In May 2000, the groundwater supplying the municipal well for Walkerton Ontario became contaminated with E. coli. As a result of the failure of multiple protection measures, seven people died and thousands became ill after drinking the contaminated water. It was the catalyst for a public inquiry led by Justice Dennis O'Connor. Justice O'Connor made 121 recommendations to better protect sources of drinking water, including source water protection.

Protecting our drinking water is not a one-step process, Ontario uses a multi-barrier approach to protecting municipal drinking water 'from source to tap'. Source water protection is the first step in the multi-barrier approach, followed by effective water treatment, operator training, testing and distribution before the water reaches your tap. By ensuring that proper protection is in place at each stage of this process, the likelihood of water contamination is reduced.

In response to Justice O'Connor's recommendation for a multi-barrier approach to providing safe drinking water, the Ontario government pass the Clean Water Act, 2006, and funded a drinking water source protection initiative, as well as strengthening existing legislation.

Cataraqui Conservation's Full Authority Board, known under the Clean Water Act as the "Source Protection Authority", supported the formation of the Cataraqui Source Protection Committee. The Committee led the technical and planning work necessary to put together the Cataraqui Source Protection Plan.

One of the first tasks of the Cataraqui Source Protection Committee was to prepare a document called a terms of reference under the Clean Water Act, which identified the work plan for the source protection planning process, including research and planning, assigning roles and responsibilities and establishing timelines and funding estimates.

The Assessment Report identified areas where drinking water sources are vulnerable to contamination or overuse, and prioritized drinking water issues and drinking water threats within those vulnerable areas. The Assessment Report was prepared in accordance with detailed technical rules set out by the Ministry of the Environment and Climate Change. The report was approved by the Ministry in 2011. The content of the Assessment Report was used to support the development of a Cataraqui Source Protection Plan.

The Cataraqui Source Protection Plan (the Plan) is a locally developed plan of action to keep sources of drinking water clean and plentiful. The Plan includes requirements or recommendations to reduce the risk of pollution near drinking water supplies. The Cataraqui Source Protection Plan focuses on protecting sources of drinking water from systems that provide drinking water to communities and certain types of residential buildings (also known as municipal residential drinking water supplies), and also includes polices for the entire Cataraqui Source Protection Area where the groundwater is vulnerable to contamination or overuse. The Cataraqui Source Protection Plan received approval from the Minister of the Environment and Climate Change, the Honourable Glen Murray, on November 26, 2014.

The Cataraqui Source Protection Plan came into effect on April 1, 2015. Implementation of the Plan is being carried out cooperatively amongst implementing bodies, including municipalities, local health units, provincial ministries, Cataraqui Conservation, businesses and others.

The Act currently identifies 22 drinking water threats. 20 relate to quality and two relate to quantity. The Table of Drinking Water Threats highlight the prescribed threats and the circumstances at which they would be considered low, moderate or significant threats.

Along with the prescribed threats and circumstances associated with them, for a threat to be considered significant, it must be associated with a certain level of risk which is tied to the location of the activity and its proximity to the drinking water well or intake. Significant threats are generally located in closer proximity to a well or intake and invoke high risk rating threats and circumstances.