What Is An Assessment Report?

What Is An Assessment Report?

To protect our drinking water, we need to understand what’s going on in the surrounding watershed —¬†both above and below ground. An Assessment Report looks at all of the factors influencing the quality and quantity of water within a watershed.

A key requirement of the Clean Water Act, 2006, an Assessment Report is the scientific backbone on which policies rest. It includes information such as:

  • The physical characteristics of the land in the watershed
  • Land use
  • The location of drinking water sources
  • How much water is being used and how much is available for future uses
  • Where vulnerable water sources are located
  • Potential threats that may compromise drinking water sources, whether through contamination or overuse

The CTC Source Protection Committee was responsible for the development of Assessment Reports for each of the Source Protection Areas within the CTC Source Protection Region:

Credit Valley Source Protection Area

Toronto and Region Source Protection Area

Central Lake Ontario Source Protection Area

These Assessment Reports are based on detailed technical studies, and underwent a rigorous peer review process. They are considered “living documents,” subject to ongoing updates and amendments as new information becomes available.

This brochure provides a comprehensive overview of the Assessment Reports and Source Protection Plan.



In November 2009, the Ministry of the Environment issued amended technical rules to guide the development of Assessment Reports across Ontario: