Report 91

Report 91

REP 91

Regional Geological and Hydrogeological Characterization of the Calgary-Lethbridge Corridor in the South Saskatchewan Regional Planning Area

In partnership with Alberta Environment and Parks (AEP), the Alberta Energy Regulator/Alberta Geological Survey (AER/AGS) undertook a study in the Calgary-Lethbridge Corridor (CLC) area of southern Alberta to support the development and implementation of a management approach for groundwater in the region. The objective was to compile existing geological and hydrogeological information for the CLC, and interpret it within a new hydrostratigraphic framework. This characterization aims to be the foundation for defining aquifer units and associated groundwater management units in the CLC, along with informing development of a groundwater monitoring framework.

The report details the methods and results of dividing the shallow subsurface into three Neogene-Quaternary hydrostratigraphic units (HSU), based on the spatial distribution of coarse- and fine-grained sediments, as well as ten Upper Cretaceous- Paleogene HSUs, based lithostratigraphic geological formations, to facilitate mapping of hydraulic properties. Mapped hydraulic properties include potentiometric surface, depth to potentiometric surface, total dissolved solids, and regional confined and unconfined conditions for each HSU. Regional recharge and discharge areas were evaluated including analysis of vertical gradients and numerical modelling of potential recharge. Additionally, the distribution of rock properties within modelled bedrock units was analysed to illustrate the spatial distribution of potentially permeable sandstone-bodies within the larger lithostratigraphic HSUs.

Results of this work contribute to a better understanding of the regional hydrogeology of the CLC, which is required in order to focus future studies relating to land use planning and groundwater monitoring.

Atkinson, L.A., Liggett, J.E., Hartman, G., Nakevska, N., Mei, S., MacCormack, K.E. and Palombi, D. (2017): Regional geological and hydrogeological characterization of the Calgary-Lethbridge Corridor in the South Saskatchewan regional planning area; Alberta Energy Regulator, AER/AGS Report 91, 175 p.