State of Subsurface Knowledge to Support Aquifer Mapping Across the Alberta–Northwest Territories Border

This review summarizes the state of subsurface information and knowledge to support aquifer mapping across the Alberta–Northwest Territories (AB–NWT) border, which will address some of the elements identified in the Groundwater Learning Plan of the Bilateral Water Management Agreement between the Government of the Northwest Territories and the Government of Alberta. The state of subsurface knowledge to support aquifer mapping across the AB–NWT border is variable, but can be clearly divided into three geographic zones based on the density of available data.

In the Kakisa–Cameron Hills area, the bedrock deposits are not expected to contain aquifers. The greatest potential for aquifers will be within the sediments that have infilled bedrock valley systems; however, at the AB–NWT border a difference in the interpretation of sediment thickness exists that will require further investigation. Using different data sources in Alberta compared to the Northwest Territories likely causes the different interpretations of sediment thickness. For the Kakisa–Cameron Hills area, the priority for future research is to re-evaluate the major buried valley previously identified, refine the bedrock topographic surface, and investigate the feasibility of a ground-based geophysical survey (e.g., electrical and shallow seismic methods) to confirm the depth and shape of bedrock valleys.

In the Hay River corridor, there is about 5 to 10 m of sediment overlying bedrock that may contain localized aquifers, and potential aquifers within the Upper Devonian bedrock formations. For the Hay River corridor, the priority for future research is to analyze the borehole data (geophysical, water well) and determine if hydrostratigraphic units can be mapped. A synoptic sampling project along the Hay River for naturally-occurring isotopic tracers could also be considered to gain insight to the hydrogeology in conjunction with research related to surface water quality and aquatic ecosystems.

For the Wood Buffalo area, there is very little subsurface information and only a conceptual model developed recently at the University of Alberta offers some insight to transboundary groundwater in the Upper Devonian bedrock formations.