Water is vital for all known forms of life. As such it is the greatest human need, after oxygen. Humans need clean water for drinking because if you don't drink water or take it in through the food you eat you die. It is also important for the water to be clean because drinking water with harmful substances can cause major illness and death in humans.
On Earth, 96.5% of the planet's water is found in seas and oceans. Only 2.5% of the Earth's water is freshwater, and 98.8% of that water is in ice and groundwater. Less than 0.3% of all freshwater is in rivers, lakes, and the atmosphere, and an even smaller amount of the Earth's freshwater (0.003%) is contained within biological bodies and manufactured products.
Water's most obvious use is for drinking but it has several other important uses. Water is used for bathing, washing dishes, cleaning clothes, irrigation for food growing systems, and recreation & entertainment.
In modern society most homes are delivered water through municipal water supplies or by drawing water from a well. Preparation and storage of this water is important because government water purification is often done with harmful chemicals, groundwater from wells could be contaminated or have undesirable qualities such as being hard or soft, and the supply from both of these sources often depends on other systems of support such as the electrical power to run pumps.
- From government (city, county, municipality)
- Rain Collection
- Water Well
- Drawing from streams, lakes, ponds, or rivers
"Tap water" is potable water that has been filtered and treated according to government standards. However, during a disaster tap water may not be available or may be contaminated (i.e. by sewage or chemicals) due to pipes breaking and/or flooding. Clear water taken from natural sources other than rain or a well should be considered non-potable and treated before consumption. Even water from these latter sources may become contaminated and require filtration or other treatment. When in doubt about a water source, filter then treat or boil the water.
- Filtration Equipment is often the fastest and safest way of purifying water from a questionable source. It physically remove nearly all biological and chemical contaminants within the limits of the filter. Its' disadvantage is that it is a slow process and works only if there is a water source available during a disaster. For storing water prior to an emergency a filter is generally not required.
- Chemicals, such as tincture of iodine and household "chlorine bleach", a solution of approximately 3–6% sodium hypochlorite (NaClO), are a quick and easy way to kill most bacteria and viruses. However they will not remove other chemicals and can be adversely effected by water conditions such as temperature and debris.
- Boiling will kill virtually all bacteria and viruses regardless of other water conditions and requires no consumables or equipment beyond a container to boil in such as a pot. However, it can be somewhat time consuming and will not remove most chemical contaminants.
Once water is prepared, it must be stored so that it is readily available when needed. Water may be stored in any clean bottle, bladder, or other food grade container. Clean, 2 litre soda bottles are a good way to store larger quantities of water as these types of bottles are designed to be non-reactive to their acidic contents, and to also resist the pressures generated by the carbonated water. The important thing to remember when storing water is to rotate your water regularly. Water can become contaminated over time with either chemicals leaching from its container or slowly growing bacteria given enough time and light, so it should never be left stored for too long.