Canada's Freshwater

by Suman Gupta

Canada\'s Freshwater

Canada has an abundance of freshwater, but the majority is nonrenewable. Discover what you can do to help preserve this precious resource.

Water is often thought of as a renewable resource; after all, it’s called a water cycle for a reason, right? Only partially true, this misunderstanding has led to a false sense of water security, particularly for Canadians. The rate at which we use and abuse our freshwater could have damaging consequences.

Freshwater is essential

We rely on freshwater for everything. There is no way around it. We drink it, we use to it grow and produce food, and we depend on it for health care and sanitation.

Diarrhea is the leading cause of illness and death globally, and 88 percent of these deaths are caused by lack of access to safe drinking water and sanitation facilities. In Canada, although the majority of us have access to clean water, health problems caused by water pollution still cost Canadians $300 million annually.

Freshwater is not entirely renewable

Freshwater is characterized by having very low salt concentration and ultimately comes from precipitation. Freshwater makes up only a small percentage of all the water on Earth, and nearly three-quarters of this is frozen as ice sheets, ice caps, glaciers, and icebergs. The majority of the remaining unfrozen freshwater is found underground; what is left is surface water—found in lakes, rivers, streams, and wetlands.

Despite the water cycle, not all freshwater is renewable. If a water source is used up faster than it can be recharged through precipitation, this is considered a nonrenewable water resource.

Groundwater, for example, is recharged at an exceedingly slow rate, and in many parts of the world, overdraft of water from underground aquifers has caused the water table to drop by several hundred feet. Depletion of water from these sources can cause, among other things, collapse of land as the ground above the exhausted water table weakens.

Furthermore, some freshwater in aquifers has been trapped there for thousands of years (fossil water), and is essentially not part of the water cycle. Harvest of this fossil water puts it into the water cycle and may be contributing to sea level rise as more water becomes available to fall during precipitation. Freshwater found in lakes is also not entirely renewable, as lakes are slow to recharge.

Freshwater is abundant—sort of

Canada has an abundance of freshwater, but the majority is nonrenewable, as it is locked up underground in aquifers, frozen in glaciers, or found in lakes. Still, Canada holds a significant proportion of the world’s renewable freshwater supply. Most of this is found in Canada’s vast river systems.

Although not entirely renewable, the Great Lakes are the largest fresh surface water system on the planet. These lakes provide drinking water to 8.5 million Canadians and support a quarter of Canada’s agricultural capacity.

Canada also harbours a high proportion of all the wetlands in the world. Wetlands are vital for capturing, filtering, and recharging freshwater sources. Alarmingly, wetlands are being destroyed more quickly than any other ecosystem in the world. Canada is no exception, and significant wetland losses have occurred due to land conversion for agriculture and urban development.

Freshwater is threatened

Industrial discharges and runoff

Human activity can degrade freshwater quality. Industrial discharge of waste water and runoff from agricultural land, gardens, lawns, roads, and urban areas can pollute nearby lakes, rivers, and streams with various materials toxic to wildlife, habitats, and ecosystems.

Air pollutants

Rainwater contaminated by air pollutants can also degrade freshwater quality and cause acidification or heavy metal accumulation in freshwater ecosystems. Agricultural runoff and detergents containing high nutrient substances, such as phosphorus, can cause algal blooms in water that are also toxic to wildlife.


Ever increasing demands are being placed on our freshwater sources, resulting in significant withdrawals of freshwater from various sources. These pressures include, but are not limited to, the increasing water needs of growing cities, industry, agriculture, and electricity generation. These pressures can cause drainage of freshwater systems or damming and diversion of river flow, which can disrupt freshwater ecosystem processes. When aquatic ecosystem processes are degraded, it can impair the ability of these systems to filter and provide clean water to us.

Climate change

All of these threats are being compounded even further by climate change, which is changing where and how often rain falls, all over the planet. Climate change is also increasing stream temperature in some regions and may be contributing to the significant decreases in maximum annual spring river flow all over Canada, both of which have significant consequences for freshwater habitats and species.

Species losses

Ecologically, freshwater habitats and species are among the most endangered in the world. In North America, the average projected extinction rate for freshwater animals is several times higher than that for terrestrial animals and marine coastal mammals, and is on par with average projected extinction rates for species in tropical rainforest communities. Loss of freshwater biodiversity can upset the balance of freshwater ecosystems, which ultimately alters freshwater ecosystem processes.

What can we do to protect our freshwater?

There are many choices we can make to reduce our impact on lakes, rivers, wetlands, streams, and the species that live there.

Buy organic

Choose unsprayed, pesticide-free produce, when possible. Organically farmed produce is generally a safe bet, but some pesticides used on organic farms, such as rotenone and pyrethrin, can be highly toxic to freshwater ecosystems.

Choose cosmetics without plastic beads

Avoid using face and body care products that contain abrasive plastic beads. Also known as microplastic, these beads have been found in alarmingly high numbers in Lake Superior, Lake Huron, and Lake Erie. Instead choose products that contain natural abrasives, such as sugar, oatmeal, and crushed seeds or nut shells.

Discard potential pollutants appropriately

Do not flush unused medication, cleaners, paints, solvents, petroleum products, or other household chemicals down your drains. These materials ultimately end up in our lakes, rivers, and groundwater supplies, and it takes a surprisingly small quantity of pollutant to contaminate huge quantities of water; for example, one drop of oil can make 25 litres of water unfit for drinking.

Take aggressive action to reduce your contribution to climate change

If you have property on a lakeshore, try to preserve the natural vegetation along the shoreline or restore it to a more natural state if it has already been altered. This will maintain lake water quality, as the plants will be able to filter out contaminants and high-nutrient substances that may otherwise run off the land into the lake.

We rely on freshwater ecosystems to keep us alive. Let’s do our part to help keep these ecosystems, and the species that live in them, healthy! a

By the numbers

  • 2.5%—of the earth’s total water is freshwater
  • 70%—of freshwater is frozen as ice sheets, ice caps, glaciers, and icebergs
  • 30%—of unfrozen freshwater is found underground
  • 0.3%—of unfrozen freshwater is surface water
  • 1%—of Great Lakes water is renewed annually via precipitation, runoff, and infiltration
  • 65%—of Canada’s freshwater is nonrenewable
  • 7%—of the world’s renewable freshwater supply is in Canada
  • 18%—of the world’s fresh surface water is contained in the Great Lakes
  • 25%—of the world’s wetlands cover 14% of Canada’s land area


A surprisingly large amount of water gets used to produce many of the things we eat and use each day. This contributes to our water footprint. The average Canadian has a water footprint of 6,400 litres per day! Want to reduce yours? Here are some ideas to help you get started.

Eat less meat

Meat production uses up significantly more water than production of fruits and vegetables; for example, the average water footprint of beef is 7,030 litres per pound. One pound of beans, on the other hand, has a water footprint of 163 litres.

Cut back on sugar

The water footprint of sugar cane is approximately 682 litres per pound.

Choose to buy local

When possible, buy local in order to reduce the distance your purchase has to travel to get to you. One litre of crude oil costs about 12 litres of water.

Buy second-hand clothes

As well, instead of discarding your lightly worn clothing, give it away to a friend, donate it to charity, sell it via a consignment store, or upcycle it into a new piece of clothing. One pair of brand new jeans costs nearly 11,000 litres of water to produce. A pound of cotton and a pound of wool each cost over 380 litres of water.

Flush less

Toilet flushing may be the single biggest use of water in the household. Depending on the age of your toilet, each flush can use up anywhere from 15 to 19—up to 30 litres—of water. Consider installing a high-efficiency, or ultra low-flush toilet, which uses 5 to 6 litres per flush.

Harvest rainwater

Consider harvesting rainwater to water your garden; 40 percent of residential water treated for drinking is used to water gardens and lawns!

Choose tap water over bottled

Bottled water has a much higher water and environmental footprint than tap water.

For more information about your water footprint, check out

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