The first area we'll look at is our hydrologic cycle and the importance of water quality at this beginning level.
The water that remains on land flows and drains into a shared destination of some kind. Whether it be a river, pond, stream, lake or estuary, these are our homes' watersheds. A watershed has three main functions. First it captures precipitation in the form of snow, ice and rain. The characteristic of the watershed depends on how much is captured. For example, a large lake will take in much more water from precipitation than a small stream.
As with almost any area in a developed region, humans have disturbed and changed nature and the natural flow of water to benefit our lifestyle. While it is important to have a high-functioning society with plenty of resources, there is a fine line that is easily crossed when we modify the earth and water cycle.
Another example is when waterways are straightened or moved for the sake of industry and development. When the flow of water is changed it will disrupt the natural sediments on the bottom of the river that water is sifted through. Again, while this may not seem like an issue in water quality, it absolutely can be. The fine and natural sediment and rock that our water flows through is the most natural filter one could find. When those rocks and sediments change through an unnatural process the water flowing to our watershed and into our groundwater actually becomes less clean and less filtered. This means we need to do more of the cleaning and filtering ourselves through the use of energy and unnatural filters and media. These unnatural filters and media can actually remove some of the good components of water, such as minerals, which are important to our bodies.
Even small changes to the grade and surface of landscaping changes how water flows from the precipitation stage into our larger bodies of water and ultimately into our groundwater and watersheds.