Ever wonder where the water in your tap comes from, or where rain goes once it hits the ground? Every drop of water belongs to a watershed. Across Canada, watersheds quietly support life, shape ecosystems, and sustain our communities. And…did you know? Canada supplies about 20% of the world’s freshwater (35% of which is considered “renewable”), with most of that water held in the Great Lakes–St. Lawrence basin, making the protection of Canada’s watersheds more important than ever in the face of global climate change.

First, what exactly are watersheds?

Watersheds, also known as drainage or catchment basins, are areas of land that drain into marshes, streams, rivers, and lakes, which, in turn, flow to a common outlet such as a larger river, lake, or other body of water. Some watersheds cross municipal, provincial and even international borders. Watershed sizes can vary from millions of acres to just a few acres that drain into a pond, depending on the scale at which the watershed is defined. In Canada, watersheds are categorized as primary, secondary, tertiary or quaternary. 

Why healthy watersheds are important:

Healthy watersheds provide a wide range of benefits that sustain and enhance the quality of life for both people and the environment. They are essential to the health of forests, wetlands, rivers and wildlife, while also providing recreational opportunities and green spaces that support human wellbeing. Healthy watersheds also help communities adapt to the impacts of climate change by reducing flood risks, improving water quality and storing carbon; and contribute to local economies. Because of these many benefits, effective, integrated watershed management to conserve, protect, and restore them is of utmost importance. However, watershed management can be challenging, as it requires well-designed and adaptive plans and strategies that balance environmental protection with economic activity and societal needs.

Key threats to watershed health:

Ironically, many of the key threats to watershed health are the same challenges that healthy watersheds help mitigate, including:

• Pollution, both non-point source (e.g. urban run-off) and point source (e.g. factory discharge)
• Altered or reduced water flows and habitat loss through intentional human development or land-use conversion
• Changes in precipitation patterns and rising temperatures as a result of climate change that lead to increased frequency and intensity of floods and wildfires

Impacts of climate change:

• Reduced water flow
• Warmer surface water
• Loss of wetlands
• Loss of forest cover
• Loss of plant and animal biodiversity
• Loss of pollinators

What is Integrated Watershed Management?

As defined by the Canadian Council of Ministers of the Environment (2016), integrated watershed management (IWM) is “a continuous and adaptive process of managing human activities in an ecosystem, within a defined watershed.” Most provinces and territories in Canada have some form of IWM (or similar) mandate with varying levels of governance and decision-making. For example, in Southern Ontario, Conservation Authorities play a key role in IWM.

Core principles of the IWM approach:

• Is grounded in science
• Focuses on protecting, conserving, restoring and enhancing aquatic and terrestrial ecosystems
• Requires communities and municipalities to work together to identify and prioritize the issues that need to be addressed
• Considers environmental, economic and societal needs, recognizing that they are interconnected and can influence one another in both positive and negative ways
• Employs an adaptive management approach, ensuring plans and strategies are monitored and updated over time
• Relies on collaborative governance across many levels