Updating the Water Quality in Canadian Rivers Indicator: Reporting Trends and Improving Reporting

Background The Canadian Environmental Sustainability Indicators (CESI) Program has a mandate to report to Canadians on the state of the environment and to track progress towards the goals and targets of the Federal Sustainable Development Strategy. In 2005, CESI reported the first overall picture of freshwater quality for Canada using a histogram built on scores calculated using the Canadian Council of Ministers of the Environment’s Water Quality Index. After 10 years of reporting the Freshwater Quality Indicator (WQI), Environment Canada and partners are reviewing its methods and presentation. To be useful, a good indicator should be able to assess trends, compare places and situations, provide simplified data, monitor progress, and identify and signal emerging issues. While the data underlying the WQI includes numbers to report these elements, the information shared with the public does not cover the full range of reporting possibilities. For example, changes in the WQI through time are calculated by assessing changes in index scores between the first year and most recent reporting period using estimates of the variability of the score calculated by bootstrapping. While the tool evaluates change in the index between two reporting periods, it is inconclusive for the majority of sites. Objective The objective of this project is to develop a method to report on changes in freshwater quality in Canada over the last 11 years and to provide options to improve the WQI reporting in a manner that will maximize the information contained in the indicator for public reporting on the web.