What Is a Watershed?

A watershed is an area drained by a river (or creek) and its tributaries.

In the Toronto region, all watersheds are river watersheds, with the exception of the waterfront, which drains into Lake Ontario.

Toronto and Region Conservation Authority (TRCA) manages nine watersheds, working to minimize flooding and erosion and help the Greater Toronto Area adapt to a changing climate.

These benefits play an important role in keeping our environment healthy and our communities safe into the future.

You’re in a Watershed Now

Wherever you are in the Toronto region, you’re in a watershed. Use the map below to explore the Toronto region’s watersheds.

TRCA’s Role in Watershed Management

Conservation Authorities (CAs) are established and governed under the Conservation Authorities Act.

The purpose of the Act is to provide for the organization and delivery of programs and services that further the conservation, restoration, development, and management of natural resources in watersheds.

Conservation authorities are not the decision-makers in land use and infrastructure planning. Municipalities implement the watershed planning requirements of provincial legislation, plans, and policies.

However, CAs play an important role by advising municipalities and infrastructure providers on matters related to natural hazards, wetlands, and drinking water source protection, and by collecting and providing scientific data on watershed management and resilience to climate change adaptation outside the plan review function.

Conservation authorities also administer a development activity permit process under section 28 of the Act for conservation authority regulated areas consisting of river and stream valleys, wetlands, watercourses, and shorelines.

Watershed Plans

TRCA also fulfills its mandate through the development and implementation of watershed plans.

Watershed planning provides a comprehensive framework, or road map, for ensuring healthy watersheds and building resilience to land use and climate changes.

Watershed planning is vital to understanding the current and potential future conditions of a watershed, and identifying measures to protect, enhance, and restore its health.

Watershed plans provide a comprehensive and integrated understanding of the form and function of the natural hazards, features, and areas that comprise the water resource and natural heritage systems.

Although watershed plans do not determine land use planning decisions, they do help to inform land use and infrastructure planning and other municipal initiatives, such as:

• Climate Adaptation Planning
• Ecosystem Restoration Planning
• Erosion Risk Management
• Flood Risk Management
• Green Infrastructure Implementation
• Land Use and Infrastructure Planning
• Low Impact Development (LID) Implementation
• Stormwater Management Planning and Retrofit
• Urban Forestry Revitalization

Updated Watershed Plans

Carruthers
Creek Watershed Plan

Etobicoke
Creek Watershed Plan

Humber
River Watershed Plan

Take a Deeper Dive:
Learn More About Watershed Management

• Watershed Strategy: Discover the overarching strategy for the sustainable management and conservation of the Toronto region’s watersheds.
• Watershed Planning: Learn about the watershed planning process, including links to current watershed plans which aim to improve the health and resiliency of our watersheds. COMING SOON.
• Watershed and Ecosystems Reporting: Learn what the science and data tell us about current conditions and trends in ecosystem health across the Toronto region.
• Ecosystem Monitoring and Research: Discover the different ways we monitor our forests, wetlands, and waterways, contributing valuable data to watershed management activities.

Contact

TRCA Watershed Planning and Ecosystem Science: wpes@trca.ca