Water... you can't live long without it. When the tap water stops flowing you will need to know how to get clean drinking water and lots of it. How difficult this is will depend on where you are located. So lets look at where you will be getting your water from. You will need about 2 liters per person per day. More if you are physically exerting yourself or if the weather is very hot.
Almost any environment has water present to some degree. Deserts by their very nature will one of the hardest areas to obtain water from. So when the end of the world as we know it arrives deserts will be a place to avoid. On the other hand if you happen to be familiar with the desert environment and can secure your water supplies and food supplies there it will be one of the safest places on the planet because everyone else will be avoiding the desert like the plague.
One important consideration is when you do find good clean water you must collect as much of it as possible and never leave water until you have consumed as much of it as you can stand.
Heavy dew can provide water. Tie rags around
your ankles and walk through dew-covered grass before or shortly after sunrise. As the
rags or grass tufts absorb the dew, wring the water into a container.
Repeat the process until you have a supply of water or until the dew is
gone. You aren't going to meet all your water needs this way unless you spend a couple of hours at the task but later on you will see that it is well worth the effort.
Any water you find can be collected the same way as the dew. Just dip a cloth in the water and wring it out. This will be the first step in cleaning the water as you will collect less debris and trash doing this than if you simply dipped up the water. But scooping it up is fine.
Wherever you find banana or plantain trees, you can get water. Cut
down the tree, leaving about a 1 foot (.3 meters) tall stump, and scoop out the
center of the stump to form a bowl. The plant will pump the bowl with water. The banana tree will produce water for about 4 days.
Some vines can give you water. Cut the vine diagonally and it might yield a swallow of water. Not much but in a survival situation you take what you can get. And where there is one vine there is likely to be others.
Do not drink the liquid if it is sticky, milky, or bitter tasting.
If you happen to be in a tropical environment near or on the beach, coconuts of the green unripe version are the best for quenching your thirst. The milk from a ripe coconut is also suitable but it acts as a laxative so drink only in moderation.
Another method of collecting water is to get a plastic container such as a 2 liter coke bottle and fill it with the greenest most succulent leaves you can find. Seal the bottle and wait. It isn't much and the taste will be strong but not nasty. Not a long term solution but a good method when traveling or trying to establish a camp or home.
One method to purify water is to place a pool of water or large container of water below a tarp. Sides must be somewhat sealed to prevent air flow in or out. A bowl or other water collect piece of equipment is placed in the center of the tarp but below the tarp. A rock is place on the tarp. The rock forces the tarp down. As the sun evaporates the water below the tarp it condenses on the tarp and drips into the collection bowl.
Oh and obviously streams and ponds or lakes are great sources of water but purification of the water is must before drinking any of it.
When the opportunity arises collect rain water in any containers you have. Use leaves or tarp material etc to funnel even more water into your containers. This water should be good to drink without purification.
Boiling water is a surefire way to purify it for consumption. Water needs to reach its boiling point and remain boiling for 1 minute. At higher elevations water will boil at lower lower temperatures and a good rule of thumb is to boil 1 minute plus and additional minute for every 300 feet of elevation.
WATER FILTRATION DEVICES
Filtering water that can't be boiled is better than nothing but never filter if boiling is a viable option. Water can be filtered through sand, charcoal, clothing or bamboo. The longer it takes the water to percolate through the filter material the better it will be filtered. But small organism that cause all sorts of illnesses will not be totally removed. So again... boil if possible.
Here are a number of methods to get pure drinking water!
1. Ways To Boil Water
2. Simple Solar Distiller
3. Solar Distiller