Impacts of Urbanization on Rainwater Flooding

Impacts of Urbanization on Rainwater Flooding

Research from UBC’s Okanagan campus showed municipalities should put a greater emphasis on green initiatives to reduce heavy rainfall flooding urban areas.

Rainwater flooding occurs when an urban drainage system has trouble funnelling intense amounts of rainfall. In Canada, the costs of flooding from extreme rainfall events have been recently estimated at more than $13 billion.

The study reported that urbanization changes a city’s land cover – more buildings, roads and other development means fewer porous areas made up of trees, grass and natural greenspaces. So instead of being absorbed by these natural areas, rainfall ends up in a city’s drainage system.

“By promoting green development like green roof constructions and encouraging the use of porous pavement materials, urban planners can reduce the vulnerability of neighbourhoods currently at risk,” said lead author Yekenalem Abebe, a PhD student in the School of Engineering.

The research goes on to provide a detailed methodology that will assist municipalities in identifying the areas at risk and help identify unknowns in the decision-making process.

“Flood risk mitigation requires a coordinated effort between multiple stakeholders,” explained Abebe. “We are currently collaborating with municipalities in the Okanagan region to develop a holistic approach looking into climate change, infrastructure management and urban planning.”