Black Creek Drainage Improvement Study

The City of Toronto has completed a Municipal Environmental Assessment (EA) Study to achieve the following for the Black Creek Sanitary drainage area:

  • accommodate flows for projecting 2041 population and employment growth and beyond
  • reduce surcharge levels of the Black Creek Sanitary Trunk Sewer (STS) during wet weather events
  • reduce combined sewer overflows (CSO) discharge to the Black Creek watercourse
  • reduce stormwater infiltration and inflow into trunk sewers

The following are key study recommendations:

  • implement Wet Weather Flow reduction measures along the existing Black Creek STS
  • install two new sanitary trunk sewers and a new combined storage tank and tunnel in the vicinity of Rockcliffe Court
  • complete sewer upgrades along Keele Street between Eglinton Avenue West and Donald Avenue

This study is expected to complete in 2020, with design and construction scheduled after 2025.

Black Creek Sanitary Trunk Sewer Study Area Map

Black Creek Sanitary Trunk Sewer Study Area Map from Steeles Avenue West to St. Clair Avenue West and Scarlett Road to Dufferin Street.

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Built around 1960, the Black Creek Sanitary Trunk System (STS) is a 15 km long sanitary trunk sewer that services the 5,500-hectare drainage area.  The trunk system ultimately flows to the Humber Wastewater Treatment Plant.

During major storms, flows in the trunk system exceed the design capacity. This has caused overloading and surcharging. Also, during some storms, overflows area released from the combined trunk sewers to the Black Creek watercourse, which need to be controlled according to the Ministry of Environment, Conservation and Parks’ criteria.

Over the next few decades, a population and employment increase is expected within the study area, which will need to be accommodated by the trunk system.

Study overview

In 2015, the City of Toronto has initiated a Municipal Class Environmental Assessment (EA) study to address problems and opportunities with the Black Creek Sanitary Trunk Sewer (STS) within study area.

The purpose of the Class EA study is to assess capacity issues of the Black Creek STS and to develop a plan to:

  • ensure the trunk sewer system has capacity to service future population and employment growth
  • better manage flows in the trunk system during rainfall events
  • reduce combined sewer overflows to Black Creek watercourse
  • reduce stormwater entering the trunk system

The Process

The study is being planned as a Schedule “C” project under the Municipal Class Environmental Assessment document.

Ontario’s Environmental Assessment (EA) program promotes good environmental planning by determining and managing the potential effects of a project prior to implementation.

The EA program ensures that public concerns are heard. EA balances economic, social, cultural and natural environmental needs so that projects benefit Ontario.

This study is being carried out according to the Municipal Class Environmental Assessment process. This is an approved approach to satisfying requirements of the Environmental Assessment Act specifically tailored to municipal infrastructure. The process includes identifying the problem or opportunity to be addressed, developing and evaluating a range of alternative solutions, providing opportunities for public input and identifying a preferred solution

Three rounds of Public Consultation Drop-In Events will occur for this Class EA Study project.

  • The first event took place in April 2016.
  • The second event was on April 4, 2019, at the Falstaff Community Centre.
  • The third event was on December 11, 2019, at the Falstaff Community Centre.

Study Links