Top Ten Design Considerations for Rain Gardens

Rain gardens are critical infrastructure for sustainable stormwater and rainwater management in developed and developing areas. Rain gardens filter pollutants from runoff and effectively disconnect impervious surface runoff from the storm sewers network for frequently occurring rainfall events. They have been constructed throughout North America and the world to mitigate some of the impacts of land development and to protect downstream watercourses and habitat. However, improper design and implementation of rain gardens has resulted in many gardens not reaching their full potential or failing all together. Failed examples have a greater impact on public acceptance than the successful ones thereby resulting in setbacks in widespread implementation. Therefore it is important to share experiences of which designs work and what needs improvement. This paper provides insights on rain garden design and implementation based on the accumulated experience in the Metro Vancouver region of British Columbia (BC) over the past decade.