A study has completed to determine the contributing factors for surface and basement flooding in the City of Toronto and recommend solutions to improve the City’s sewer system and overland drainage routes in order to mitigate flooding problems.

Study Area 45 location in the Black Creek and Highway 401 (north and south) area has experienced recurring basement and surface flooding during extreme storms in the past. This area consisted of several underground sewer systems in the area roughly bounded by Steeles Avenue West, St Clair Avenue West, Highway 400 and Keele Street.

Following consultation with agencies, City Divisions and the public, the following are the study recommendations:

  • 234 new and upsized storm and sanitary sewers
  • Section of large diameter storm and sanitary sewer used for temporary, in-line storage during heavy rain storms
  • Sewer outfall improvements (stormwater discharge outlets to creeks)
  • Catchbasin management


The study was carried out following the requirements for Schedule B projects under the Municipal Class EA. The Project File has been placed on public record for a 45-day review period starting July 29, 2021 and ending September 17, 2021.

The Executive Summary is available for review at toronto.ca/bf45 or by contacting the City staff listed on this notice if you would like to receive the full Project File.

Interested persons may provide written comments to our project team by September 17, 2021.

All comments and concerns should be addressed to City staff listed on this notice and we will attempt to find a mutually acceptable resolution.

Notice Study Completion 2021 July to September

BF45 solutions map
BF45 solutions map

Study Area 45 consists of several individual sewersheds distributed in portions of Ward 5, York South-Weston, Ward 6, York Centre, Ward 7, Humber River-Black Creek & Ward 9, Davenport. These sewersheds are roughly located in the area bounded by Steeles Avenue West to the north, St Clair Avenue West to the south, Highway 400 to the west, and Keele Street to the east.

In December 2019, there was a drop-in event to review, discuss and provide community feedback on the recommended solutions to reduce the risk of basement and surface flooding and improve stormwater runoff quality in the study area.

The Study was completed in July 2021.  Public Review of the Project File was provided online and upon request in hard copies.  Please see main page for more information.

What is a Class Environmental Assessment?

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.