Visualize historical trends
Select a Water Station and Substance to View Data Trends for the Past 20 Years (Data availability may vary).
Generate Heat Map
Select a year and indicator to generate watershed level heat maps showing how water quality is expected to increase, decrease, or remain stable across watersheds and regions over time.
Historical data and trends are derived from TRCA's Regional Watershed Monitoring Program (up to 2022) and CLOCA's Open Data (up to 2023).
Substance/Chemical
The Confidence Score, which ranges from 0% to 100%, indicates how reliable each model prediction is based on historical data and insights. It is calculated through a multi-step process, incorporating statistical analysis, feature importance, and machine learning predictions. Scores below 40% are considered Low, while scores above 70% are considered to be High. Higher scores indicate greater confidence in the model’s forecast, helping support informed decision-making and scenario analysis.
Threshold values for Total Phosphorus are based on
PWQO
water quality guidelines.
Applies to Rivers and Streams.
The Provincial Water Quality Objectives
(
PWQO
) are Ontario’s water quality guidelines established to protect aquatic life, recreational water use, and drinking water sources. Developed by the Ontario Ministry of the Environment, Conservation and Parks (MECP), these objectives set concentration limits for various contaminants to maintain water quality and ecosystem health.
