Drinking Water Source Protection

Drinking water source protection is about safeguarding both the quality and the quantity of our municipal drinking water sources, now and into the future.

What Is Drinking Water Source Protection?

Our municipal drinking water comes from lakes, rivers, streams or underground sources (aquifers) located across the province of Ontario. All of these sources of water are linked in a watershed through the water cycle. Drinking water source protection is about safeguarding both the quality and the quantity of these municipal drinking water sources, now and into the future.

The Clean Water Act, 2006 introduced a new level of protection for Ontario’s drinking water resources — one that focuses on protecting water before it enters the drinking water treatment system. The Act establishes a locally driven, science-based, multi-stakeholder process to protect municipal residential drinking water sources and designated private drinking water sources.

Drinking water source protection involves identifying threats to municipal drinking water sources, assessing the significance of each threat, taking action to reduce or eliminate the threat, and monitoring progress.

TRCA source water protection water treatment aerial view

Source Protection Plans

The Clean Water Act, 2006 and associated regulations established source protection areas and regions across Ontario for which drinking water source protection were to be created. Each drinking water source protection plan is based upon an understanding of water quantity, quality, processes, threats and possible solutions for the watersheds in the region.

The best way to protect sources of water is on a watershed basis, because water flows across traditional municipal boundaries. Conservation authorities are organized on a watershed basis, and are recognized for their watershed management expertise, as well as their connections to local communities. As a result, they have played a key role in coordinating of the drinking water source protection planning process, which has involved extensive participation by municipalities, community organizations, industries and residents.

Source Protection Planning in Toronto and Region

Toronto and Region Conservation has worked with Credit Valley Conservation (CVC) and Central Lake Ontario Conservation Authority (CLOCA) to lead development of the source protection plan for the CTC Source Protection Region. Comprising three Source Protection Areas (Credit Valley, Toronto and Region and Central Lake Ontario), this region spans more than 10,000 square kilometres and includes 25 municipalities.

The Source Protection Plan for the CTC Source Protection Region came into effect on December 31, 2015.




We all have a responsibility to safeguard human health by ensuring that current and future sources of municipal drinking water are protected from potential contamination and depletion. Protecting water at its source is the first step in ensuring that every Ontarian has access to safe drinking water — part of a multi-barrier preventive approach.