Early Adaptation of Backwater Valve By-laws and Incentives

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.

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Understanding and Assessing Impacts

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.

Identifying Actions

Backwater valves were identified as an effective measure to reduce the risk of sewers backing up into homes during extreme rainfall events. A wide consensus among local government experts across Canada supports the notion that backwater valves are a valuable protection mechanism for all homes connected to a sanitary sewer system. Winnipeg’s plan to encourage the installation of backwater valves began in the 1970s with a focus on by-laws and code enforcement, and has evolved considerably since then. One of the largest obstacles to adaptation in Winnipeg was engaging the population, as most homeowners are not aware of whether or not they have a backwater valve or sump pump, where it is located, and how it needs to be maintained. As a result, the City of Winnipeg recognized the importance of educating the public on how to find and maintain a sump pump and backwater valve. Since the introduction of the initial back valve by-law in 1979, the City made it a priority to combine multi-year subsidy programs with multi-year education initiatives in this space. This maximized the effectiveness of various incentive programs by informing the public on the importance of backwater valve installation, motivating private citizens to capitalize on subsidy programs and install these devices in their homes. By agreeing to help with funding, the Province of Manitoba played an important role in allowing Winnipeg to explore subsidy programs in their adaptation planning, which eventually led to the development of the Basement Flood Relief Subsidy Program.

Implementation

In 1979, Winnipeg became one of the first municipalities in Canada to create a by-law requiring the installation of backwater valves in all new homes. Since 1979, houses have to be built with an in-line backwater valve on the sanitary sewer connection. This by-law was implemented to ensure new development in the City would be resilient to sewage backup during increasingly severe and frequent rainfall events. Not only would this protect private property owners, but it benefits the entire community by limiting sources of inflow and infiltration in the municipal sewer system. Since the core area of Winnipeg was built prior to 1979, the City recently implemented the Basement Flood Relief and Subsidy Program to encourage the installation of backwater valves and sump pumps in older homes outside the scope of the by-law. Winnipeg offered to pay 60 percent of the invoiced costs for the installation of an in-line backwater valve or sump pit drainage system up to a maximum of $1000 and $2000 respectively. The Province of Manitoba agreed to equally share the cost of funding the program with the City of Winnipeg. All homes in Winnipeg qualified for the program regardless of flood history. Since the early implementation of the by-law, Winnipeg also made significant commitments to the renewal of sewage infrastructure throughout the city—now supported by the Basement Flood Relief and Subsidy Program. The City of Winnipeg complemented the mentioned adaptation measures with educational initiatives to inform the public on this issue. The City engaged the public through homeowner presentations through a local Home and Garden Show where they explained how to properly find and maintain a sump pump and backwater valve. They also sent flyers to homeowners on a regular basis with information on backwater valves. Winnipeg’s implemented adaptation measures are constantly evolving and complement each other nicely.

Outcomes and Monitoring Progress

Since implementing the by-law requiring mandatory backwater valve installation in new homes in 1979, about 28 percent of houses across Winnipeg have installed a backwater valve. 15 percent of homes have installed a sump pit system. These figures are tangible proof that Winnipeg has improved its resiliency to future extreme rainfall events that put pressure on the municipal sewer system. Early implementation of backwater valve by-law has protected a relatively large part of Winnipeg against basement flooding. In particular, the by-law ensured the risk of basement flooding in new developments has been low for more than 40 years. The number of protected homes has continued to grow over time, especially with the introduction of the Basement Flood Relief Subsidy Program. In the span of three years, the program generated an additional 1,532 backwater valve and 2,275 sump pit approved applications. This represented a significant increase in the number of protected homes in the City. Fundamental to the success of the subsidy program was the cost-sharing support from the provincial government. Charles Boulet, Senior Project Engineer for the City of Winnipeg, mentioned, “We received a commitment from them (The Province of Manitoba) for the last three years and we are going to ask for three more” Securing the fifty percent cost-sharing was one of the biggest challenges in implementing the subsidy program. Mr. Boulet added that he would completely support the implementation of similar programs in other cities since it represents an effective means to prevent basement flooding. Another important learning outcome from the project was the importance of engaging the public to raise awareness for this issue. Subsidy programs are made that much stronger when the public understands the importance and benefits of what they are purchasing.

Next Steps

Since they took initial action in the 1970s, Winnipeg has continued to evolve and renew their programs to prevent damage to homes from basement flooding. This trend is likely to continue, as the City has demonstrated through its actions that it is committed to improving their adaptive capacity in this area. Mr. Boulet mentioned that one of the next steps for Winnipeg is to renew the cost-sharing agreement with the Province of Manitoba to extend the Basement Flood Relief Subsidy Program for at least three more years. Other next actions for the City include continuing to inform the public on the importance of backwater valve and sump pump installation through existing and new outreach initiatives. The City of Winnipeg will continue to monitor the success of their adaptive measures using data on damages from basement flooding in the city. Winnipeg has done well to continuously evolve and improve their adaptation efforts, resulting in a more safe, resilient community.

Resources

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