Author(s): Tamsin Lyle; Vanessa O’Connor; Dave Mclean; Kate Miller
Linked Author(s):
Keywords: Flood; Integrated Management; GIS; Numerical Modelling
Abstract: Flooding is a river system's natural response to occasional large precipitation events. When people decide to use highly productive land on natural floodplains for socioeconomic activities, protection from inundation becomes necessary. A traditional engineering-focused approach to flood control considers physical, technical, economic, and political limitations, but fails to adequately consider social, cultural, ecological and morphological constraints. This requires a better Integrated Flood Management (IFM) approach, that adopts a basin and multidisciplinary approach to flood management to maximise the net benefits from floodplains while reducing the vulnerability and risks due to flooding, promoting community involvement and preserving ecosystems. IFM combines traditional flood management tools with land use planning tools, and integrates environmental and cultural data with modern engineering tools. The heritage designated Cowichan River and Koksilah River on Vancouver Island, British Columbia are recognized as providing highly productive fish habitat, while the lower floodplain contains of the town of Duncan, and significant agricultural land The rivers have undergone anthropogenic alterations over the last century including bridge and dike construction, and channel realignment that have affected channel morphology. In recent years, the valley has experienced many impactful flood events. In 2007, the Cowichan Valley Regional District, in partnership with Cowichan Tribes, the City of Duncan and the District of North Cowichan initiated the development of an IFM Plan for the Lower Cowichan with the goal of reducing the flood risk to all communities, while protecting aquatic and riparian habitat and addressing the cultural values of the rivers. The plan incorporates modern engineering tools and design, including two-dimensional hydraulic modelling, GIS, biological data and the traditional knowledge of the Cowichan First Nation. The plan promotes innovative methods of flood hazard management including flood zoning and development controls in order to minimise short and long-term economic, environmental and social costs and where possible, increase the environmental and social capital of the region.
Year: 2009