Flooding in Chatham-Kent: The Thames in February, Lake Erie All Year and Basements on Flat Clay

Three kinds of water on flat land

River flooding announces itself: the Lower Thames Valley Conservation Authority issues warnings, the Thames rises at Chatham and Thamesville, and the Municipality watches the dikes and pump stations that keep the low ground dry. Lake Erie flooding is a storm problem, with waves over the shore road and erosion taking metres of bank at a time. Sewer backup arrives at the floor drain during or just after heavy rain and smells like sewage; Chatham’s and Wallaceburg’s older streets are most exposed. Groundwater arrives clear at the wall-floor joint on clay that holds water against foundations, and rural basements depend on the municipal drain in the road allowance being clear.

Photograph where the water first appeared and when. A river warning, a storm and a smell, or a wet spring and clear water each point to a different fix.

Municipal drains: the rural answer

Outside the towns, Chatham-Kent’s farmland and rural lots drain through a network of municipal drains, open ditches and tile, established under Ontario’s Drainage Act and maintained by the Municipality with costs shared among the properties they serve. If your rural basement floods because the ditch in front of the house is full and not draining, the first call is the Municipality’s drainage superintendent, not a plumber. Private tile on your own land is yours to keep clear, and it connects to the municipal drain.

The pump stations and dikes along the Thames and the lake are the Municipality’s and the conservation authority’s; they have been reviewing them since 2018.

What the fixes do, and what has been offered

A backwater valve is a one-way flap on the sanitary lateral that closes when the sewer surcharges so sewage cannot flow back into the house; while it is closed nothing in the house drains. A sump pump with a pit collects groundwater from the foundation drain and pumps it outside, with a battery backup for the outages that come with the storms. Neither stops the Thames or the lake. The Municipality has offered programs for backwater valves and related protective plumbing at times; check the current page before signing a quote. In the towns, the Municipality owns the sanitary and storm sewers beyond your property line and the lateral on your property is yours; a camera inspection with a locate tells you which side a fault is on.

• LTVCA flood-plain map checked for your address
• Municipality’s current program checked for eligibility
• Licensed plumber and Municipality plumbing permit number
• Rural: municipal drain condition and the drainage superintendent’s number
• Sump pump tested, backup and alarm

Insurance and the shoreline

Sewer backup and overland water are usually separate add-ons on an Ontario home policy, and after 2018 overland coverage along the Thames and the lake became harder to get; ask your broker what is available at your address. Shoreline protection on Lake Erie needs permits from the conservation authority and the province, and a contractor who builds it without them can leave you with a demolition order. Erie Shore Drive has been under evacuation orders in storms; know the Municipality’s alerts.