What is a Rainway?

    A multi-block series of green rainwater infrastructure designed to acknowledge a historic stream. The green rainwater infrastructure collects and cleans rainwater from surrounding areas such as streets, sidewalks, and laneways to honour the lost stream.

    What is rainwater management?

    The infrastructure systems in place that manage rainwater, which can include catch basins, pipes, ditches, and green rainwater infrastructure.  

    What is Green Rainwater Infrastructure?

    Green rainwater infrastructure (GRI) is an approach to rainwater management that uses a combination of engineered and nature-based solutions to protect, restore, and mimic the natural water cycle. Rainwater running off of hard, impermeable surfaces such as roads, sidewalks, and rooftops is captured, stored, and filtered.  The water then rejoins the water cycled by absorbing into the ground, returning to waterways and/or the surrounding atmosphere.  

    GRI is both a drainage infrastructure tool as well as a method to manage and enhance urban water and natural systems.  When integrated with grey infrastructure (traditional sewage and pipe systems), GRI can provide environmental, social, and economic benefits.   

    a drawing of the natural and urban watercycle

    What are examples of green rainwater infrastructure?

    There are many types of green rainwater infrastructure.  Some of the common ones seen in Vancouver include rain gardens, rainwater tree trenches, and permeable pavement.  

    Rain gardens (also called bioswales or bioretention) are shallow depression that features layers of rocks, engineered soils, and vegetation such as trees, shrubs, and flowers. They help to capture and clean rainwater.  

    Drawing of a rain garden

    Rainwater Tree Trenches are a type of green rainwater infrastructure that uses trees for rainwater management.  Structures underground provides extra room for tree roots to grow while also storing rainwater that can be used by trees.  

    Drawing of a rainwater tree trenchPermeable Pavement is a special type of surface used on road, sidewalks, driveways, and parking lots that allows rainwater to pass through the pavement and soak into the ground.  

    Drawing of alternative pavement

    How does rainwater become polluted?

    The rainwater that falls on our hard urban surfaces – also known as urban rainwater runoff - collects pollutants found on our rooftops, streets, parking lots, and other hard surfaces. These pollutants are then conveyed with the water through the sewer system to our treatment plants, or directly into local waterbodies.

    Pollutants commonly found in rainwater include: 

    • Hydrocarbons and petroleum pollutants
    • Bacteria and viruses
    • Heavy metals
    • Litter
    • Nitrogen and phosphorous
    • Micro-plastics
    • Sediment
    • Salt

    Green rainwater infrastructure captures and help clean rainwater before the water infiltrates into underground aquifers or is conveyed through the sewers to surrounding watersheds. A number of studies both in the laboratory and field have proven that GRI is able to capture and help treat rainwater pollutants with the exception of salt.  

    Will you be daylighting St George Creek?

    Daylighting is a process in which part of a creek which has been buried underground in a pipe gets exposed to the surface.  

    Daylighting te Statlew or St George Creek is not being considered for this project because of how deep the creek has been buried below ground.  However, there are opportunities to acknowledge the importance and location of the creek through the creation of a unique rainway corridor.