Water is our lifeline that bathes us and feeds us. In ancient cultures water represented the very essence of life. The Romans were the first to pipe water into their growing cities, especially with their aqueducts. They also realized that sewage water could cause damage to their people, and needed to be removed from large areas of people.

Water has played a role not only in the history of countries, but in religion, mythology, and art. Water in many religions cleanses the soul through holy water. For example, the water at Lourdes, France is thought by many religions to be sacred water with healing powers. In Egyptian mythology, the Nu was the beginning of everything and represented water. It brought life to their people, but in drought, produced chaos.

Water has always been perceived as a gift from the gods as it rained from the heavens.

The water or hydrologic cycle explains interactions between the atmosphere, hydrosphere, and lithosphere. The water or hydrologic cycle is a major driving force on our planet. Water is in constant motion, evaporating into the atmosphere from oceans, lakes, rivers and streams. When the atmosphere can no longer support the moisture within the clouds, we experience rain, snow, hail, or sleet. Some water is locked in the form of ice at the polar caps and in glaciers. Water melts in the spring, producing runoff, that percolates through the Earth as groundwater (subsurface) or makes its way back to the sea (surface). The oceans contain most of the water, but it is salt water which is unusable by most organisms. Only pure H2O (water) can interact with organisms.

The movement of the oceans also has a direct effect on the atmosphere. The atmosphere is that envelope of gas that keeps organisms living on this planet. Oceans and atmosphere interact to give us weather.

Water provides the Earth with the capacity of supporting life. An organism doesn’t have to be told how important water is to their existence. An amphibian knows to lay their eggs in water or else there will be no new born. Even flies know to lay their eggs in fresh water.

The only organism that doesn’t understand the importance of water is humans, especially in industrialized countries. Children in those societies turn on the water in a sink and never think about the trouble someone has gone for that "miracle" to occur.

In the United States it is mandated by law that its citizens should be given clean and abundant water. Dams, reservoirs, filtering plants, and pipes all bring clean water when the facet is turned on. Sewage water is only mixed with recycled water supplies after the water goes through rigorous cleaning methods. Water borne diseases do not effect the U.S. population like in other countries that do not treat their water supply.

Schistosomiasis worms, parasite in water.

Water borne diseases are any illnesses caused by drinking contaminated water. Diseases can include infection from bacteria (Salmonella), viruses, or by small parasites (Cryptosporida, Giardia, and Toxoplasma). These organisms and viruses cause diseases like cholera, typhoid fever, malaria, botulism, polio, dysentery, giardia, and hepatitis A. One of the first symptoms of these diseases is diarrhea, which cause about three million deaths throughout the world, mainly in India, Africa, and South America.

Sewage is sometimes discharged into rivers, where children downstream might be taking a bath or using the water to drink. The simplest treatment method is boiling. Just bring the water to a boil for at least one minute, then allow it to cool. But this is not always effective in heavily chemical polluted water supplies.
Without water, organisms could not exist. Water is a resource that should not be taken for granted. It needs to be conserved, just as we save other valuable resources.

Water is one of the weirdest compounds known to humans. The difference between the boiling point and freezing point of water is one of the largest ranges of any compound. It is this span of temperature that mirrors the range of where life can exist, from bacteria to humans. Water also has a very high specific heat, which means that it can absorb or lose much heat before its temperature changes. This is important in maintaining body heat in mammals. It also takes a lot of energy before vaporization can occur. For this reason, water evaporates slowly from ponds and lakes, where many life forms are dependent on a stable, warm environment.

Water is less dense in its solid state than in its liquid state, so that ice floats instead of sinking. This property permits life to develop in polar and subpolar regions where ice floats and allows life to continue living below the surface. If ice were heavier than water, it would sink, and more ice would form on top of it. As a result, all life in the waters would be trapped in the ice in the many areas of the world where it gets cold enough to freeze water.

Water is a remarkable solvent, where most elements and compounds can dissolve in its powerful molecular structure. Gases such as oxygen and carbon dioxide, can also dissolve, making it readily available for photosynthetic and nonphotosynthetic organisms to use.

Resistance of water to a disturbance.

Water also exhibits viscosity. One can observe the effects of viscosity alongside a stream or river with uniform banks. The water along the banks is nearly still, while the current in the center may be swift. This resistance between the layers is called viscosity. This property allows smaller fish to live near the shore, while larger fish are able to swim efficiently in strong currents. Viscosity is also responsible for the formation of eddies, creating turbulence that leads to good mixing of air in the water and more uniform distribution of microscopic organisms.

How water provides all these properties are complex, but only emphasizes the importance of water to every organism on Earth.