Source Watershed Assessment

  • Source Watershed Assessment

In 2014, The City of Calgary developed the Drinking Water Safety Plan for its drinking water system and is moving into implementation. Consistent with the “Source to Tap” framework that guides drinking water safety across Canada, Calgary intends to develop a detailed Source Water Protection Plan.

Given the large size of the Bow and Elbow River watersheds upstream of the City’s intakes, and the range of land uses in the watersheds, it was necessary to first complete a Source Water Assessment to separate the “serious and imminent threats” to the water supply from the potentially long list of contaminants that exist. To this end, Associated Engineering was commissioned to undertake a risk assessment framework.

The source watershed assessment component of the project relied heavily on GIS data from numerous sources and in a variety of formats and qualities, with the challenge to make use of different layers to develop an index of vulnerability. Our GIS specialists were able to do the necessary mapping and spatial analyses. This information was used to determine inherent and residual risk, develop integrated risk characterization mapping and visualization, which ultimately informed the development of management and policy recommendations.