Green rainwater infrastructure (GRI) tools and co-benefits

Common types of GRI tools, key co-benefits, and examples

Landscape-based GRI

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  Absorbent landscapes

  These landscapes use trees, vegetation, and soil modifications to absorb and hold rainwater without the use of ponding.

  Co-benefits

  • Improves water quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Enhances biodiversity and habitat
  • Reduces sewer infrastructure costs
  • Improves aesthetic appeal

  Examples

  • Large evergreen trees
  • Surface vegetation such as groundcover plants
  • Additional uncompacted (loose) topsoil
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  Bioretention practices

  These practices use shallow basins layered with rocks, soil, and vegetation designed to retain, absorb, and clean large amounts of rainfall through temporary ponding.

  Rainwater is used by plants, filtered of harmful pollutants (as it soaks into the ground), or removed from the site through drainage pipes.

  Co-benefits

  • Improves water quality
  • Improves air quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Enhances biodiversity and habitat
  • Increases access to nature and improves education, health, and well-being
  • Reduces sewer infrastructure costs
  • Improves aesthetic appeal

  Examples

  • Rain gardens (a vegetated ground depression designed to let water soak into the ground)
  • Bioretention cells and planters (a vegetated ground depression. Typically uses a drain and is larger than a rain garden)
  • Bioswales (a vegetated ditch designed to let water soak into the ground)
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  Downspout disconnection 

  A process where rainwater from a roof downspout pipe is redirected away from the sewer system. Instead, it flows into rain barrels, cisterns, or permeable areas where the rainwater can be stored, reused, or allowed to soak into the ground. 

  Any overflow of rainwater may be captured and directed back into the sewer system.

  Co-benefits

  • Improves water quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Conserves potable (drinking) water
  • Reduces sewer infrastructure costs
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  Permeable pavement

  Permeable pavements are surface materials that allow rainwater to flow through and soak into the soil, which filters and cleans the water.

  The rainwater either seeps further into the ground or is removed by an underground drain.

  Co-benefits

  • Improves water quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Reduces sewer infrastructure costs
  • Improves aesthetic appeal

  Examples

  • Permeable concrete pavers (concrete with gaps that allow water to pass through)
  • Porous asphalt and rubber
  • Grass grid pavers or country lane (waffle grids that allow grass to grow in the middle)
  • Permeable epoxied gravel (gravel bound by epoxy resin)
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  Rainwater tree trenches

  Rainwater tree trenches are typically used in highly urbanized areas to store rainwater and support tree growth.

  Rainwater flows into the trenches filled with soil where it is used by trees or seeps into the ground.

  Co-benefits

  • Improves water quality
  • Improves air quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Enhances biodiversity and habitat
  • Conserves potable (drinking) water
  • Increases access to nature and improves education, health, and well-being
  • Provides recreational, play, and amenity space
  • Reduces sewer infrastructure costs
  • Lowers heating and cooling costs for buildings
  • Increases property value
  • Improves aesthetic appeal

  Examples

  • Soil cells (plastic frames filled with soil)
  • Structural soil (large crushed stone and soil)
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  Subsurface infiltration 

  This practice uses conventional grey infrastructure to receive, store and then disperse the rainwater into the ground.

  Co-benefits

  • Improves water quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Reduces sewer infrastructure costs

  Examples

  • Trenches (typically gravel-filled)
  • Dry wells (underground structures that disperse water through a number of small openings) 
  • Soakaways (geotextile-lined pits filled with rubble or stone that allow water to soak into the ground)
  • Chambers (rectangular structures)
  • Arches (curved structures)
  • Modular systems (pre-built units)
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  Large-scale practices

  The various GRI tools and practices designed to handle large amounts of surface water on large private and public properties.

  These tools also aim to mimic or restore the natural processes and co-benefits found in natural wetlands and streams.

  Co-benefits

  • Improves water quality
  • Improves air quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Enhances biodiversity and habitat
  • Increases access to nature and improves education, health, and well-being
  • Provides recreational, play, and amenity space
  • Reduces sewer infrastructure costs
  • Increases property value
  • Improves aesthetic appeal

  Examples

  • Engineered wetlands
  • Floodable spaces
  • Stream daylighting (the process of uncovering buried streams and restoring them to their natural state)

Building-based GRI

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  Green roofs (also known as living roofs or vegetated roofs)

  Green roofs are multifunctional GRI tools designed to manage rainwater and offer additional co-benefits. They use a combination of plants, engineered soil, and various filter fabrics.

  Co-benefits

  • Improves water quality
  • Improves air quality
  • Reduces runoff and flooding
  • Enhances resilience to climate change
  • Enhances biodiversity and habitat
  • Supports urban agriculture
  • Increases access to nature and improves education, health, and well-being
  • Provides recreational, play, and amenity space
  • Reduces sewer infrastructure costs
  • Lowers heating and cooling costs for buildings
  • Increases property value
  • Improves aesthetic appeal

  Examples

  • Green roofs (roofs covered with vegetation and engineered soil)
  • Blue-green roofs (green roofs with a shallow water storage reservoir)

  Learn more about green roofs

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  Non-potable systems

  These systems are designed to collect, store, treat, and distribute non-potable (non-drinkable) water for specific uses in buildings and facilities.

  Common sources of water for these systems may include rainwater and clear water waste. Common uses for water from these systems include toilet flushing and irrigation. 

  Information icon These are examples only. We regulate specific allowable sources and allowable uses. Learn more by reviewing the Vancouver Building By-law

  Co-benefits

  • Enhances resilience to climate change
  • Conserves potable (drinkable) water

  Examples

  • Water harvest, treatment, and re-use