Rainwater Management

Capitalizing on the enthusiasm and early momentum generated by the Okotoks Conference in September 2004, a number of Alberta agencies have come together to form the Alberta Low Impact Develpoment Partnership. The initiative is co-chaired by the cities of Calgary and Edmonton.

The Department of Fisheries and Oceans is one of three federal agencies that is a Water Balance Model partner. Use of this web-based decision support and scenario modeling tool will enable development project proponents to show how they can achieve stream protection objectives.

“There is a need for a new approach to hydrologic design. A key message is that a rainfall-based approach does not work effectively. This is why I advocate a runoff-based approach. Duration of discharge is important because it links directly to stream health”, stated Jim Dumont.

The ISMP Template provides a standardized process that includes all of the key components for rainwater and stormwater management. These are categorized in terms of three disciplines – engineering, planning and environmental. “A municipality can decide which components are applicable, and can establish the level of effort required based on risk and local conditions. Not all of the components may be relevant for a given watershed or drainage catchment,” states Robert Hicks.

In undertaking the Fergus Creek Integrated Stormwater Management Plan, the City of Surrey is pushing the envelope in pioneering the application of innovative approaches that it believes will achieve noticeable benefits over a 50-year planning horizon. The Fergus ISMP “goes beyond the Guidebook” because it is built around a science-based methodology that correlates runoff volume with stream health, reported Paul Ham.

“Water-sensitive Urban Design” (WSUD) is a term used in Australia to describe sustainable water cycle management in the urban landscape. To assist practitioners in designing rainwater source control measures, A Handbook for Australian Practice was published in 2005. The Handbook is a compilation of proven approaches that are aimed at solving everyday problems of small-scale rainwater management.

Organized by Cate Soroczan, the event was an information exchange amongst agencies from across the country. It was also precedent-setting in terms of laying the groundwork for future inter-provincial collaboration. Twenty-plus representatives from seven provinces participated, namely: British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec and Nova Scotia.

The practice of low impact development often involves efforts to reduce the impacts of rainmwater runoff using various types of “source controls” designed to minimize runoff volumes. To answer questions about the effectiveness of source controls under a range of land use and climate conditions, an Inter-Governmental Partnership was formed in 2002 to fund development of the Water Balance Model for British Columbia.

The British Columbia-based Inter-Governmental Partnership (IGP) has taken another step towards making the Water Balance Model (WBM) available and relevant to communities across Canada. Initial contact with the Centre for Water Resource Studies at Dalhousie University could open the door to a broader conversation with Nova Scotia stakeholders who see the value in sharing tools and resources through an inter-provincial partnership.

The early success of the Water Balance Model in British Columbia, particularly in promoting an understanding of how to improve the built environment and protect the natural environment, generated interest in expanding the focus of the tool to reach a national audience.