GUIDANCE DOCUMENT: Primer on Rainwater Management in an Urban Watershed Context (November 2011)

Science-Based Understanding

Released in November 2011, the purpose of the Primer on Rainwater Management in an Urban Watershed Context is to provide engineers and non-engineers with a common understanding of how a science-based approach to rainwater management has evolved since the mid-1990s:

  • First, research by Richard Horner and Chris May in Washington State identified limiting factors for stream health, and established an order-of-priority. Their findings provided a road map for integrated rainwater management.
  • Next, the “made in BC” concept of the Rainfall Spectrum led us to look at rainfall differently. This resulted in the Water Balance Methodology and the ability to quantify and assess the hydrologic effectiveness of ‘green’ infrastructure.
  • After that, a fresh look at other early engineering and biophysical research opened a window into the science of stream erosion and how it could be correlated with stream health.
  • The synthesis of the three streams of thinking then provided the technical foundation for ‘designing with nature’ in order to soften the ‘water footprint’ of development. In BC, we have continued to build on this foundation.

Pioneer research yielded guiding principles; these are standing the test of time. Evaluation of, and analyses using, the entire rainfall and stream discharge spectrum allows us to see new connections to stream health and to begin the process of creating effective mitigation strategies,” reports Kim Stephens, Executive Director, Partnership for Water Sustainability in British Columbia.


To download a copy, click on Primer on Rainwater Management in an Urban Watershed Context.