CIties adapt to extreme rainfall Celebrating local leadership By Paul Kovacs, Sophie Guilbault and Dan Sandink December 2014
Local governments are confronting one of the most important issues of our time – the alarming recent increase in damage to homes from extreme rainfall. Communities large and small across Canada are now taking action to reduce the risk of basement flooding and damage to property from sewer backup. This book describes 20 of the many successful local projects underway in communities that are adapting to better address the risks associated with extreme rainfall.
This book recognizes and acknowledges local leadership in addressing the risk of basement flooding. Mini case studies showcase successful local actions that can and should be used by communities across the country to confront the dual challenge of waste and stormwater management. The local policy decisions presented in this report are, in our opinion, scientifically sound, and provide a sustainable foundation for long-term success.
In recent years, severe rainfall has replaced fire to become the leading cause of damage to Canadian homes. Damage to homes from sewer backup and basement flooding now exceeds $2 billion a year, and has been rising at an unsustainable rate for more than 25 years. Moreover, it is inevitable that the frequency and severity of extreme rainfall events will escalate as a result of climate change, threatening to further increase the damage to homes unless we adapt.
Much of the damage to homes is preventable if local governments and homeowners apply existing knowledge to the design and maintenance of buildings and infrastructure. Fortunately, local governments, property owners and other stakeholders are starting to take action. Over the next few decades, it is expected that Canadians will experience more frequent and intense rainstorms. Nevertheless, if we adapt, it is possible that we could also experience reduced stormwater damage to homes.
In this report, we document some of the ways local governments seek to influence private behaviour. For example, Ottawa regulates the construction of new homes to ensure that builders install backwater valves. Kitchener and Waterloo have stormwater fees based on usage. London provides incentives for at-risk homeowners to disconnect weeping tiles. Halifax provides public information about the options available to interested stakeholders.
Finally, we observe that the trigger for action by most governments across Canada involved responding to damage from an extreme rainfall event. Nevertheless some communities have been proactive, seeking to take early action before large losses strike. For example, Collingwood has mandated the installation of backwater valves in new homes and Surrey requires the replacement of storm laterals when substantial renovations are planned.
Considerable effort is required to regain control over the risk of damage to homes from extreme rainfall, nevertheless the direction we must follow is becoming clear. All stakeholders are encouraged to share these and other stories of successful efforts by local governments, celebrating the actions of progressive communities that have begun to show the way forward.