Jasper Candel and Adriaan de Bourgraaf went to Calgary with their ACSN-scholarship for their internship at Deltares, to study the flood that occurred last year. They are locally supervised by the University of Calgary. Jasper and Adriaan wrote a research report for our website, and will keep us updated:
Many homes were destroyed in Calgary due to large flooding last year, in June 2013. Around 60% of the damage was due to groundwater flooding. Tens of thousands people were forced out of their homes because of widespread flooding, as a provincial state of emergency was declared. These types of floods are associated with the snow melt and an intense precipitation peak around June. Solutions are needed to mitigate these floods and understand the groundwater flood processes. Our internship is a hydrogeological exploration of the surface-groundwater interactions of the Bow River catchment, and consists of collaboration between the Dutch research institute Deltares, the University of Calgary and Wageningen University.
We will be working for 3 months at the University of Calgary, from middle of May until middle of August, to study the effects of the groundwater level in the alluvial aquifer on the water level in the river. This problem needs an objective perspective since stakeholder groups are focusing on their interests instead of the facts. Questions that have to be answered are: How fast does the groundwater respond to the water level in the Bow River? How close to the river will houses get flooded by groundwater? What is the relation between the heterogeneity of the alluvial aquifer and the surface water / groundwater interactions?
We also met different stakeholder groups. We had a meeting with the water department of the City of Calgary who is very interested in our results, since they lack knowledge of groundwater flooding. It will help them with the evacuation plans and risk assessment for the next flood. Also it will help them for flood mitigation construction work. Since little knowledge about groundwater flooding exists, most constructions plans are focusing on surface water flooding. Building a dike along the river, for example, might not have any effect because groundwater can still flow below, through preferential groundwater flow paths.
We are working together with Jason Abboud, an undergraduate student in geology at the University of Calgary. Together we installed level-loggers at 7 locations where we monitor the groundwater levels near the river, and will model the groundwater response to the river level. Additionally we want to map the geological heterogeneity of the alluvial aquifer to understand different groundwater responses. Lastly, we will interview the citizens who were affected by the flooding, to derive the reach and effect of the groundwater flood.
This week, the professors from the Geoscience Department are taking us on a raft trip through Calgary to get to know the river better. That’s a nice way of getting to know the area!