Whitby Water Supply Plant Expansion

What is this Project?

The Regional Municipality of Durham (the Region) is proceeding with an expansion of the Whitby Water Supply Plant (WSP) at 301 Water Street in Whitby. Supporting infrastructure will be added on the north side of the road at 270 Water Street, including but not limited to an Energy Centre, a secured staff parking area, a shared public parking lot as well as a construction laydown and staging area.

The expansion of the Whitby WSP is planned to be implemented over five contracts:

Contract 1 - Whitby WSP Industrial Raw Water Pumping Station Relocation and Outfall Chamber Construction

This project entails the installing of new industrial raw water pumps within the Whitby Water Supply Plant at 301 Water Street, the construction of a new outfall chamber, as well as the replacement of chlorine solution/water sampling lines for the raw water well intake pipe. This project is in its final stages of completion.

Contract 2 - Whitby WSP Existing Plant Rehabilitation and Lake Ontario Water Quality Monitoring Instrumentation system

This project includes the rehabilitation of the existing Whitby Water Supply Plant filters, backwash pumps and chlorinators. In addition, this project includes the installation of a Lake Ontario Water Quality Monitoring Instrumentation System. This project is estimated to be tendered in 2026.

Contract 3A/B - Site Preparation, Energy Centre and Demolition Works

This Contract is intended to be an enabling works Contract for the main water supply Whitby Water Supply Plant, Plant Expansion Contract (Contract 4). The scope of Contract 3 includes but is not limited to the following:

  • Clearing and grading of the 270 Water Street site for preparation as a construction staging and laydown area for Contracts 3 and 4.
  • Establishment of a temporary public parking lot on the 270 Water Street property.
  • Construction of the Region's Energy Centre, including electrical power supply infrastructure for the existing and future Plant and emergency back-up power infrastructure.
  • Construction of supporting infrastructure for the development of the 270 Water Street site as well as the future Whitby Water Supply Plant expansion, including but not limited to, a new major storm conveyance twin box culvert system and the replacement of Regional local watermain and sanitary sewers on Water Street.
  • Erection of construction fencing and gates around the Region's 301 Water Street property.
  • Demolition of the existing Facilities Management Ancillary Building, electrical substation and abandoned clear well on the 289 Water Street site.

Contract 4 - Whitby WSP Expansion

This is the planned main Whitby Water Supply Plant Expansion Contract.

Contract 5 - Site and Public Realm Improvements

This Contract is intended to implement the public realm improvements on both the 301 Water Street site as well as the ultimate condition for the 270 Water Street site. The scope of work for this contract is not finalized and will be finalized in collaboration with the Town of Whitby.

Municipal Class Environmental Assessment (Class EA)

In 2005, the Region completed a Class EA study that recommended an expansion of the Whitby WSP. The study evaluated on-site and off-site WSP expansion options and concluded that the preferred solution was to expand the Whitby WSP on the north side of Water Street. Investigations completed during the preliminary design phase on the property concluded that the site is not suitable for the construction of a water treatment plant facility. A Class EA Addendum was subsequently initiated by the Region in 2018 to assess alternative options for expanding water treatment capacity. The preferred alternative identified by the Class EA Addendum was to expand the existing water supply plant by constructing a second plant on the same property as the existing plant at 301 Water Street.

Following early design discussions and a collaborative design charrette with the Town of Whitby, refinements were made to the proposed expansion layout for the Whitby WSP to minimize impacts to the Whitby waterfront and to address site constraints associated with constructing an expansion on an existing developed site. These refinements led to the initiation of an additional Class EA Addendum in 2021, supported by extensive stakeholder engagement and a water treatment technology selection exercise.

The additional EA Addendum was completed in April 2023 and confirmed a revised preferred plan that focused the Whitby WSP expansion on the southerly 301 Water Street property. This plan included supporting infrastructure, including an energy centre, parking and an interim construction staging/laydown area on the north side of Water Street.

Visit the Documents Section for a complete list of Class EA documents.

What's Happening

Field work is currently being completed on the Whitby WSP property at 301 Water Street in Whitby until the end of 2025.

Stay up to date. Check back for more information about what's happening as part of the Whitby Water Supply Plant expansion project.


Get in touch

For more information, to direct a question to the project team or to be added to the mailing list for the Whitby Water Supply Plan expansion project, please email whitbywspproject@durham.ca.

What is this Project?

The Regional Municipality of Durham (the Region) is proceeding with an expansion of the Whitby Water Supply Plant (WSP) at 301 Water Street in Whitby. Supporting infrastructure will be added on the north side of the road at 270 Water Street, including but not limited to an Energy Centre, a secured staff parking area, a shared public parking lot as well as a construction laydown and staging area.

The expansion of the Whitby WSP is planned to be implemented over five contracts:

Contract 1 - Whitby WSP Industrial Raw Water Pumping Station Relocation and Outfall Chamber Construction

This project entails the installing of new industrial raw water pumps within the Whitby Water Supply Plant at 301 Water Street, the construction of a new outfall chamber, as well as the replacement of chlorine solution/water sampling lines for the raw water well intake pipe. This project is in its final stages of completion.

Contract 2 - Whitby WSP Existing Plant Rehabilitation and Lake Ontario Water Quality Monitoring Instrumentation system

This project includes the rehabilitation of the existing Whitby Water Supply Plant filters, backwash pumps and chlorinators. In addition, this project includes the installation of a Lake Ontario Water Quality Monitoring Instrumentation System. This project is estimated to be tendered in 2026.

Contract 3A/B - Site Preparation, Energy Centre and Demolition Works

This Contract is intended to be an enabling works Contract for the main water supply Whitby Water Supply Plant, Plant Expansion Contract (Contract 4). The scope of Contract 3 includes but is not limited to the following:

  • Clearing and grading of the 270 Water Street site for preparation as a construction staging and laydown area for Contracts 3 and 4.
  • Establishment of a temporary public parking lot on the 270 Water Street property.
  • Construction of the Region's Energy Centre, including electrical power supply infrastructure for the existing and future Plant and emergency back-up power infrastructure.
  • Construction of supporting infrastructure for the development of the 270 Water Street site as well as the future Whitby Water Supply Plant expansion, including but not limited to, a new major storm conveyance twin box culvert system and the replacement of Regional local watermain and sanitary sewers on Water Street.
  • Erection of construction fencing and gates around the Region's 301 Water Street property.
  • Demolition of the existing Facilities Management Ancillary Building, electrical substation and abandoned clear well on the 289 Water Street site.

Contract 4 - Whitby WSP Expansion

This is the planned main Whitby Water Supply Plant Expansion Contract.

Contract 5 - Site and Public Realm Improvements

This Contract is intended to implement the public realm improvements on both the 301 Water Street site as well as the ultimate condition for the 270 Water Street site. The scope of work for this contract is not finalized and will be finalized in collaboration with the Town of Whitby.

Municipal Class Environmental Assessment (Class EA)

In 2005, the Region completed a Class EA study that recommended an expansion of the Whitby WSP. The study evaluated on-site and off-site WSP expansion options and concluded that the preferred solution was to expand the Whitby WSP on the north side of Water Street. Investigations completed during the preliminary design phase on the property concluded that the site is not suitable for the construction of a water treatment plant facility. A Class EA Addendum was subsequently initiated by the Region in 2018 to assess alternative options for expanding water treatment capacity. The preferred alternative identified by the Class EA Addendum was to expand the existing water supply plant by constructing a second plant on the same property as the existing plant at 301 Water Street.

Following early design discussions and a collaborative design charrette with the Town of Whitby, refinements were made to the proposed expansion layout for the Whitby WSP to minimize impacts to the Whitby waterfront and to address site constraints associated with constructing an expansion on an existing developed site. These refinements led to the initiation of an additional Class EA Addendum in 2021, supported by extensive stakeholder engagement and a water treatment technology selection exercise.

The additional EA Addendum was completed in April 2023 and confirmed a revised preferred plan that focused the Whitby WSP expansion on the southerly 301 Water Street property. This plan included supporting infrastructure, including an energy centre, parking and an interim construction staging/laydown area on the north side of Water Street.

Visit the Documents Section for a complete list of Class EA documents.

What's Happening

Field work is currently being completed on the Whitby WSP property at 301 Water Street in Whitby until the end of 2025.

Stay up to date. Check back for more information about what's happening as part of the Whitby Water Supply Plant expansion project.


Get in touch

For more information, to direct a question to the project team or to be added to the mailing list for the Whitby Water Supply Plan expansion project, please email whitbywspproject@durham.ca.

Page last updated: 07 Oct 2025, 10:35 AM