Water use and supply project

In this Section:

• Background
• Product Examples
• Additional Resources

Background

The Water Use and Supply Project was initiated to support improved management of surface and groundwater resources in the Canadian sub-watersheds of the Great Lakes, Ottawa River, and upper St. Lawrence River within Ontario. The project was active between 2000 and 2008 and focused on summarizing available baseline information needed to support management efforts.

Product Examples

Throughout the Water Use and Supply Project, considerable effort was focused on identifying relevant metrics (descriptors) of water supply, water use, and ecological requirements on a watershed scale. These metrics were a way to assess a particular water resource aspect of a watershed. The intent was to use metrics that could be consistently applied to watersheds of the Great Lakes, St. Lawrence River, and Ottawa River within the Province of Ontario to support assessment of the relative differences between the watersheds. The Water Use and Supply Project metrics are general in nature and are meant to provide an overview assessment of the relative differences in conditions between watersheds. The work complements detailed investigations that may be ongoing within particular watersheds of the basin. The metrics were developed under three main themes including Water Supply (quantity), Water Use, and Ecological Requirements.

Particular attention was paid to developing metrics based on widely available data that could be applied across the study area. Where limited data existed (e.g. groundwater conditions), Water Use and Supply Project members attempted to utilize related efforts to support metric development. The Water Use and Supply Project effort provides a starting point for refinement and development of additional metrics in the future as resources and data become available.

The primary products of the Water Use and Supply Project are map layers where individual watersheds are represented for the metric of interest. An example map layer is provided showing average annual discharge for the individual watersheds within the study area. The values were calculated by Dr. Andrew Piggott (NWRI) using stream flow data from the Water Survey of Canada. In this example, the watershed boundaries represent the area between two monitoring stations in the hydrometric data (HYDAT) network.

Various map layers were developed within the main themes of water supply (quantity), water use, and ecological requirements. For water supply, various stream flow statistics were generated from historical monitoring data to represent surface water conditions during both high and low flow conditions (e.g. 7Q10 per unit area (a low flow statistic) and Q10 per unit area (a high flow statistic)). Groundwater conditions were also considered including Base Flow Index (BFI), Base Flow Recession (BFR), and estimated recharge.

The water use category represents human requirements for water within the Water Use and Supply Project study area. The Province of Ontario summarizes water use at the tertiary watershed level as part of their reporting to the Great Lakes Commission. Water use metrics included public water use, self supply domestic water use, irrigation water use, and livestock water use.

In addition to total water use estimates, the Water Use and Supply Project has also represented certain categories based on the estimated consumptive water use (the total water use multiplied by a consumptive use coefficient). Consumptive water use is the water that is not returned to the watershed from which it is taken (an example might be irrigation water that is evaporated and removed from the watershed). Consumptive use coefficients vary within jurisdictions of the Great Lakes Basin but they do help to represent a general estimate of how much water is actually consumed in a particular user group.

Within the Water Use and Supply Project, ecological requirements were considered as the amount of water needed to support particular ecosystem functions. Understanding ecological requirements is an ongoing area of research throughout the world. Challenges remain in identifying ecological impacts that occur due to changes in water supply as opposed to other watershed stressors. From a Water Use and Supply Project perspective, the metrics are largely descriptive in nature and require further testing and refinement to understand their full implications for understanding the complex interaction between water supply and ecological requirements. Metrics tested for watershed reporting within Water Use and Supply Project were related to fish populations, wetland conditions, and water quality.

Additional Resources

For further information on the activities and results of the Water Use and Supply Project, please contact Environmet Canada's Ontario office.

In addition to the work of the Water Use and Supply Project, the following resources may be of interest with regards to available data and information on aspects of water supply and use in the Great Lakes basin.

Some of the following hyperlinks are to sites of organizations or other entities that are not subject to the Official Languages Act. The material found there is therefore in the language(s) used by the sites in question.

Environment Canada

Water Supply:

• The Water Survey of Canada undertakes surface water monitoring across the country and provides access to past data.
• The Meteorological Service of Canada undertakes precipitation monitoring across the country and provides access to past data.

External to Environment Canada

Water Use:

• The Great Lakes Commission undertakes water use reporting for states and provinces bordering the Great Lakes.
• Statistics Canada reports on various aspects of water use by Canadians.

Ecological Requirements:

• Current research is being done in support of the National Agri-Environmental Standards Initiative regarding ecological flow requirements.

Overall Water Availability Assessments:

• Within the Province of Ontario, Conservation Authorities are currently undertaking water budgets as part of the Source Water Protection initiative. Detailed water supply and use information will be made available through the Conservation Authorities in the coming years.
• The United States Geological Survey (USGS) is undertaking a pilot project aimed at assessing water availability in the U.S. portion of the Great Lakes Basin.