Sustainable Rainwater Management: What Does It Look Like in British Columbia?


Linking the Site to the Watershed and Stream

The web-based Water Balance Model for British Columbia (WBM) quantifies the effectiveness of green infrastructure. This scenario comparison tool can help communities create a future watershed vision by informing their decisions about the impacts, or not, of their ‘water footprint’ on stream health.

Launched by an inter-governmental partnership in 2003, the WBM has been rebuilt on a new platform. It is quicker and easier to use; and it now has launch buttons at three scales of investigation: SITE, NEIGHBOURHOOD and WATERSHED.

WBM workshop hosted by obwb - classroom setting


Knowledge-Transfer Program

In conjunction with the rebuild, the WBM Partnership is implementing an outreach, education and training program to advance Sustainable Rainwater Management. In March, the Okanagan Basin Water Board hosted the first training workshop in the 2012-2013 Series. The workshop was part of the Board’s Climate Adaptation Workshop program.

The instructors for the workshop were Kim Stephens, Executive DIrector of the Partnership for Water Sustainability in BC; and Jim Dumont, Engineering Applications Authority for the Water Balance Model Partnership. These experienced engineers looked at rainfall differently.This led them to pioneer practical applications of water balance thinking. In conducting the training session, they shared stories that provided historical context for development of the Water Balance Methodology. People learn through stories, and storytelling is a foundation piece for the knowledge-transfer program.

Kim stephens (120p) - 2012“The water balance methodology links rainfall to flows in the stream, and hence, protection of stream health. In conducting training workshops, an educational outcome is that municipal engineers, planners and consultants will understand why and how to apply the water balance methodology to achieve targets,” stated Kim Stephens.

Jim dumont (240p) at obwb workshop“The methodology integrates the components of the water balance, and assesses how they change as the percentage of hard surface increases: runoff goes up; infiltration and surface evaporation both go down. Evaporation is critical and typically gets overlooked in conventional drainage modelling,” emphasized Jim Dumont.

“What most people overlook is that evaporation is almost equal to infiltration. This means there is increasingly more volume to manage as the landscape is built over.” (To download a copy of the image that Jim Dumont is pointing at, click here and also see below.)




Workshop Structure

After Kim Stephens introduced core concepts and tested the knowledge of the class, Jim Dumont guided participants step-by-step through a case study application of the Water Balance Model at the SITE scale. He demonstrated how to do scenario comparisons.

“In terms of educational dollars per unit of knowledge, I found the Water Balance Model workshop to be astounding value,” reports workshop participant Michelle Sorensen; a professional engineer with CTQ Consultants Ltd, a consulting firm based in Kelowna, British Columbia.

“I can see how the graphical results would allow me to communicate relevant information to my public and private-sector clients about the effectiveness of rainwater capture and runoff control options – not with complicated tables and calculations, but with relevant, easy-to-understand visual comparisons of the incremental benefits and costs.  What a great tool!”



To read an earlier story about the workshop, click on  Okanagan Basin Water Board hosts first in 2012–2013 Series of “Water Balance Model Training Workshops

To download a copy of the Workshop Handout that guided this interactive knowledge-transfer session, click on Sustainable Rainwater Management in British Columbia: What Does It Look Like?


Posted March 2012