After recent mild temperatures, the Essex Region Conservation Authority says the ground is already saturated.
Environment Canada predicts up to 25 mm of rain on Thursday, so there could be flooding across Windsor-Essex.
The authority issued a watershed condition statement after monitoring rainfall so far. As of 8 a.m., it said the northern end of Essex County had received 14 mm of rain, while slightly more has fallen in southern parts. Many of the smaller watercourses are filling up fast.
All the water increases the risk of basement flooding, but the City of Windsor has tips for homeowners who wish to protect their property.
It recommends clearing catch basins and eavestroughs of leaves and debris. Disconnect your home's downspouts from the municipal drainage system. Homeowners should make sure sump pumps and backwater valves are working and check the grading around the foundation. If it is sloped away from exterior walls, rainwater can naturally drain away from your house.
For homeowners who don't have a sump pump or backwater valve, or need their downspout disconnected, the city offers the Basement Flooding Protection Subsidy Program to pay for up to $2,800 of those costs.
The city also provides eel service to clear sewer laterals up to three times within a 24-month period. Homeowners can request the service by calling 311.
Environment Canada said the rain should move out of the region Thursday night.