The City of Winnipeg is located in a former glacial lake with a remarkably low-lying flood plain over a flat topography. The low elevation of the City made sewers and other buried infrastructure particularly vulnerable to damage from flooding. With climate change bringing more frequent and severe intense rainfall events, private homes in Winnipeg became increasing susceptible to damage from sewage backup through basement floor drains, toilets, and sinks. This observation was supported with data from insurance companies, which indicated that damage from sewer backup had been growing for three or four decades, including an alarming increase over the last five to ten years. In recent years, damage to homes from sewer backup and other water damage had exceeded $2 billion annually. These national trends combined with the geography of the region made it paramount for Winnipeg to introduce adaptation. The City experienced many extreme rainfall events in the past that overwhelmed the capacity of its storm and wastewater management systems. These rainfall events convinced local authorities to think aggressively about mitigation measures to protect homes from basement flooding—an issue exacerbated by climate change.
After past rainfall events overwhelmed the capacity of the storm and wastewater management systems in Winnipeg, the City introduced a backwater valve by-law in 1979 followed by several subsequent actions to protect homes from basement flooding. Data from insurance companies indicated that damage to homes from sewer backup was growing for three to four decades, including an alarming increase over the last five to ten years. It is no coincidence that at the same time climate change is contributing to more frequent intense rainfall events, which lead to sewers backing up into people’s homes. Winnipeg took proactive action in the 1970s, and continues to evolve and renew their programs that encourage the use of backwater valves—a valuable protection mechanism against damage from sewer backup. Since 1979, houses have to be built with an in-line backwater valve on the sanitary sewer connection. Approximately 28 percent of houses across Winnipeg have installed a backwater valve and 15 percent have installed a sump pit system since the implementation of the by-laws. Recently, the City made significant commitments to renewal of sewer infrastructure, supported by the new Basement Flood Relief Subsidy Program. This program sought to incentivize homeowners to install backwater valves and sump pit systems by offering a 60% rebate on the purchase of these devices. The cost of the program was shared equally by the City of Winnipeg and the Province of Manitoba. The program generated an additional 1,532 backwater valve and 2,275 sump pit approved applications in three years—a significant increase in the number of protected homes in the City. The success of the subsidy program has prompted the City to apply for three more years of funding from the province.