The Assessment Reports for each SPA will be composed of five technical elements.  These technical elements include:

• Watershed Characterization
• Water Budgets and Water Quantity Threats Assessment
• Groundwater Vulnerability
• Surface Water Vulnerability
• Threats and Issues - Water Quality Threats Assessment

Learn More about Assessment Reports

The Updated/Amended Assessment Reports for the CTC Source Protection Region have been submitted to the Ministry of the Environment for their approval.

These Updated Reports contain new information about potential threats to Lake Ontario Drinking Water Sources as well as new vulnerable areas in the Halton Hills and Orangeville areas.
Note: these files are large and may take a long time to download, especially from dial-up internet. We would be happy to send you an electronic copy on CD, at your request to This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Updated Assessment Report: Credt Valley Source Protection Area

Part 1 (Chapters 1-3)
Part 2 (Chapters 4-7

Appendix: Updated Assessment Report: Credit Valley Source Protection Area

Updated Assessment Report: Toronto and Region Source Protection Area

Updated Assessment Report: Toronto and Region Source Protection Area

Appendix: Updated Assessment Report: Toronto and Region Source Proteciton Area

Updated Assessment Report: Central Lake Ontario Source Protection Area

Amended Proposed Assessment Report: Central Lake Ontario Source Protection Area

Appendix: Updated Assessment Report: Central Lake Ontario Source Protection Area

The Draft Updated Proposed Assessment Reports for the CTC Source Protection Region are now available online and by request for review and comment. The comment period runs from June 17, 2011 to July 18, 2011

These Updated Reports contain new information about potential threats to Lake Ontario Drinking Water Sources as well as new vulnerable areas in the Halton Hills and Orangeville areas.

Draft Updated Proposed Assessment Report: Credt Valley Source Protection Area

Draft Updated Proposed Assessment Report: Toronto and Region Source Protection Area

Draft Updated Proposed Assessment Report: Central Lake Ontario Source Protection Area

The Source Protection Committee will consider any comments you make. Comments should be sent to  Susan Self, Chair, CTC Source Protection Committee  by July 18, 2011 at 5 Shoreham Drive, Downsview ON M3N 1S4, by fax at 416-667-6278 or by email to This e-mail address is being protected from spambots. You need JavaScript enabled to view it . Requests for electronic copies can be made to This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Credit Valley Source Protection Area Assessment Report

The Credit Valley Source Protection Authority (CVSPA) is pleased to anounce that on Tuesday, December 21, 2010, the Proposed Assessment Report: CVSPA was submitted to the Ministry of the Environment for approval. The Proposed Assessment Report: CVSPA will be updated with Intake Protection Zone 3 (IPZ3) work, tier 3 water budget analysis and other updates in the summer of 2011. 

The Proposed Assessment Report identifies the location and nature of possible risks to sources of municipal drinking water and non-municipal systems in the Credit Valley Source Protection Area.  These risks include activities that are adversely impacting, or could impact, drinking water quality or quantity.  The CTC Source Protection Committee is continuing to work to identify possible threats to Lake Ontario drinking water sources and these findings will be presented in an updated Assessment Report anticipated to be released mid-2011.

Go to the CVPSA Assessment Report

Toronto and Region Source Protection Area Assessment Report

The Toronto and Region Source Protection Authority (TRSPA) is pleased to anounce that on Tuesday, December 21, 2010, the Proposed Assessment Report: TRSPA was submitted to the Ministry of the Environment for approval. The Proposed Assessment Report: TRSPA will be updated with Intake Protection Zone 3 (IPZ3) work, tier 3 water budget analysis and other updates in the summer of 2011. 

The Proposed Assessment Report identifies the location and nature of possible risks to sources of municipal drinking water and non-municipal systems in the Toronto and Region Source Protection Area.  These risks include activities that are adversely impacting, or could impact, drinking water quality or quantity.  The CTC Source Protection Committee is continuing to work to identify possible threats to Lake Ontario drinking water sources and these findings will be presented in an updated Assessment Report anticipated to be released mid-2011.

Go to the TRSPA Assessment Report

Central Lake Ontario Source Protection Area Assessment Report

The Central Lake Ontario Source Protection Authority (CLOSPA) is pleased to anounce that on Tuesday, August 17th, the Proposed Assessment Report: CLOSPA was submitted to the Ministry of the Environment for approval. The Proposed Assessment Report: CLOSPA will be updated with Intake Protection Zone 3 (IPZ3) work in the summer of 2011. This work with  identify drinking water threats to Lake Ontario based drinking water sources.

The Proposed Assessment Report identifies the location and nature of possible risks to sources of municipal drinking water and non-municipal systems in the Central Lake Ontario watershed.  These risks include activities that are adversely impacting, or could impact, drinking water quality or quantity.  The CTC Source Protection Committee is continuing to work to identify possible threats to Lake Ontario drinking water sources and these findings will be presented in an updated Assessment Report anticipated to be released mid-2011. 

We encourage you to read the Executive Summary or Full Report online.

The report is also available on compact disc by request to This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Technical documents used to prepare the Assessment Reports are made available at the links below:

Technical Documents - Credit Valley Source Protection Area
Technical Documents - Toronto and Region Source Protection Area
Technical Documents - Central Lake Ontario Source Protection Area

The Assessment Reports for the CTC Source Protection Areas potential threats to both water quality and water supplies for each of the CTC watersheds. This scientific work is well underway with experts in the field studying water quality, water quantity and the potential threats to these water supplies. 

On November 18, 2009 the Ministry of the Environment released amended technical rules to guide the development of Assessment Reports across Ontario.  These amended technical rules are being used to develop the Assessment Reports in the CTC region and are composed of three documents which include:

Technical Rules: Assessment Report

Mapping Symbology for the Clean Water Act

Tables of Drinking Water Threats