Investing in Flood Protection and Sea-Level Rise Infrastructure

The City of Richmond, British Columbia, is responsible for local flood protection management including the ongoing operation and maintenance of drainage and diking infrastructure. The City of Richmond is situated 1.0 m above sea level and is protected from ocean storm surge and freshet by a system comprised of 49 km of dikes and 39 drainage pump stations. A major flood in 1948 galvanized funding to build the perimeter dike that exists today. Richmond’s dikes were upgraded in the 1970s and 1980s to accommodate a 200-year flooding event. However, the sea levels along Richmond’s coast are expected to rise 1 m by the year 2100 and 0.2 m of land loss/subsidence is forecasted over the same time period. Proactive adaptation to this climate change threat has been a priority for the City of Richmond. A drainage and diking utility was established in the early 2000s to provide the City with an ongoing source of capital funding to maintain and upgrade Richmond’s flood protection infrastructure.

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.

Identifying Actions

The City has proactively advanced its Flood Protection Program since the early 2000s. A key component of this successful program is continual improvements and advancement of flood protection projects to ensure that the City has a robust diking and drainage system and is prepared to mitigate the adverse effects of inundation. Improved diking and drainage infrastructure, resulting from these projects, provides the City with better protection from sea level rise, freshet, and higher intensity rainfall. The City’s Flood Protection Management Strategy and Dike Master Plans are our guiding framework for continual upgrades and improvements to address climate change induced sea level rise. 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. Funded by the Drainage and Diking utility, grants and development, the City’s flood protection infrastructure is continuously upgraded and improved to address infrastructure age, growth and climate change. Significant progress has been made in upgrading the City’s drainage pump stations to accommodate growth and climate change. Over the last 19 years, since the City introduced a Drainage and Diking utility, the City has rebuilt 11 of its 39 drainage pump stations and has performed significant upgrades on an additional six. This has resulted in significantly increased pumping capacity. In addition, every drainage pump station is designed to have backup power capabilities. The City has successfully partnered with developers to secure dike upgrades through development. In particular, the City actively pursues opportunities to construct super dikes, where land supporting development behind the dike is filled to the same elevation as the dike crest.

Implementation

Richmond’s Flood Protection Program invests in major disaster mitigation to contribute to the Province’s and Canada’s economic growth, citizen safety and building a stronger community. This program includes a Flood Protection Management Strategy, Dike Master Plan, Capital Program, and Drainage and Diking Utility.

The City’s Flood Protection Management Strategy reviews the City’s vision, regional guidelines, and innovation in flood protection to establish a world-class framework for Richmond’s flood protection system. The Dike Master Plan utilizes this framework to develop area-specific solutions for flood protection upgrades based on current climate change science. They are our guiding framework for continual upgrades and improvements to address climate change induced sea level rise.

The Dike Master Plan feeds into the City’s 5-year Capital Plan, which consists of projects targeted to increase citywide resilience to flooding. Capital funding is achieved through a dedicated drainage and diking utility, which currently generates $13.4 million annually. Improved diking and drainage infrastructure provides the City with better protection from sea level rise, freshet, and higher intensity rainfall. In addition to the City’s Drainage and Diking utility, improvements to the City’s flood protection system to address the needs of aging infrastructure and climate change are funded through senior government funding and development. Senior government funding is provided through competitive grant programs, and has supported a wide range of flood prevention and protection researching, monitoring, studies, planning and infrastructure improvements. As a result of proactive flood protection planning efforts, the City has been successful in securing over $30 million in senior government grants that will go towards implementing over $60 million in dike and pump station improvements.

The City has successfully partnered with developers to secure dike upgrades through development. In particular, the City actively pursues opportunities to construct super dikes, where land supporting development behind the dike is filled to the same elevation as the dike crest. The City estimates that up to 20% of dike upgrades along Lulu Island’s perimeter dikes will be completed through development.

Outcomes and Monitoring Progress

Since 1948, the City of Richmond has not experienced any major flooding events. Despite the effectiveness of current infrastructure, Richmond’s General Manager of Engineering and Public Works, John Irving emphasizes the importance of continued investment in flood protection infrastructure. “Existing infrastructure with regards to dikes and pump stations are built to handle existing risk and will likely be good for the next 50 years for sea level rise. After that we’d need to change, taking into account storm surge combined with sea level rise.”

This case study demonstrates the importance of investing in disaster risk reduction. A primary learning outcome of the study is that climate change and seismic risk in Richmond will require extensive further investment. Current investment has resulted in 49 kilometres of dikes, 112 pumps at 39 pump stations, 320 kilometres of ditches and canals, and over 600 kilometres of box culverts and storm sewers. This substantial network of flood protection infrastructure is a measurable outcome of the City’s ongoing investment. Adaptation actions put Richmond in a strong position to respond to even the most unlikely, worst-case climate change scenarios. However, the City is the first to acknowledge that their work in upgrading the community’s resilience to flooding is nowhere near finished.

Next Steps

Several concrete next actions have been identified by the City of Richmond through its updated Flood Protection Management Strategy. To prepare for projected sea level rise over the next century, the City will upgrade the perimeter dike to 4.7 m over the next 25-75 years. The City is also working on mitigating long-term flood risk by actively pursuing opportunities to construct super dikes, where land supporting development behind the dike is filled to the same elevation as the dike crest through new development. The City will continue to proactively seek senior government funding for a wide range of flood prevention and protection research, monitoring, studies, planning, and improvements. Additional action items can be found in the City’s updated Flood Protection Management Strategy. Further, adaptation actions taken by the City of Richmond extend beyond SLR infrastructure; the City is (and has been for many decades) working holistically to build climate resilience within the City’s boundaries. Some of this additional work includes ‘Invasive Species Action Plan’ and the ‘Ecological Network Management Strategy’ – which are both interrelated with climate change and the impacts related to SLR. Additional case studies regarding these two focus areas are forthcoming.

Resources

Link to Full Case Study

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