A Look Back to Formation of the Inter-Governmental Partnership



Capturing Rain Where It Falls

The practice of low impact development often involves efforts to reduce the impacts of rainwater runoff using various types of “source controls” designed to minimize runoff volumes. The effectiveness of these source controls varies with their design, with precipitation patterns, and with soil type, among other factors. The overall performance of these source controls is obviously of great interest to developers, homeowners and local governments alike.

According to Ted van der Gulik, Chair of the Inter-Governmental Partnership (IGP) that developed the Water Balance Model for British Columbia, “The Provincial Stormwater Planning Guidebook for BC lays out targets for reducing runoff volume to achieve watershed protection objectives. In 2002, the Greater Vancouver Regional District (GVRD) completed a study to evaluate the effectiveness of a suite of such stormwater source controls with these targets in mind.”

“In order to answer questions about their effectiveness, the GVRD's consultant applied a Water Balance Model, an interactive spreadsheet tool that could simulate the performance of impervious controls, absorbent landscaping, infiltration facilities, green roofs and rainwater re-use under various development scenarios”, added Laura Maclean, IGP Co-Chair, “After exploring the capabilities of the model, a group of municipal, provincial and federal government representatives saw the potential to use it to integrate volumebased analysis of rainwater management strategies into land use planning throughout British Columbia.”

The Inter-Governmental Partnership was struck in the summer of 2002 to secure access to the model and develop a more user-friendly version, later called the Water Balance Model for BC. The Inter-Governmental Partnership is chaired by the BC Ministry of Agriculture & Lands, and co-chaired by Environment Canada. A number of municipalities are currently engaged in the project, and others who share an interest are invited to join as the project evolves.

“The inaugural meeting of the Inter-Governmental Partnership was held in November 2002 to establish project objectives with the consulting team”, noted van der Gulik, “The end result was a user-friendly model that is used to inform and evaluate land use planning decisions for their ability to meet rainwater management objectives, both at the scale of the individual development site and the watershed.”

According to Kim Stephens, IGP Project Coordinator, “The founding members of the Inter-Governmental Partnership had the opportunity to participate actively in development of the model and graphic user interface, and were the first to be trained in the use of the resulting Water Balance Model for BC. Future project phases are anticipated to involve field testing and calibration of key model assumptions, and linking the model to regional GIS and precipitation databases.”

For more information about the Water Balance Model for BC or for information about getting involved with the Inter-Governmental Partnership, please contact:

Ted van der Gulik
Resource Management Branch
BC Ministry of Agriculture & Lands
Phone: (604) 556-3112


To Learn More:

For more information about how the IGP is organized, please click on Management Framework for the Inter-Governmental Partnership, August 2003

For more information related to historical context, please click on this link to Re-Inventing Urban Hydrology -Going Back to Basics to Develop New Tools


Posted September 2003