How do we use water?
All living things need water to survive. Humans need between two and five litres of water every day to replace the water that we breathe, sweat or urinate. Although we can survive for about a month without food, we can only survive for five or six days without water. Our bodies are made of about 60 per cent water. We get a lot of water from the food we eat, but most of it comes from the liquids we drink.
Not only do we drink water, we use it for agriculture, transportation, energy production, sanitation, manufacturing and recreation. Because of its importance in so much of our life, understanding its cycle and how we impact the cycle brings us closer to appreciating water and conserving it for the benefit of future generations.
We use more water than we need. Water use statistics from Metro Vancouver show that the average resident uses about 325 litres of water each day—and much of it is wasted! All of this water comes from three separate reservoirs in the mountains. When we waste this water it is not only a waste of precious water, but also of energy and other resources because all our drinking water goes through lengthy treatment before and after we use it. As our city populations continue to increase and our reservoirs remain the same size, water conservation has become more of an important topic.
Where does our water come from?
In British Columbia, we’re fortunate to have access to plenty of clean water, but the water supply isn’t limitless. Our sources of water are replenished by two methods: precipitation, and melting snow. Both of these vary seasonally, and year to year. We cannot use water at a faster rate than the water returns, or else we will be depleting our source of water.
Many places in the world are not as close to the source of their water, and although their water is replenished by the same two methods, their water may have travelled hundreds or thousands of miles before it reaches their homes. For example, much of the interior provinces of Canada use wells, rivers or lakes as their source of drinking water. This water has travelled from mountains, into creeks, down waterfalls, through rivers, and may even be used by other cities along the way, until it finally reaches them. This factor of distance creates a stronger need for more advanced filtering systems because the water will likely have picked up a lot of debris along its way.
What about the water cycle?
The water cycle, comprising of water that evaporates from rivers, lakes and oceans into clouds and falls again as rain, provides Vancouver with an average of 1.58 meters of rain a year. This amount of rainfall defines Vancouver as a rainforest climate. This is an abundant amount of rainfall compared to dry African countries, or even compared to other parts of the province, like the interior. While we get a lot of rain in Vancouver, it falls mostly in the winter. Throughout the winter, we collect this water in giant reservoirs and we rely on this collected amount to last through the hot, dry summers. Therefore, as our urban population increases, our demands on our reservoirs will also increase.
Ideas for conserving water:
- Turn the tap on only to rinse your hands—don’t let the water run.
- Run through the sprinkler only on your house’s watering day.
- Sweep instead of washing the sidewalk.
- Have a short shower instead of a bath.
- Put a milk jug/weight in the toilet tank to displace the water.
- Turn off the tap when you brush your teeth instead of letting the water run.
- Keep a water jug in the fridge instead of running the tap water till it is cold.
- Use a bucket of water instead of the hose when washing your car.
- Wash dishes in the sink, but only let the water run for rinsing.
- Set the washing machine to the short cycle.
- Change the washer on a drippy tap.
- Collect rainwater for watering your garden.
- Drink tap water, not bottled water.
- Research grey water systems and build your own.
- Use your bath water to flush your toilet.
- When it comes to your toilet water, if it’s yellow let it mellow, if it’s brown flush it down.
Condensation: Water collecting in clouds, changing states from water vapour to liquid water.
Conservation: The protection, preservation, management, or restoration of wildlife and natural resources such as forests, soil, and water.
Evaporation: Water leaving the Earth’s surface changing from liquid water to water vapour. Affected by the energy from the sun.
Filtration: Passing a fluid through a filter to separate particles from fluid.
Gauge: A way of measuring how much of something there is.
Grey water: Gently used water that has the potential to be reused.
Reservoir: A natural or human-made lake storing water.
Runoff: Water moving on the surface of the land towards the ocean. It can be in the form of rivers, streams or an overflow.
Water cycle: The continuous movement of water on, above and below the earth.
Watershed: An area where all water drains to the same river or body of water.
Science World at TELUS World of Science | Our World: BMO Sustainability Gallery
Science World British Columbia | BC Green Games
Science World Resources | Full lesson & Other activities | Wonderful Water
Science World Resources | Full lesson & Other activities | Wet and Dry
(a water unit with a kindergarten focus)
Engaging Science | Online Games | Just Drifting Around
Metro Vancouver | K-12 Field trips | Watershed Education
My Water | Kids Water Fun
Project Wet | Worldwide Water Education
Raincoast Education | Grey water Reuse
The Jane Goodall Institute of Canada | Protecting our Sacred Water