Rainfall is posing a dangerous threat to high-precipitation cities such as Vancouver. In natural, forested conditions, 10-20 mm of the rainfall that occurs is intercepted by the lush, vegetative canopy of trees and plants, as it is eventually soaked into the ground before stormwater runoff is generated. This contrasts heavily with unnatural, urbanized areas, where runoff can be generated from as little as 2 mm of precipitation! In an average month in Vancouver, 240 mm of precipitation may fall in 30 days. This equates to an average of 8 mm of precipitation a day. As our climate continues to warm, the frequency and the intensity of our rainfall will only increase. By the year 2050, Vancouver is expected to experience a 5% increase in the volume of rain that occurs over the winter months, alternatively experiencing a 19% decrease in the amount of rainfall throughout the summer months. On Vancouver’s wettest days, extreme rainfall events are expected to intensify by 63%. Our snowpack is expected to decrease by 53%, as our city’s snow will melt due to the increased temperatures. This will result in surface water flooding, sewer backups, and sewage overflow. Currently, Vancouver’s only approach to solving this issue is spending money to fix and replace the damages that are generated from this unmitigated stormwater runoff. The city of Vancouver has allocated $29.5 million towards Sewer Main replacement. The amount of runoff that is generated from our urbanized city is not only harming the environment, but the economy as well. What could possibly be a better solution than spending money to fix all of these damages runoff is creating? Green Infrastructure! By implementing green infrastructure, this issue is combated in a holistic manner. Through thoughtfully designed living roofs, swales, rain gardens, permeable paving, and rain barrels, we are able to mitigate this stormwater runoff in an effective way that supports our environment, economy, and our society.
As you can see through our model, implementing Green Infrastructure offers a solution to the issue of unmitigated storm water in Vancouver. This Green Infrastructure is engineered by landscape architects and hydrological engineers, and is able to adapt to a system specific to our regional conditions to ensure that the water runoff mimics the natural landscape of the land before our urban infrastructure ruined it. In our model under “Economic Trends,” there is an initial delay and drop in property value, which is due to a period of trial and error during the installation of Green Infrastructure. Investment in Green Infrastructure will increase, leading to the rise of property values. Moreover, in the “Environmental” section of our model, we initially see a decrease in our volume of unpolluted, drinkable groundwater. This occurs during the transition phase as Green Infrastructure is becoming implemented into our buildings and landscapes. Eventually, the amount of drinkable groundwater stabilizes and balances off. Furthermore, in our model under “Trends for Green Homes effect on UHI and Snowmelt/Snowpacks,” it is evident that as more homes are built with Green Infrastructure, the Urban Heated Island effect decreases, as the airflow is better regulated, leading to a cooler average temperature throughout the area. This allows for maintenance of our mountainous snowpacks, and thus decreasing the amount of runoff that is generated from snowmelt. Finally, our society is impacted by this solution of Green Infrastructure, as our population will be happy with the ample amount of accessible, clean drinking water that this solution provides them. Morale will increase as homes are no longer at risk of water damage due to flash floods, and environmental awareness will rise, along with motivation and drive towards creating a more sustainable and holistic lifestyle.
