The world's water supply is at risk with the rate we are using water. It's one thing to use water from surface sources, but another for sub-surface water to be tapped (so to speak). Water conservation is imperative for our own sake. Water is a more limited resource than most people realize.
Access to clean and healthy water is an important part of our lives and is often taken for granted. Have you ever stopped to wonder about the source of our water supply? Despite the fact that approximately 71% of the Earth is covered with water, the water supply required for human consumption is fresh water, not salt water. Amazingly, only 2.5 percent of all the water on Earth is fresh water, two thirds of which is frozen in icebergs, glaciers and polar ice caps. The remaining one third of fresh water available for human use is found in surface water and sub-surface water. That equates to about .008 percent of the world's water being potable.
Surface Water
Surface water is the water that can actually be seen on the surface of the earth. This includes water in lakes and ponds, rivers and streams, and wetlands. While surface water is replenished by precipitation, the total amount of water storage capacity in a surface water system can be influenced by man. For example, artificial reservoirs can be built to increase or decrease the water supply, and the storage capacity of lakes can be increased by digging lakes deeper and wider. But wetlands are being consumed daily for "progress" and development.Sub-Surface Water
Sub-surface water refers to water that is underground in the water table, soil and aquifers. Sub-surface water flows beneath the earth's surface within aquifers located below the water table. In addition, sub-surface water is located in the small spaces between soil and rocks. One huge difference between surface and sub-surface water is that the storage area of sub-surface water is substantially larger than the storage area of surface water. As such, sub-surface water sources can be tapped for a much longer time before damaging the aquifers. And it takes longer to replenish sub-surface water than it does surface water.
The cycles of both surface and sub-surface water are the same: inputs, outputs and storage.
- Inputs -- Surface water input is from precipitation, whereas sub-surface input is seepage from surface water.
- Outputs -- Surface water output is by evaporation, sub-surface seepage, flow into the ocean, and human usage. Sub-surface outputs are natural springs, wells, human extraction, and seepage into the ocean.
- Storage -- Surface storage occurs naturally in nature (lakes, streams, etc.) and also in man-made sources (reservoirs and detention ponds). Sub-surface storage is an integral part of the Earth's structure in the form of aquifers and the water table.
Threats to Water Supplies
While the availability of surface and sub-surface water seems abundant, the truth is that our water supply is limited and what we have can is being threatened. The threats are coming from:
- Pollution:
Water pollution is clearly a huge threat to our water supply. - Climate:
Increases in the temperatures not only impact our weather with both droughts and floods, but also man's increased demand for water via water sprinklers, farm irrigation and even recreation to cool down on a hot day. - Human Consumption
As the Earth's population increases, the demand for fresh water increases for both human consumption, recreation, industry and agriculture. This extra demand may deplete the Earth's surface water and underground aquifers.
In response to the threat to our water supplies, scientists are searching for ways to increase our water supply. One process is called desalinization, whereby ocean water is converted into fresh water. However, since desalinization is a very expensive process, it is not a viable option to increase the water supply on a large scale.
Another idea to increase our water supply is to get icebergs from their icy homes to a closer destination where the ice can be melted into usable water. Again, this option has not proven to be feasible.
Clearly, human beings need fresh water to live, and protecting our water supply is becoming more and more vital each day. Water conservation is a huge part of the solution. Water isn't as abundant as people, especially in western and developed countries, want to think. It's critical to our very live for us to protect our water supplies at their very source.
