Understanding and Assessing Impacts
The City of Richmond, British Columbia, is situated on a coastal floodplain at the mouth of the Fraser River and adjacent to the Pacific Ocean. This location makes the city vulnerable to flooding by storm surge, high tides, rising sea levels, and overflow from the Fraser River from heavy rainfall and snowmelt. By the end of the century, sea levels along Richmond’s coast are expected to rise approximately 1 meter, prompting the need for adaptation action. A significant flood in 1948 was the main motivator for Richmond’s initial flood protection efforts. Since then, the City has continued to invest in flood protection infrastructure in response to future climate change projections. This includes establishing a drainage and diking utility in the early 2000s to provide the City with an ongoing source of capital funding to maintain and upgrade Richmond’s flood protection infrastructure.
The City’s drainage system is designed to accommodate a one in 10-year return period rainfall event. Redundancy and the ability of the drainage system to disperse water quickly is key to Richmond’s flood resilience. The system can handle heavier rain events than the 10-year return event through the redundancy and storage in the box culvert system that runs under Richmond’s major roads. These box culverts interconnected with watercourses end up at one of the 39 drainage pump stations located across the island.
Richmond’s robust diking network is built to withstand a one in 500-year return period flooding event. The City’s Flood Protection Management Strategy is the guiding framework for continual upgrades and improvements to the City’s flood protection system. A key action identified in the City’s Flood Protection Management Strategy involves continuing to upgrade the City’s perimeter dike to 4.7 m in the next 25 to 75 years to stay ahead of climate change induced sea level rise. The City’s Dike Master Plans address this need by recommending dike upgrade options for each dike reach throughout the City. The City’s flood protection infrastructure is continuously upgraded and improved to address infrastructure age, growth and climate change. Richmond understands the long-term risks posed by climate change. As a result, adaptation efforts are being implemented to ensure new developments and city infrastructure can withstand even the worst-case scenarios for several decades to come.