Since that second grade science lesson with Mrs. So-and-so, you’ve been familiar with the water cycle (also known as the hydrologic cycle). Evaporation, condensation, precipitation, collection, and repeat. The process begins when the sun heats up bodies of water and vaporizes into the air. The vapor eventually gets cold at higher elevations, and changes back into a liquid state, forming clouds. Precipitation, which falls in many forms, occurs when condensation has amassed greatly in a cloud, and the air can no longer hold it. Once the precipitation reaches the earth, the water collects in rivers, lakes, oceans or soaks into the earth as groundwater.

Source: Water Cycle Diagram

As the image shows, this natural process reproduces and cleanses water in a continuous cycle. The amount of water within this natural cycle remains constant, meaning the Earth will never have more water than already exists. Even though the earth is covered by 70 to 75 percent water, less than one percent of it is suitable for human uses such as drinking and cooking. The good news is that even though the percentage of water suitable for human uses seems small it is not a finite resource. This is because it is constantly being re-circulated as water from precipitation. While this occurs at a greater rate than humans consume it, the water distribution doesn’t occur proportionately to where populations are concentrated.

The challenge posed by disproportionate water distribution is further exacerbated by the increasing world population and the prevalence of water-contaminating pollutants. Currently, the world population is seven billion, which the UN estimates will increase to more than ten billion by 2100. Ever-growing population and industry contribute to increased surface water and groundwater contamination due to chemical discharge, pesticides and fertilizers from farming areas, wastewater and everyday garbage. These activities can impair and even cause water supplies to become unusable for drinking. Water distribution, population growth and water contamination are all factors that contribute to an increasing number of water scarcity events especially in arid and semi-arid regions.

While solutions such as ocean desalination and long-distance pipelines and aqueducts have been built to ensure adequate water supplies they come at a high price. Water conservation is one of the most effective, local and low-cost solutions. In the United States, the average person uses 80 to 100 gallons per day and typical usage includes:

• • 25 to 50 gallons to take a shower
• • 2 to 7 gallons to flush a toilet
• • 2 gallons to brush teeth

A few simple ways to reduce water use are:

• • Collecting water from your roof to water your garden
• • Soak dirty pots and pans instead of running the water constantly until the dish is clean
• • Always adjust the washer’s water level for the size of the load

What creative things do you do at home to cut back on water usage?