Water supply disruption through failure or contamination, while unlikely, could result in economic losses for reliant industries and public health risk.
Water supply contamination or disruption may occur as a result of another event such as ashfall from a volcanic eruption. In a disaster the water coming out of the water main may not be safe. Garden chemicals, detergents, oils, road dust, dirt and possibly volcanic ash, can contaminate urban streams.
A supply of stored water is absolutely essential. During a disaster it is essential that hygiene standards are maintained. Health risks may be increased with disruption of normal water supplies.
Storing water before the emergency will ensure that you have a supply of safe water on hand. You can purchase bottled water or prepare your own containers of water. Purchase food-grade water storage containers from camping or hardware stores or recycle plastic soft drink bottles. Do not use milk containers, as protein cannot be adequately removed with washing, and may harbour bacteria.
You can also fill plastic ice cream containers with water, cover, label and keep in the freezer. These can help keep food cool if the power is off and can also be used for drinking.
Your hot water cylinder and toilet cistern are valuable sources of water. Check that your hot water cylinder and header tank are well secured. Do not put chemical cleaners in the cistern if you want to use the water.
You need at least three litres of drinking water for each person each day (make sure you have at least nine litres of water for every person) - preferably more. You will also need water for washing, cooking and pets.
Instructions for safely storing water
- Wash bottles thoroughly in hot water
- Fill each bottle until it overflows so no air is trapped
- Label each bottle with dates showing when the bottles were filled and when they need to be refilled
- Store bottles away from direct sunlight in a cool dark place
- Replace it at least every 6 months.
If the water comes from an untreated source (eg rain water) or you need to store water for up to 12 months, five drops of plain household bleach per litre of water can be added. The bleach must not contain fragrances or detergent. Do not drink for at least 30 minutes after disinfecting.
It is not safe to use bleaches that contain added scent or perfume, surfactants, detergents or other additives - they can make people sick. Surfactants will make the water foam or bubble when it is shaken or mixed.Bleaches with these additives are difficult to identify because cleaning product manufacturers aren't required to list ingredients. If the product's label is not clear about what has been added to the bleach, do not use the product for the safe storage of water.
Janola, one of the most well-known bleach brands, shouldn't be used.
Alternatives that manufacturers have advised can be used include:
- Budget Bleach Regular and Budget Bleach Extra Strength, but Budget Bleach Lemon shouldn't be used because it contains lemon fragrance
- Clor-o-Gene bleach.
Water purification tablets from chemists, tramping shops etc, can be used instead of bleach to chlorinate and make it safe to drink.
Water that is chemically contaminated is not able to be made safe to drink.
Your hot water cylinder can be your best supply of drinking water in a disaster. Water will still come out of your cylinder until your header tank is empty (if you have one). Turn off your water main, gas and/or electricity supply. Disconnect the pipe going into the top of the cylinder and siphon out the rest of the water with a garden hose. The sludge at the bottom of the cylinder is not safe to drink.
Toilet cisterns have water in them that is safe to drink provided that it does not have a chemical cleaner in it.
Disconnect the drain pipe to collect rain water off the roof or place clean containers outside to catch rain. This water may be contaminated. Treat it before you drink it. Don't drink water off a roof painted with lead based paint. If volcanic ash is present, listen to the radio for instructions about roofs and rainwater.
Many swimming pools are treated with chemicals that are dangerous to drink, however, this water could be used for washing.
Streams, ponds and lakes
Streams in towns may have a variety of contaminants in them. If there are obvious contaminants in the water, it is best not to use this source. If you do choose to use this water, boil it first in a container which will not be used for cooking.