Greater Vancouver Region Develops Design Guidelines for Rain Gardens


Goal is to reduce rainwater runoff volume by capturing rain where it falls

Rain garden

To complement the Water Balance Model for Brtish Columbia, the Stormwater Inter-Agency Group (SILG) – a technical committee of the Greater Vancouver Regional District (GVRD) – commissioned a research project to create Stormwater Source Control Design Guidelines 2005 – Final Report. This work is based on the adaptation of design standards from areas of Europe, Australia, New Zealand and North America with similar climatic and soil conditions. For the complete story, please click here.

“The objective of this project was to reduce information barriers that previously stood in the way of effective implementation of rainwater source controls in the Georgia Basin region of British Columbia. Our focus was on the technical details of practices in landscape areas that treat rainwater through plant materials and soils by infiltration, retention, detention and evapotranspiration', according to Ed von Euw, Senior Engineer with GVRD Regional Utility Planning. 


Rain Gardens

In British Columbia, the technical language is being simplified so that there will be a clearer public and practitioner understanding of the suite of source control options for capturing rain where it falls. Six simplified categories have been defined, of which one is Rain Gardens. Key points to note with respect to Rain Gardens  include:

  • The Infiltration Rain Garden is a form of bioretention facility, designed to have the aesthetic appeal of a rain garden, as opposed to a purely functional appearance.
  • Rain Gardens are a concave landscape area where runoff from roofs or paving is allowed to pond temporarily while infiltrating into deeply constructed soils below.
  • The surface planting of Rain Gardens is dominated by trees, shrubs, and groundcovers, with planting designs respecting the various soil moisture conditions in the garden.

Key features of the research information have been displayed in a set of poster presentations. To download the poster for Rain Gardens, please click here.

The combination of the Water Balance Model and the Design Guidelines enable engineers, planners, landscape architects, architects, developers and builders to select, assess and implement landscape-based solutions that make sense.


Posted August 2006