Combined Sewer Overflow Locations in Niagara

Niagara Region has signs posted at publicly accessible sites close to overflow locations that warn about potential hazards and precautions on water use following wet weather. These precautions are not in place at all times but are recommended after wet weather when overflows may affect water quality and safety.

There are combined sewer overflows located in both Regional and municipal infrastructure throughout Niagara.

Overflows allow excess water to exit the sewer systems when pipes can not handle the increased flows due to wet weather and melting snow. Overflows prevent sewage from backing up into basements.

Reporting frequency

Niagara Region updates the data on recent overflows four times a year. The data presented below contains records from May 01, 2023 to April 30, 2024.

Residents seeking information on a specific overflow outside of the normal reporting period can contact the water and wastewater division.

Historical data on combined sewage overflows

Overflows by municipality

The overflow information displayed pertains to overflows occurring at facilities owned and operated by Niagara Region. For specific information on local municipal overflows, the user should contact their local municipality.

Choose a city or town from the following list to see information about recent combined sewer overflows:

• Fort Erie
• Grimsby
• Lincoln
• Niagara-on-the-Lake
• Niagara Falls
• Pelham
• Port Colborne
• St. Catharines
• Thorold
• Welland
• West Lincoln

Niagara Region has no sewers in Wainfleet.

Overflow volume

During wet weather, the sewage normally present in the sewer is highly diluted by the incoming storm water. The volume discharged may appear large, but the actual amount of sewage present in the discharge in relation to the amount of storm water is much lower.