Water Balance Model for British Columbia: Land development and watershed protection can be compatible
WATER BALANCE METHODOLOGY:
Founded on British Columbia case study experience, and published by the BC Ministry of Water, Land and Air Protection in 2002, Stormwater Planning: A Guidebook for British Columbia formalized a science-based understanding to set performance targets for reducing rainwater runoff volumes and rates. These targets represent the synthesis of biological and hydrological understanding. At the heart of the Guidebook is the Water Balance Methodology. Recognizing that practitioners and others needed a tool so that they could readily apply the Methodology, the Inter-Governmental Partnership then developed the Water Balance Model for British Columbia.
LAND DEVELOPMENT AND WATERSHED PROTECTION CAN BE COMPATIBLE:
The widespread changes in thinking about rainwater runoff impacts that began in the late 1990s reflected new insights in two areas: hydrology; and aquatic ecology. These new insights were the result of improved understanding of the causes-and-effects of changes in hydrology brought about by urban development, and the consequences for aquatic ecology.
The missing link between Policy Objectives and Site Design Practices had been a Science-Based Understanding of development impacts. The initial breakthrough in filling this knowledge-gap was achieved in Washington State when Rich Horner and Chris May published their landmark findings in 1997 on the relationships between watershed imperviousness and biological impacts. The next breakthrough was in British Columbia with the development of the Water Balance Methodology in 2000. Through a science-based understanding of the relationship between hydrology and aquatic ecology, it is possible to derive a comprehensive set of watershed protection objectives. In turn, the Water Balance Model for British Columbia enables evaluation of the on-the-ground achievability of policy objectives.
BUILDING BLOCK PROCESS:
The genesis of the Water Balance Methodology was UniverCity, the sustainable community being built adjacent to Simon Fraser University atop Burnaby Mountain. Translating high expectations for this “green” development into practical design guidelines meant revisiting accepted drainage engineering practice; this need for innovation eventually led to development of the Water Balance Model for British Columbia.
This aerial, taken by Dark Chamber Photography, shows construction of UniverCity as of August 2005
WATER SUSTAINABILITY ACTION PLAN:
The Water Balance Model for British Columbia is one of six inter-connected elements that comprise the Water Sustainability Action Plan for British Columbia. The Action Plan provides a partnership umbrella for on-the-ground initiatives that are promoting water stewardship across the province, and that are also informing Provincial policy through shared responsibility. The six elements that comprise the Action Plan demonstrate how to integrate water management with community planning and development.
The Inter-Governmental Partnership is collaborating with a number of organizations to advance acceptance and province-wide use of the Water Balance Model for British Columbia.