World Water Day is celebrated on March 22nd and has been convened by the UN since 1993 to highlight the importance of freshwater on people’s lives and the environment.
Freshwater represents approximately 2.5% of water on our planet, as most of it is saltwater. Of this small percentage, 68.9% is stored as ice, 30.8% exists as groundwater, and just 0.3% is represented by water in lakes and rivers. These numbers are an actual representation of the dynamic water cycle, which tell us how water behaves along space and also time.
Understanding the basics of the water cycle can inform us then about the distribution and pervasiveness of pollutants in the water. The renewal period of lakes is on average close to 17 years, rivers close to 16 days, and of groundwater 1,400 years. This means, in simple terms, why pollutants released into rivers reach out far in distance in short times, and why they can stay in lakes long time. The flow of groundwater is so much relatively slower, so that once an aquifer gets polluted, it means it will take a long time for its water to be renewed (and purified). Canadians across provinces, on average, use 30% of groundwater, and in some provinces like Nova Scotia, is close to 100%.
Because of the increasing environmental impact of industrial activities and urbanization during the last 60-70 years, we have been affecting not only the quality of water along its cycle but also its quantity. Extraction of groundwater for the bottled water international industry has reached excessive levels, which may be affecting local usage of water. Such is the case of Nestle Water wells located in Ontario, where water has been extracted since 1980, with quantities reaching up to 4.7 million litres/year. Another critical example is the groundwater extraction needed for bitumen production in the Alberta Tar Sands (close to 140,000 km2 in area), where it reaches 126 million of gallons of water each day.
The water cycle is being affected day by day, and directly and/or indirectly our livelihoods are related to this. The Water Footprint Network designed an online calculator for people to learn about their water usage, which depends on their resident country, as each place in the world differs in how much local water they use, and how much water they import (https://waterfootprint.org/en/resources/interactive-tools/personal-water-footprint-calculator/personal-calculator-extended/). This calculator takes into account direct and indirect usage, as water use goes beyond what comes from our taps. Indirect water use, or virtual water, involves the water that has been incorporated in food and clothes, and also water used to produce electricity. Unaware of this, we consume every day large quantities of water, more than we can imagine (Canadian average equals 6,400 litre/day).
Students from ENV337 ‘Human Interactions with the Environment’, estimated during the 2019 Winter term, their water footprint based on this calculator by taking daily measurements over a period of a couple of weeks. They presented their reports and shared their estimations as part of their course evaluation.
Inspired on this activity, students made creative videos to share with everyone their learning experiences. World Water Day is being celebrated on March 22nd, and these videos are a contribution to bringing awareness on how much we take for granted the water that we use every day in our lives.
Written by Carlos Avendano, Sessional Lecturer ENV337 (2019)