What is the Water Cycle?
Can you guess how old the water in your glass is? It may have fallen as rain last week, but the water itself has been around for as long as the Earth has.
When fish first crawled out of the ocean onto the land, your glass of water was part of that ocean. When the Apatosaurus walked through lakes feeding on plants, your glass of water was part of those lakes and plants. When wrote his plays, your glass of water was part of the water he drank.
The water cycle is the movement of water on, above, and below the Earth's surface. Water is all around us. The amount never changes, but water is always in motion and keeps going around and around.
How Does Water Move in the Environment?
Rain or snow falls to Earth. Water soaks into the soil, flows into the ground below the surface, or travels downhill as runoff and eventually finding its way into large rivers, lakes, and oceans. Watersheds are the area of land where surface runoff drains into the same body of water, like Lake Winnipeg.
Water also evaporates into the atmosphere where it can cool, condense, and fall to the ground as precipitation again. Water changes its state and location in the water cycle, but the amount of water remains constant on Earth.
Fresh Water is Essential
If water disappeared on this plant, life would quickly follow. We can survive about a month without food, but only five to seven days without water. An adult's body weight is about 60% water, which allows us to eliminate wastes, regulate body temperature, and transport nutrients, vitamins, and minerals throughout our body.
Because we are dependent on water for all our needs, it's critical that we maintain fresh, clean water sources. We need water for washing, cleaning, cooking, and growing our food. Much of our fresh water is used outdoors for watering lawns, flower beds, and vegetable gardens, as well as washing cars and filling swimming pools. Humans also use water to generate electricity, manufacture goods, and transport people and products.
Canada's Role in the Water Cycle
The world's freshwater resources are unevenly distributed. A large fraction of global water resources is available in Canada. As a result, Canadians are at the top of water consumption; the average Canadian uses 327 litres per day in their home. How much do you use?
As the human population rises, we put tremendous pressure on our resources. There are approximately one billion people in the world who do not have safe drinking water. Many communities in Manitoba are still without a reliable source of drinking water.
As our communities grow, so have our actions affecting the health of the Lake Winnipeg watershed. The population in the Lake Winnipeg watershed has grown from 2.5 million in 1974 to around 7 million.
Pollutants in the Water Cycle
The specific effects of water quality deterioration caused by human activities depend on what kind of pollution it is and where it occurs. Manufacturing industries, health centres, wastewater treatment facilities, and individual actions can pollute many water bodies near cities and towns. Nutrients entering our water can contribute to excessive algal growth in Lake Winnipeg.
When we drive our cars, the burning of fossil fuels releases pollution. This pollution enters the atmosphere and then falls to the surface with rain, entering our watershed. Also, the generation of electronics, pharmaceuticals, and paint waste can lead to water contamination if not properly recycled.
Pollutants can affect aquatic habitat and disrupt the natural food web. Toxins such as lead, mercury, and cadmium are ingested by small organisms, which are later consumed by small fish and shellfish. Fish, birds, and mammals higher on the food chain are then affected. Eventually, humans are harmed by this process as we are at the top of our food chains. People can get sick by eating seafood that has been poisoned or by consuming contaminated water.
Pollutants aren't always easy to remove from the water, which damages the quality of our drinking water.
Here's What You Can Do
We all impact water through our day-to-day activities and choices. We all have a role to play in ensuring toxins and excess nutrients don't enter our waters. It's a lot easier than some people assume. A good general rule of thumb is always to treat water as if you HAD to drink it. This means:
Not being wasteful with water
Never putting used oil, other chemicals, or harmful substances (like excess fertilizers) down any drains or in drainage ditches
Learning where to recycle things that you shouldn't toss in the garbage or recycling bin (such as electronics, medications, and paint)
Find out more ways you can act now to protect our lakes.
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