Toronto beach water quality predictions

Released: June 2022 

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Artificial intelligence predictive modelling (AIPM) is a system used by Toronto Public Health (TPH) to forecast water quality at two beaches.

The system uses a series of calculations based on historical data and metrics such as rainfall, temperature and wind direction. It also pulls real-time meteorological and hydrological data. 

AIPM was adopted by the authority early summer 2022, but quickly came under pressure as it appears to have repeatedly allowed contaminated beaches to remain open. 


The accuracy of the system was quickly called into question by water advocacy group Swim Drink Fish, which discovered that waters off the beaches tested high for E.coli using traditional means had been marked safe by the new system over 30 times

Per the Toronto Star, TPH responded by saying 'While AIPM is not expected to be 100 per cent accurate in assessing water quality, it presents a significant improvement over test results using the traditional means for assessing microbial water quality.'


Swim Drink Fish argue more transparency is needed from the Toronto Health Board if the model is to remain so that beachgoers can make educated decisions regarding their own health and safety. 

Yet they were poorly guided. According to The Information, TPH officials 'did not respond to a question about whether officials ever overrode the model’s forecast. But data published by the city show that the posted swimming flags at the two beaches never differed from the model’s predictions.'

Operator: Toronto Public Health
Developer: Cann Forecast
Country: Canada
Sector: Govt - health
Purpose: Predict water quality
Technology: Prediction algorithm
Issue: Accuracy/reliability; Safety
Transparency: Governance; Black box


Research, advocacy

News, commentary, analysis

Page info
Type: System
Published: December 2022