About TRCA


Since 1957, Toronto and Region Conservation Authority (TRCA), as enabled through the provincial Conservation Authorities Act, has taken action to enhance our region’s natural environment and protect our land, water and communities from the impacts of flooding and increasingly extreme weather events — Ontario’s leading cause of public emergencies.

As the region’s first line of defence against natural hazards, TRCA maintains vital infrastructure and provides programs and services that promote public health and safety, protecting people and property.

TRCA mobilizes a science-based approach to provide sound policy advice, leveraging its position as a not-for-profit operating in the broader public sector to achieve collective impacts within our communities and across all levels of government.

TRCA’s jurisdiction includes nine watersheds and their Lake Ontario shorelines:

  • Carruthers Creek
  • Don River
  • Duffins Creek
  • Etobicoke Creek
  • Highland Creek
  • Humber River
  • Mimico Creek
  • Petticoat Creek
  • Rouge River

The jurisdiction spans the following six upper-tier and 15 lower-tier municipalities, representing almost five million people (approximately 10% of Canada’s population):

Upper-Tier Municipality Lower-Tier Municipality % of Population Within TRCA Jurisdiction
Dufferin County Mono (Town) 5
Durham Region Ajax (Town) 86
Durham Region Pickering (City) 95
Durham Region Uxbridge (Township) 19
Peel Region Brampton (City) 63
Peel Region Caledon (Town) 55
Peel Region Mississauga (City) 33
Simcoe County Adjala-Tosorontio (Township) 4
Toronto Toronto (City) 100
York Region Aurora (Town) 4
York Region King (Township) 45
York Region Markham (City) 100
York Region Richmond Hill (City) 99
York Region Vaughan (City) 100
York Region Stouffville (Town) 43



The achievement of safe and resilient communities.


The provincial leader in conserving, restoring and managing natural resources to advance safe and sustainable development.


Working with government and the communities we serve to achieve collective impact and advance shared goals.

Core Behaviours

We are honest, ethical, and professional.

We achieve shared goals through a solution-oriented approach.

We are responsible for our actions, behaviours and results.

We recognize and value that our differences make us stronger and we commit to creating a diverse, equitable, and inclusive workplace that celebrates individual contributions to provide dignity for all.

We maintain a high standard of performance and customer service, consistently striving to improve and produce quality work.



map of the nine watersheds in TRCA jurisdiction
Map of the nine watersheds in TRCA’s jurisdiction.