Implementation of low impact development on commercial and industrial developments in the Nose Creek Watershed

This project demonstrates the potential for stormwater runoff and watershed management benefits from applying Low Impact Development (LID) practices to commercial and light industrial land use planning and development in the climatic conditions characteristic of the Calgary region of Southern Alberta. A generic site with spatial dimensions, site development components and building footprints typical of existing commercial and light industrial developments in the Nose Creek Watershed on the northern urban-rural fringe of the City of Calgary is used for this design demonstration.;The "Water Balance Model" software was developed by a Federal-Provincial Intergovernmental Committee in British Columbia. It was adapted to Calgary's climatic and soil conditions for site application using different development scenarios. The Water Balance approach focuses on managing precipitation runoff volume. The model analyses site development characteristics to identify on-site infiltration, evapotranspiration and runoff volumes and tests various user-defined source controls (green roofs, pervious paving, absorbent landscaping, biorention and infiltration facilities) to evaluate their volume management capacity.;The results of the development scenario testing showed that with conventional site design and development, 73% of precipitation received on the demonstration site becomes runoff into Nose Creek. By contrast, with a combination of five source controls applied in site design, the percentage of received on-site precipitation that becomes runoff is only 9%, and 91% of precipitation received in an average year can be retained and evaporated or infiltrated on-site.;Key informant interviews were conducted to identify current design, approvals, construction and maintenance 'barriers' to LID practice at the municipal level. The key informant results found that the two primary barriers are lack of information and education and the need for specific regulations. Twenty recommendations related to reducing these identified barriers in all four categories (design, approvals, construction, maintenance) are made to encourage greater implementation of LID practices at the site design and project approval level in the Calgary area.;Key words. Low Impact Development, stormwater management, land use planning, Water Balance Model, commercial, industrial.