The Ontario Ministry of Environment, Conservation and Parks (MECP) Source Water Protection program facilitates the creation of watershed-based protection plans that act as the first line of defense in a multi-barrier approach to protecting drinking water.

The program was created as a result of the province’s 2006 Clean Water Act, which requires the assessment of threats to sources of drinking water and the implementation of protection plans. This program covers both groundwater and surface water sources. To comply with this requirement, Ontario established source protection areas based on natural watershed boundaries and created local multi-stakeholder source protection committees to engage in planning efforts for each area. Source protection authorities provide local program delivery. Source protection plans have been developed by these committees for all source protection areas and received the official approval of MECP. Copies of these plans as well as other locally-focused resources related to source water protection planning and implementation are available online. These watershed-based plans are implemented mainly by provincial and municipal levels of government. Plan policies require actions to reduce, eliminate or manage identified risks. Examples of these actions range from changing land uses, to prohibiting or restricting activities that pose a threat to source water or setting up septic system inspection programs through local health departments.