The Ontario Ministry of the Environment is responsible for the protection of drinking water and fresh water resources in Ontario.
The Ministry of Natural Resources (MNR) is responsible for management of water resources.
Conservation Ontario is a non-governmental organization representing 36 Conservation Authorities which provides local watershed management of water resources. Links to the 36 Conservation Authorities websites are provided on the Ontario's 36 Conservation Authorities webpage.
Water flow in watercourses, water levels in lakes and reservoirs and climate data are monitored and analysed by the MNR Surface Water Monitoring Centre, and are shared with a variety of partners and other water resource managers through the Surface Water Monitoring Centre Extranet. Access to the site is restricted to those individuals, agencies, organizations and institutions that have an identified operational need for water management data, and are responsible for water management in Ontario.
Many of the Conservation Authorities such as Grand River provide access to real time data on their websites.
The Ministry of Natural Resources provides flood information and warnings on a province wide basis. Information is available at their Emergency Management Current Flood Message webpage.
Ontario's Conservation Authorities (CA) provide local flood messaging for their areas of responsibility. The CA's own and operate infrastructure and operate flood control programs to minimize flood risk. The CA's roles and responsibilities for flood management are described on the Conservation Ontario's Conservation Authority Flood Management webpage.
Ontario has prepared a response plan, Ontario Low Water Response, to ensure preparedness for low water conditions.
Information on low flows (condition reports and maps) is available at the Ministry of Natural Resources' Low Water Conditions Page webpage.
There are three primary watersheds in the Province: the Great Lakes, Nelson River and Hudson Bay. These are subdivided into 17 secondary sub-basins, then further into 144 tertiary sub-sub-basins and then again into quaternary watersheds. Further information is available on the MNR Water Resources webpage.
Access to various water related documents are available from the following webpages: