No matter where you live, work or play, you live in a watershed. Wildlife lives there, too. A watershed is an area of land that water flows across or through on its way to a particular water body, such as a stream, river, wetland, lake or coast. Think of it as the land upon which precipitation (such as rain) fails and flows to a common, watery place.
Your Backyard Watershed
Even your backyard is a watershed. Next time it rains, notice how rainwater moves across the land. Some is absorbed by the earth and refreshes thirsty plants and creatures. Some fills up and stays in holes, creating puddles until it evaporates. What's left over keeps flowing until it drains into a common place like a river or lake. If rainwater (or melting snow) in your neighbourhood flows into the same watery spot, you and your neighbours, including wildlife, likely share the same watershed.
Discover Your Watershed Address
You can tell watersheds apart by their boundary. Ridges (or high areas such as hilltops) form a natural boundary of a watershed from which water drains either toward or away from a particular watershed. Some watersheds are tiny, only a few hectares in size. The largest are gigantic, millions of square kilometres large.
Canada has five main watersheds: the Arctic, the Atlantic (which includes the Great Lakes and the St. Lawrence River), Hudson Bay, the Pacific and the Gulf of Mexico. Each of these massive landscapes contains a network of sub-watersheds, most of which are connected through configurations of tributaries (streams and rivers) that channel water to an ocean. Research online to find your watershed "address" within one of these five areas!
Open or Closed Systems
Most watersheds in Canada are called "open systems" because they eventually drain into an ocean. If water within a watershed can only escape through evaporation or by seeping into the earth, it's called a "closed system," such as Redberry Lake in Saskatchewan.
Groundwater is Part of a Watershed
Water beneath the ground is called groundwater. Like the water on the ground's surface, groundwater drains into water bodies such as streams, lakes, rivers and the ocean — but the process can take 10,000 years or more! Groundwater can also discharge as a spring or a flowing well.
Why Watersheds are Important
From towering mountains to flat prairies, from die tundra to ail ocean coasts, from cities to towns, villages, ranches and modest farms, everyone lives in a watershed. Here's a list of some of the many vital needs served by watersheds:
Water: Watersheds supply water — a fundamental need of all living things. Without it, people and wildlife can't survive.
Drinking water: People and wildlife need drinkable water. Watersheds provide the water that enters our homes from wells or from systems of pipes from a treatment plant. We use it for cooking and other household needs. Wildlife also needs sources of safe drinking water.
A place to live: Watersheds are like huge neighbourhoods within which all living things — plants, animals and people — share water.
Wildlife habitat: Whether it's a bird, butterfly, beat or bat, ail wildlife needs habitat. Water is a vital part of their habitat, which also includes food, shelter and space, arranged just right for each species. Beavers, fish, shore birds, frogs, turtles and snakes are among the aquatic species of wildlife that live in or around the water supplied by a watershed.
Irrigation: Farmers draw on water in watersheds from the Earth's surface (such as ponds) or from beneath the ground to irrigate crops for food and provide water for livestock.
Industry: Most industries draw water from watersheds in manufacturing processes or for cooling and cleaning. Fish industries depend on water from streams, lakes, rivers and oceans.
Recreation: Watersheds provide the lakes, streams and rivers we use for fishing, boating, swimming, ice fishing or relaxing on a beach.
Beauty: Scenic waterways or ocean coasts are among the natural features in our landscape that give us cause to reflect, admire and share in the beauty of our environment.
Discover Your Watershed
Each watershed has its own combination of water and land features. Discover them in your area by using the handy list below.
Land formations: Both gradual and catastrophic events such as the ice ages and volcanic eruptions sculpted many landforms, such as the mountains and valleys that we see today. Flowing water also plays a current role in forming, shaping and altering river channels, flood plains and their surrounding landscapes. Investigate your watershed for notable landforms.
Wildlife habitat: Wildlife (non-domesticated plants and animals) needs habitat — food, water, shelter and space arranged just right for each species. Without it, wildlife can't survive. How abundant and diverse are the species of wildlife living in your watershed? Rate the quality of your watershed.
Shoreline and upland vegetation: A shoreline is where water meets the land. Well-vegetated ones serve as buffer zones as do vegetated areas growing in higher places above a water body (upland). Vegetation anchors the soil and protects edges from erosion. Its presence provides wildlife habitat. Its abundance helps to purify water by filtering out impurities as it flows into a water body. Its shade keeps temperatures cool for aquatic life. How lush are the buffer zones in your area?
Lakes: Lakes are big holes filled with standing water that are typically fed by rivers, springs or precipitation. Different types are found across Canada. Discover those in your area by using Canada’s Aquatic Environments website.
Rivers and streams: What do rivers, streams, creeks and brooks have in common Flowing water! Smaller bodies of flowing water are typically called streams; larger ones are known as rivers. They're always heading downward — downstream — the path of least résistance. Find out which communities are upstream and downstream from you by noting the direction of the flow of a nearby river. What are the names of rivers and streams close to your school and home?
River systems: As creeks and streams join other streams, a branching effect starts. This network is a river system. Rivers start at a source (a high point that’s a watery spot such as a spring or a wetland). Gravity propels their flow down channels to their mouth (end point). Ultimately, ail river systems drain into the ocean (except in closed watersheds). Set a course for a "canoe" trip along a river system in your area.
Wetlands: Wetlands are areas that are covered with water for part of a year (or even part of a day as in the case of tidal marshes). Several different types of these immensely productive areas for wildlife occur in Canada. Visit the wetlands section under Things You Can Do on the Hinterland Who's Who website at www.hww.ca for details on how to help these important wet places.
Aquatic ecosystems: An aquatic ecosystem is a group of interacting organisms that depend on each other and their watery environment for nutrients and shelter. Lakes, rivers, streams, wetlands, estuaries and even floodplains arc examples of different types. Each offers different habitat for the wildlife associated with it. For instance, fast-flowing streams appeal to wildlife adapted for moving water, such as salmon, which are not found in the still waters of lakes.
Discover How People Use Land and Water in Your Watershed
Land: How we use land affects the quality of water and aquatic communities. It’s a relationship that’s easy to see when we realize that water drains from the land into water bodies. We practice agriculture, harvest timber, develop areas for urban growth and industry, and build transportation routes, energy infrastructures (dams), resorts and our homes. Where and in what ways is land used in your area?
Water: Impounding water in dams to produce electricity and extracting water for drinking, irrigation or mining are ways we use water. Did you know that waste-water treatment is also an example of water use? Most waste water is the water from your sinks, tubs and toilets at home, and the water discharged by industries in manufacturing processing. Where and how do people use water in your area?
Threats to Watersheds
Land alterations: Anything we do on land within a watershed affects the water within it. Often when we alter land, the earth can no longer absorb water easily. Instead, it flows directly into surface waters like rivers, and may carry many pollutants with it that can harm both wildlife and humans.
Impervious cover: Impervious cover is the sum total of all hard surfaces within a watershed. It includes such things as parking lots, roads, sidewalks, driveways and other surfaces that limit the ability of rainfall to be filtered through soil to groundwater.
Urbanization: Replacing vegetation with impervious surfaces increases runoff and the amount of contaminates flowing directly into streams and lakes. Channelizing small streams and using storm sewers to transport water quickly can increase flow rates and flood areas downstream, affecting aquatic and human communities.
Land-based water pollution: Did you know that most water pollution is caused by people? Litter, pesticides and herbicides, fertilizers and sewage are among the pollutants that find their way into water.
Vegetation removal: Removing vegetation along river banks and shorelines can destroy habitat for wildlife on the land, and increase sediments and nutrients to the detriment of aquatic life.
Altering water flow: Water flow is modified when water is impounded or diverted by dams. Natural flow regimes, temperatures and amounts of dissolved oxygen arc among the elements that change and can harm wildlife.
Agricultural practices: Removing streamside vegetation for pastures, applying fertilizers and pesticides that run off into water, allowing livestock to contaminate water systems and withdrawing water for irrigation in ways that dewater streams can ail harm aquatic communities.
Timber harvesting: Timber harvesting can alter stream flow, habitat for forest wildlife and the age of stands. Some animals that need old-growth conditions in forests, like the spotted owl, can be adversely affected whereas others, like the white-tailed deer, might flourish.
Mining operations: Mining activities basically remove soil and rock from the earth, which are then processed in plants. Tailings (residues from ore concentrations) can contain toxic chemicals and are often stored in piles or ponds close to a mine, making them accessible to water and increasing the potential for heavy metal contamination in aquatic communities.
Invasive species: Alien invasive species introduced from different parts of the planet can overwhelm the land and water. The zebra mussel, spiny water flea and purple loosestrife are among the invaders that compete with native wildlife and speed up the loss of their habitats.
Accelerated climate change: The Earth's climate supports life thanks to the greenhouse effect. Greenhouse gases — carbon dioxide, nitrous oxide and methane — trap solar heat in the atmosphere, maintaining temperatures well above those expected of an Earth without them. With industrialization and rapid growth over the last century, greenhouse gas levels have soared, warming up the planet and resulting in climatic changes. When temperatures rise, air can hold more water and more polar ice melts than refreezes. Warming trends speed up exchanges of water between the land, ocean and atmosphere. These effects can influence the supply of water available in watersheds for plants and waterways, which in turn affects all living things that live in and around them.
Who Protects Watersheds?
Water is a shared responsibility among federal, provincial, territorial and municipal governments. Provinces look after water within their boundaries. Municipalities take care of water treatment and delivery. The federal government has authority in the area of navigation, fisheries, federal land (such as national parks) and the water we share with the United States. Non-governmental organizations and local volunteer groups can give watersheds a boost. You, too, can protect your watershed.
Take Action at School to Conserve Your Watershed
- Start in your schoolyard. Don’t give land-based pollution a chance to start its journey downstream. Reduce the use of pesticides at your school.
- Rejuvenate shorelines along waterways. Keep water systems healthy by planting native trees along stream banks or by organizing a beach sweep to remove litter before it harms wildlife. See the Hinterland Who's Who website at www.hww.ca under Things You Can Do.
- Take a virtual field trip and learn about lakes, rivers and wetlands. Knowledge gives you the power to assess what actions can boost your watersheds health. Visit the Canada's Aquatic Environments website and discover the mysteries of watery places.
- Photograph land and water features in your watershed and submit them to CWF. Help raise awareness about your watershed by snapping photos of its features for an exciting website that will feature all watersheds in Canada.
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