Regional Groundwater Model for the Grand River Basin

Client: Ms. Pat Lapcevic, Hydrogeologist, Grand River Conservation Authority, 400 Clyde Road, P.O. Box 729, Cambridge, Ontario, N1R 5W6

Key Personnel: Dirk Kassenaar

Earthfx Incorporated developed a preliminary regional-scale groundwater model for the entire Grand River Conservation Authority area. The objective of the study was to better understand regional groundwater flow in the GRCA and evaluate the interaction between the river and the various aquifer systems in the basin. A key aspect of the study was the integration of multiple smaller-scale models that were completed within the GRCA, including the RMOW River Wells model, the Waterloo Moraine Model, and the Cambridge and Guelph water supply models along with a number of smaller subwatershed-scale models.
Model development was preceded by a data and resource-mapping compilation using VIEWLOG.

This work resulted in a comprehensive geologic database which included all geophysical data for boreholes in Waterloo Region along with a 300-page interactive atlas containing over 200 full-color maps. Aquifer mapping was updated as well.
The MODFLOW model contains two geologic layers and has a 200 x 200 m cell size. The model represents the GRCA’s extensive surface water network, composed of 153 catchments containing 31,000 classified stream and river segments.
Key outcomes from the study included a well-calibrated regional model, a better understanding of groundwater/surface water inter-action, a well database fully integrated with the hydrogeologic model, and a useful management tool for GRCA staff to manage groundwater use.