Combining spatial innovation and Blue Green Infrastructure to build climate resilience in Vancouver

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At a glance

Faced with aging infrastructure, ecosystem pressures and intensifying climate risks, the City of Vancouver recognized the importance of adopting a new approach to sewer system upgrades. GHD helped deliver an innovative solution by combining Infrastructure Development Geospatial Options (InDeGO) with Blue Green Infrastructure, supporting sustainable growth, resilience and water quality improvements.

Faced with aging infrastructure, ecosystem pressures and intensifying climate risks, the City of Vancouver recognized the importance of adopting a new approach to sewer system upgrades.

The challenge

Climate projections indicate a 12% increase in annual rainfall, a 20% rise in extreme rainfall events and sea level rise of up to one metre by 2100 (according to this article in Water Canada Magazine). These changes pose significant risks to service reliability and increase the likelihood of combined sewer overflows, threatening both urban liveability and environmental sustainability. 
 
Within a 985-hectare sewershed, the City set out to separate combined trunk sewers. This effort required solutions that could navigate the challenges of a densely developed urban landscape, complex land use patterns and the need to safeguard ecosystems and community spaces.  

Our response

GHD partnered with the City on the Willow Trunk Feasibility Study to deliver a data-driven planning solution grounded in two key components: Infrastructure Development Geospatial Options (InDeGO) and Blue Green Infrastructure (Nature-based Solutions approach). 

InDeGO is a multi-criteria analysis tool that supports complex infrastructure planning by integrating spatial data with structured decision-making frameworks. Used in Australia for more than 15 years, it enables planners to assess options based on a range of criteria. For the Willow Trunk project, InDeGo helped GHD optimize sewer alignments by analyzing factors such as land use, park proximity, infiltration potential, flood risks and other urban constraints - critical considerations in a densely built-up area anticipating future growth. 

Blue Green Infrastructure principles complemented this planning approach. GHD’s team identified opportunities to incorporate green rainwater infrastructure and create new urban wetlands, helping to manage stormwater naturally, support biodiversity and enhance the liveability of densely populated areas. 

While many municipalities have internal GIS capabilities, clients engage GHD for our integrated perspective. We combine geospatial analysis, water management expertise and sustainable design thinking to deliver more holistic and resilient outcomes. 

This project also reflects GHD’s Future of Water approach, which drives investment in emerging ideas, technologies and approaches that advance sustainable water solutions across the globe. 

The impact

Through the Willow Trunk Feasibility Study, GHD provided the City of Vancouver with a prioritized path for achieving its goals. The project outcomes include: 

  • Optimized sewer separation plans that balance technical, environmental and social considerations 
  • Increased growth capacity in an already developed urban area 
  • Reduced flood risk and stormwater impacts through sustainable infrastructure 
  • Enhanced water quality and support for local biodiversity 
  • A stronger foundation for adapting to future climate conditions, including sea level rise and extreme rainfall

By combining leading-edge spatial decision tools with Blue Green Infrastructure, GHD helped Vancouver advance its vision for a more resilient, sustainable city.