Municipal water supplies

• Groundwater: About 69 per cent of municipal water comes from groundwater wells. Municipalities operate close to 200 wells. The Region of Waterloo (100 wells) and the City of Guelph (21 wells) are among the largest groundwater-based systems in Canada.
• Rivers: About 28 per cent of our water comes from the Grand and Eramosa rivers. The City of Guelph and Region of Waterloo get some of their water from the river system. The City of Brantford and Six Nations get all of their water from the Grand River.
• Great Lakes: About three per cent comes from the Great Lakes. Intakes at Dunnville and Nanticoke serve parts of Haldimand County and the Mississaugas of the Credit Territory. Water for the communities of Cayuga and Caledonia in Haldimand County comes from the City of Hamilton.

We operate seven reservoirs that are used to maintain minimum flows in the river. Water is stored in the reservoirs during the spring and then released gradually through the summer and fall to meet flow targets. This is called flow augmentation. It ensures there is enough water of reliable quality for municipal water systems that get some or all of their water from the Grand River.

More information is available on our river and stream flow and reservoir data pages.

Municipalities are responsible to the Ontario Ministry of the Environment and Climate Change for the safe operation of their systems.

The province has passed two key laws to oversee the process:

1. Safe Drinking Water Act: The act and related regulations spell out how municipalities must distribute, treat and test their water.
2. Clean Water Act: This act and related regulations oversee the Drinking Water Source Protection Program, which protects the quality and quantity of water in the ground, rivers and lakes.

Municipalities publish annual reports on the operation of their systems. You can find these reports on municipal websites.

We have carried out several studies to assess the current state of the sources of municipal water and the potential impact of growth, drought and other stresses in the future. Visit the water budget studies page on the Lake Erie Source Protection Area website to view the studies.

Municipal programs encourage water conservation to reduce the demand for water. These include restrictions on outdoor water use and incentive programs to encourage homeowners to purchase water efficient appliances. Go to municipal websites to learn more about their programs.

The Municipal Water Demand Management Primers describe steps municipalities and their residents can take to reduce municipal water demand.

The Grand River Watershed Water Management Plan addresses issues relating to municipal water supplies including water conservation and future water needs.