One thing that humans cannot live without is water. On a normal day we can turn on the tap and fill our glass over and over. When disaster strikes, we will have to rely on what we have stored or can find. If public utilities are out, then municipal water or the electricity to pump water from your well will not be an option. Depending on the disaster, sources like rivers and lakes might be too dangerous or polluted to drink from. Flood waters can pick up many types of pollutants. Rainwater might also be contaminated in cases such as a nuclear explosion or a volcanic event. Given this, you may need to look for less obvious locations.
Some locations that may have clean water (Though treating or boiling might still be needed)
Water heater – Every home or business has one and they can be as large as 100 gallons
Garden hose – This might not be a huge amount, but you might find upwards of a gallon just sitting in the hose from its last use.
Toilet tank – While it seems unsanitary, the water in the back tank of a standard consumer toilet is clean. Just be sure that it does not have a toilet cleaner tablet in it. These contain more than just bleach and can poison you.
Silcock connection- The faucet found on the outside of commercial buildings needs a silcock key to open properly, but due to its low location on the building, it should gravity feed out whatever is left in the building’s pipes.
Retention Ponds – Most housing and retail developments are required to have a retention pond to capture run off water. Some larger ones are even stocked with fish to combat mosquito breeding. It is suggested you filter this water because it could have contaminants picked up as it drained from yards or the pavement.
With water being one of the most vital keys to survival it might become the most important item to resupply. In a true disaster stocks of bottled fresh water will disappear quickly. It will be your responsibility to find places to supply yourself and your family or group. As stated before, thinking creatively will be the key to finding what others overlook.