Water: A Plain English Guide
We all know that water is essential for our lives. Sometimes we don't always take time to think about how the quality of water affects not only our own health, but that of our environment as well. Water has a powerful impact on the balance of the environment. Too much, too little or ‘not the right sort' can have a devastating effect.
For further information about Water in Australia please see the following publication from Australian Water Association.
The Water Cycle
The amount of water we have on earth does not change. No ‘new' water is created and only a very small amount of water is lost from the upper atmosphere. When water evaporates, it forms into clouds and returns to earth as rain. The amount of water that evaporates each year and the amount that rains back to the ground is virtually constant. If we have a drought, it is not because the world's rainfall for the year is less, but because the rain is falling somewhere else and not on us.
When water evaporates it leaves behind the other molecules it was associated with and is thereby purified.
Natural changes in water quality occur as a result of geological or climatic processes such as erosion, drought, and flood. Human activity can greatly accelerate the changes. The way we manage water and wastewater can make visible impacts of the environment.
When the world's population was smaller and people were hunter gatherers, the natural environment was relatively balanced. Our freshwater supplies and rivers were unstressed. Water was used, became ‘wastewater' and nature recycled it. The diagram below shows the process of the Water Cycle.