Residents in Southwood Lakes are being asked to avoid the subdivision's ponds.
In a statement Saturday, the City of Windsor says it has detected the presence of blue-green algae in the water. Blue-green algae contain toxins that can be dangerous to the health of humans and especially animals.
The neighbourhood east of Howard Avenue off North Talbot Road has several large man-made ponds.
According to the city, those ponds were created for storm water and aren't for recreation, but they're still warning residents to stay out of the water and keep their pets away as well.
The city is also asking homeowners to restrict fertilizer use as it contributes to the growth of the algae.
Officials say they'll continue to monitor the situation and hope rain and cooler temperatures helps clear the ponds.