tap, building sump pump
• Consider whether moving to a location with better water access is viable

Dehydration

Recognising dehydration matters, especially in children and elderly family members, who may not feel thirsty or may not communicate that they're struggling.

Signs in adults:

• Dark yellow or amber urine
• Dry mouth, cracked lips
• Headache, dizziness
• Fatigue, irritability

Signs in children:

• No tears when crying
• Dry nappies for 3+ hours in infants
• Sunken eyes
• Unusual lethargy or fussiness

Signs in elderly:

• Confusion (can be mistaken for other conditions)
• Rapid heartbeat
• Low blood pressure when standing

If someone is dehydrated: small, frequent sips of water with ORS (oral rehydration salts). Not large gulps; the stomach will reject large amounts. ORS sachets are available at every pharmacy for Rs. 10-15 each. Stock a dozen.

If you don't have ORS, you can make it: 1 litre clean water + 6 level teaspoons sugar + half a level teaspoon salt. It should taste like tears. See the FCORS from Scratch Field Card for exact measurements.

Tonight

1. Check your tank. How many litres does your overhead tank hold? If you don't know, find out this week.
2. Buy 2 jerry cans. 20-litre food-grade ones from a hardware store. Fill them. Store them. That's 40 litres of emergency water for under Rs. 1,500.
3. Buy bleach. One bottle of unscented household bleach. Rs. 100. Write "2 drops per litre, wait 30 min" on it in marker.
4. Buy Aquatabs. One strip from the pharmacy. Rs. 300. Put them in your grab bag.
5. Find your geyser drain. Know where it is and how to open it before you need to.

Water is the one thing you can't improvise and can't go without. Everything else in preparedness is secondary to this. Sort it tonight.