Water Use: IrrigationCanadians are among the highest water users in the world, using twice as much per capita as the average European. Despite emerging threats to water security such as climate change, pollution and increasing urbanization, most Canadians do not consider water quantity an issue. Because of our relative abundance of water, conservation is seen as a well-intentioned activity, but not a necessity.

River Flow. Source: Thundershead
Rivers always flow downhill. A stream, or a river, is formed whenever water moves downhill from one place to another. This means that most rivers begin high up in the mountains, where snow from the winter, or ancient glaciers, is melting. On their way down to the sea, they collect water from rain, and from other streams. Rivers also rise up from springs. Where groundwater seeps up onto the surface, it may form a lake or pool or it may start running downhill right away. This is the source of the river. In lower places where there are no mountain peaks covered with snow, rivers often begin this way.

The amount of flow in rivers affects many issues of water quality and quantity together - for example, pollutant concentration, water temperature, aquatic habitat, and recreational uses.

Read more: Precipitation

Read Local: Water Flow in My Watershed

Adapted from Stream Biology and Ecology website in association with Washington University.

Water falls as rain When cloud particles become too heavy to remain suspended in the air, they fall to the earth as precipitation. Precipitation occurs in a variety of forms; hail, rain, freezing rain, sleet or snow.

Different Forms of Precipitation

Rain develops when growing cloud droplets become too heavy to remain in the cloud and as a result, fall toward the surface as rain. Rain can also begin as ice crystals that collect each other to form large snowflakes. As the falling snow passes through the freezing temperatures into warmer air, the flakes melt and collapse into rain drops.

Hail is a large frozen raindrop produced by intense thunderstorms, where snow and rain can coexist. As the snowflakes fall, liquid water freezes onto them forming ice pellets that will continue to grow as more and more droplets are accumulated. Upon reaching the bottom of the cloud, some of the ice pellets are carried by an updraft back up to the top of the storm.

Aerial View of Floodplain

Most flooding occurs when the volume of water in a river or stream exceeds the capacity of the channel. Flooding also takes place along lake and coastal shorelines, when higher than normal water levels engulf low-lying areas.

Natural flooding of rivers revitalises the habitats of many plants and animals and enriches soils for planting. But floods can cause destruction and harm to those who live in their paths.

Flooding is a common phenomenon in Canada, resulting from an increase in stream-flow beyond the point where the normal stream channel can contain the water. When water overspills riverbanks, it spreads out along the adjoining floodplain. Flood-waters may occupy the floodplain for a matter of hours, as in the case of flash floods, or for up to two months, as sometimes occurs during the spring snowmelt runoff period.

Learn about flooding in your watershed

Adapted from Environment Canada's Freshwater website and the National Geographic's Flood and Dams.

Stormwater Drain

When precipitation occurs, several things can happen to the water. Through the hydrologic cycle, natural landscapes, such as forests and wetlands, trap rainwater and snowmelt, and filter it as it percolates into the ground. In contrast, an urban environment consisting of paved surfaces such as roads, buildings, bridges and parking lots, and other impermeable areas such as airports and building sites, interrupt the natural hydrologic cycle by preventing percolation and thereby decreasing the water available to recharge groundwater. Instead of seeping slowly into the ground, water remains on the surface, accumulates and runs off in large amounts, creating the potential for flooding and erosion. This runoff is referred to as stormwater.

Adapted from Pollution Probe's Source Water Protection Primer

Water shortages can lead to drought

A water shortage is when the human demand for water exceeds available water supply. In comparison, a drought is a prolonged period of extremely low or complete lack of precipitation. Droughts are natural events of varying duration that have occurred throughout history and they are part of the natural fluctuations of the planet's climate system.

While droughts can occur anywhere, regions with a semi-arid or arid climate and low levels of annual precipitation are more vulnerable to droughts. In Canada, southern Saskatchewan, Alberta and the interior valleys of British Columbia experience frequent droughts.

Healthy Shorelines

The shoreline is where water meets land. It is a narrow, fragile habitat that is home for many forms of wildlife. Healthy shorelines usually have a strip of moisture loving trees, shrubs, and herbaceous plants - this is called the buffer zone.  The buffer zone:

• enhances the beauty of the shoreline;
• shades and prevents the heating of water, which can kill aquatic creatures;
• protects water quality by filtering the run-off of pollutants like fertilizers and pesticides from land;
• controls soil erosion, which muddies streams and ruins fish spawning habitat; and
• provides food, cover, and nesting sites for a rich variety of life forms on land and in water.

Rain BarrelWater conservation means doing the same with less, by using water more efficiently or reducing use where appropriate, in order to protect the resources now, and for the future.  Using water wisely reduces pollution and health risks, lowers water costs and extends the useful life of existing supply and waste treatment facilities. It is one of the easiest and most inexpensive ways to ensure sustainable supplies of fresh water.