Six Conservation Authorities FEFLOW Groundwater Modeling Project

The Six Conservation Authorities (Six CA’s) study developed a strategic plan to understand the regional scale geology and hydrogeology within the Six CA’s watershed area and how they link to the natural environment. To enhance their understanding a conceptual geological model and a numerical groundwater flow model of the entire Six CA watersheds were developed. The groundwater model will be used as a groundwater management tool to:

• Examine the impacts of various changes to the natural system on regional groundwater flow;
• Assess the role of large-scale regional features on regional groundwater flow;
• Determine groundwater flow rates to evaluate groundwater budgeting; and,
• Identify pathways and linkages between both local and regional recharge and discharge areas.

Waterloo Hydrogeologic, Inc., A Schlumberger Company (WHI) was retained by the Upper Thames River Conservation Authority (UTRCA) to develop a three-dimensional conceptual geological model and a three dimensional hydrogeological (groundwater flow) model that  encompass the entire Six CA’s watershed.

This report presents the analyses and development of the numerical groundwater flow model. The model represents the full three-dimensional regional groundwater flow system and extends deep into the underlying bedrock to incorporate interaction with the deeper groundwater system. Through this approach, the Six CA’s can use the numerical model to evaluate the interaction of groundwater and surface water (water balance) and assess the potential influence of additional stresses (e.g. land use changes, pumping etc.). In addition, this model can be updated as new information becomes available and refined as necessary to focus calibration and prediction capabilities in local areas of concern.

 Six Conservation Authorities FEFLOW Groundwater Modeling Project

• Final Report

Appendix A – Groundwater Model Report Figures

• Figure 1-1: Six CA’s watershed study area
• Figure 1-2: Observation well locations
• Figure 1-3: High quality Oil & Gas well locations
• Figure 1-4: Regional cross-section locations
• Figure 1-5: Regional cross-section A-A
• Figure 1-6: Regional cross-section B-B
• Figure 1-7: Regional cross-section C-C
• Figure 1-8: Regional cross-section D-D
• Figure 1-9: Regional cross-section E-E
• Figure 1-10: Regional cross-section F-F
• Figure 1-11: Regional cross-section G-G
• Figure 1-12: Regional cross-section H-H
• Figure 1-13: Regional cross-section I-I
• Figure 1-14: Regional cross-section J-J
• Figure 1-15: Regional cross-section K-K
• Figure 1-16: Regional cross-section L-L
• Figure 2-1: Conceptual hydrostratigraphic structure
• Figure 2-2: Ground surface topography (DEM)
• Figure 2-3: Surficial geology
• Figure 2-4: Bedrock geology
• Figure 2-5: Interpolated bedrock topography
• Figure 2-6: Overburden thickness map
• Figure 2-7: Observed shallow equipotentials
• Figure 2-8: Observed bedrock equipotentials
• Figure 2-9: Subwatersheds and major river systems
• Figure 2-10: Estimated zones of potential recharge and discharge areas
• Figure 4-1: FEFLOW finite element mesh
• Figure 4-2: Hydraulic conductivity distribution – Model Layer 1
• Figure 4-3: Hydraulic conductivity distribution – Model Layer 2
• Figure 4-4: Hydraulic conductivity distribution – Model Layer 3
• Figure 4-5: Hydraulic conductivity distribution – Model Layer 4
• Figure 4-6: Hydraulic conductivity distribution – Model Layer 5
• Figure 4-7: Hydraulic conductivity distribution – Model Layer 6
• Figure 4-8: Hydraulic conductivity distribution – Model Layer 7
• Figure 4-9: Hydraulic conductivity distribution – Model Layer 8
• Figure 4-10: Hydraulic conductivity distribution – Model Layer 9
• Figure 4-11: Hydraulic conductivity distribution – Model Layer 10
• Figure 4-12: Hydraulic conductivity distribution – Model Layer 11
• Figure 4-13: Hydraulic conductivity distribution – Model Layer 12
• Figure 4-14: Hydraulic conductivity distribution – Model Layer 13
• Figure 4-15: Hydraulic conductivity distribution – Model Layer 14
• Figure 4-16: Model boundaries – Model Layer 1 & 2
• Figure 4-17: Recharge distribution – Model Layer 1
• Figure 5-1: Calibration versus Observed Head Values
• Figure 5-2: Modeled overburden groundwater levels
• Figure 5-3: Modeled bedrock potentiometric surface
• Figure 5-4: Six CA Model Baseflow Calibration – Six CA Water Gauge Stations A
• Figure 5-5: Six CA Model Baseflow Calibration – Six CA Water Gauge Stations B
• Figure 5-6: Six CA Model Baseflow Calibration – Six CA Water Gauge Stations C
• Figure 5-7: Regional Water Balance Six CA’s Watershed Model
• Figure 5-8: Forward particle tracks in the overburden and bedrock model layers

Appendix B

• Conceptual Model Report

Appendix C – Conceptual Model Report Figures

• Figure 1: Study Area
• Figure 2: Well Locations
• Figure 3: Cross-Section Locations Maitland Valley CA
• Figure 4: Cross-Section Locations Ausable Bayfield CA
• Figure 5: Cross-Section Locations Upper Thames River CA
• Figure 6: Cross-Section Locations Lower Thames Valley CA
• Figure 7: Cross-Section Locations St. Clair Region CA
• Figure 8: Cross-Section Locations Essex Region CA
• Figure 9: Example Cross Section A
• Figure 10: Example Cross Section B
• Figure 11: Ground Surface Topography
• Figure 12: Conceptual Hydrostratigraphic Structure
• Figure 13: Bedrock Geology
• Figure 14: Bedrock Topography
• Figure 15: Overburden Thickness
• Figure 16: Surficial Geology
• Figure 17: Deep Equipotential Heads
• Figure 18: Isopach Aquifer HU I (AQ1)
• Figure 19: Isopach Aquitard HU II + HU IV (AT1)
• Figure 20: Isopach Aquifer HU III (AQint)
• Figure 21: Isopach Aquifer HU V (AQ2)
• Figure 22: Isopach Aquitard HU VI (AT2)
• Figure 23: Subwatersheds, Major River Systems
• Figure 24: Recharge / Discharge Zones