Don River

The Greenbelt protection has extended to 21 major urban river valleys and 7 coastal wetlands across the Greater Golden Horseshoe - including the Don River!

The addition of these waterways to the Greenbelt is an important recognition of the vital role the Greenbelt plays in protecting the hydrological features we rely on for clean drinking water, flood protection, and healthy ecosystems.

Don River is 92 km long and flows from Vaughan, Richmond Hill, and Markham into Lake Ontario. Every 5 years Toronto and Region Conservation Authority releases a report card to assess the health of the Don River Watershed. Grades around urbanized areas typically decline because of reduced natural vegetation and hard surfaces, such as roads and roofs. Protecting the urban river valleys is very important for our communities health. 

Top facts about the Don River:


Decades of urbanization and population growth has placed the river's natural features and functions under stress. The Don River watershed is one of the most urbanized watersheds in Canada.


Minor to major flooding occurs frequently in the Don River. Take a walk on the East Don trail to see an art installation that depicts the different flood levels that the Don River has experienced over the years. 


The mouth of the Don River was built to avoid oil refineries in the early 1900s. The original mouth of the river was supposed to connect with the Lake Ontario more directly, but was diverted to avoid a British American Oil refinery.


Surface water and groundwater quality ranges from poor to very poor. Due to the highly urbanized areas that surround the Don River, large quantities of stormwater runoff ends up in the river decreasing the water's quality.


Forest cover ranges from poor to very poor in the Don River watershed. Ensuring consistent forest cover is very important since forests clean our air, store carbon and moderate temperatures. 

Want to learn more?

Right now, we are working with community groups, municipalities and organizations across the Greenbelt to ensure the urban river valleys and the Greenbelt remain healthy for generations to come.

The Toronto and Region Conservation Authority has produced extensive research about the Don River Watershed.

The Toronto and Region Conservation Authority organizes many events to help you learn more about the watershed, or you could check-out our events page.