The Windsor-Essex County Health Unit (WECHU) is working to expand its beach water safety program by introducing daily water quality forecasts, but the plan still requires support from local municipalities.
If implemented, the new system would function like a weather forecast — but for water quality.
Rather than waiting for weekly lab test results, beachgoers would be able to check a webpage for daily predictions on whether swimming conditions are likely safe.
The model would analyze past water quality trends alongside real-time environmental factors — like rainfall, wave height and temperature —to estimate conditions each day.
Right now, WECHU collects water samples once a week at eight local beaches, sending them to a Public Health Ontario lab in London.
With results taking 24 to 48 hours to process, water conditions may shift before the data is even made public.
“We know a sample on one day is only representative of what’s happening on that day,” said Kristy McBeth, Senior Director of Public Health Programs at WECHU.
The predictive model would offer more up-to-date information by factoring in trends from previous years and current conditions.
“Forecasting is... not necessarily testing reliant, it’s data reliant,” McBeth explained.
“We have years and years of really great rich data around this program that we can use and combine that with things like weather temperature and then current water testing conditions like turbidity, as an example.”
But, she stressed, these predictions aren’t guarantees — they’re estimates based on trends and current conditions.
The system won’t determine beach closures, which will still be based on weekly E. coli test results.
Instead, the daily forecasts are meant to help swimmers make more informed decisions before heading to the beach.
“On a day-to-day basis, we can give swimmers and beachgoers a ‘we expect today is likely safe for swimming’ or ‘it’s likely not,’” McBeth said.
Before the new system can launch, municipalities must decide whether to participate.
WECHU plans to present the model to local councils, and not every beach may be included in the forecast.
“The model will be presented to all municipalities with opportunities to participate at any of the eight currently tested beaches,” McBeth said.
“Even if that predictive model isn’t necessarily available on a day-to-day basis for every beach, the weekly testing will continue to be there.”
If approved, the forecasts would launch in May 2025, alongside the annual beach water testing program that typically kicks off around the Victoria Day long weekend.
