It owns about 16,000 hectares (40,000 acres) of land in the Toronto region, and it employs more than 400 full-time employees and coordinates more than 3,000 volunteers each year.

TRCA's area of jurisdiction is watershed-based and includes 3,467 square kilometres (1,339 sq mi) – 2,506 on land and 961 water-based in Lake Ontario.

The lands that TRCA administers are used for flood control, recreation, education and watershed preservation activities, including drinking water source protection.

It advises partners about land use, development proposals and construction, and environmental education to help students and community members appreciate their local environment and learn to look after it.

This work is focused in and around Toronto, including portions of the Regions of Peel, York and Durham.

[4] Watershed management also included promoting activities such as recreation and public education on authority lands.

After the deaths and damage of Hurricane Hazel in 1954, governments recognized the need for improved regulation of river floodplains.

[7] The 325-hectare property hosts educational programs for students, workshops for industry and the general public, and technology demonstrations in a park-like setting.