Groundwater – Surface Water Interactions in the Discrete Fracture Networks of Bedrock Rivers by Celia Sylvia Cassis Kennedy A Thesis presented to the University of Guelph In partial fulfillment of requirements for the degree of Doctor of Philosophy in Environmental Sciences Guelph, Ontario, Canada Celia Sylvia Cassis Kennedy, June, 2017 Abstract Groundwater – Surface Water Interactions in the Discrete Fracture Networks of Bedrock Rivers Celia Sylvia Cassis Kennedy Advisors: University of Guelph, 2017 Professor Beth Parker Professor Gary Parkin Professor Emmanuelle Arnaud Bedrock rivers exist where surface water flows along an exposed riverbed aquifer, but little is known about their physical and chemical properties. Groundwater and surface water are linked at the streambed interface, leading to shared sustainability issues. The sharing of common pathways into and out of the streambed fracture networks provides opportunity for the exchange of thermal, chemical and biological constituents, affecting water quality and ecosystem health. Alluvial rivers exhibit granular beds and their flow patterns are well understood. Much of our water-resource management decisions are based on alluvial river conceptual models using an equivalent porous media (EPM) approach. Since bedrock rivers are more challenging to instrument, their complex flow patterns have not been addressed in the discrete fracture network (DFN) context, thus, there is a gap in the literature. This is the first study of a bedrock river yielding a field-based conceptual model of the spatio- temporal variability of groundwater fluxes and head differentials between groundwater and surface water in the upper 0.30 m of an intact dolostone streambed. A field site along the Eramosa River, in Guelph, ON, Canada, was developed, where the longitudinally-stepped profile of a bedrock riffle-pool sequence exists within a channel meander. The new field site was heavily instrumented with an innovative monitoring system designed for use along vertical and bedding plane riverbed fractures. Thus, a three-fold contribution has been made, to advance our understanding of bedrock river flow systems, including: the design of tools for measuring hydraulic parameters, the development of a field site to test them, and the spatio-temporal conceptualization of groundwater – surface water exchanges along an intact bedrock river channel and glaciofluvial plain. ii Groundwater flow (푄) measurements ranged from -0.4 – 55 mL/min, with uncertainties of 13 – 40%. Fluxes (푞) of 0.12 – 0.99 m/day and average linear groundwater velocities (푣̅) of 7 – 985 m/day were estimated from flow. Relative head differentials (∆ℎ푟푒푙), measured under suction between groundwater and surface water, ranged from 0.001 – 0.023 m 0.001, and vertical hydraulic gradients (∆ℎ푟푒푙⁄∆퐿) ranged from 0.02 – 0.46. Groundwater velocities in a bedrock river were observed to be influenced by: (1) proximity to a vertical fracture, (2) topographic relief or elevation, (3) channel geometry and (4) regional boundary conditions. iii Acknowledgments Sincere thanks to advisory committee members, Dr. Beth Parker, Dr. Gary Parkin and Dr. Emmanuelle Arnaud for your time, editing efforts, scientific inputs and continued support. Special thanks to Dr. Parker for your efforts as principal investigator of the broader field research program, which made my work possible, and for numerous discussions, insights and access to resources during my pursuit of a field site, a research topic and with tool design/construction. Special thanks to Dr. John Cherry for your insights and encouragement during field site and portable drill selection, with tool design and for sitting on my examination committee. Thanks to both Dr. Parker and Dr. Cherry for your guidance and feedback on my many presentations and progress updates that were required during the course of this research. Sincere thanks to Dr. William Woessner for serving as external examiner. The author gratefully acknowledges the funding support of: (1) Dr. Parker, NSERC Industrial Research Chair, (2) Dr. Cherry's NSERC Discovery Grant, (3) MEDI Ontario Research Excellence Fund Round 3 Project, (4) Grand River Conservation Authority Holmes Scholarship, and (5) University Consortium for Field-focused Groundwater Contamination Research. I would like to recognize key support from: (1) Scouts Canada, for continued access to the Barber Scout Camp, Guelph, (2) Robert Ingleton, University of Waterloo, for your technical expertise, creativity and sense of humour in working through one design problem at a time with me, (3) Dr. Brewster Conant Jr., University of Waterloo, for collecting the infrared data and teaching me how to process it, (4) Art Timmerman and the Ministry of Natural Resources for your support and approval of the riverbed installations, (5) Grand River Conservation Authority, for access to streamflow data from the Water Survey of Canada Gauging Station at Watson Road, Guelph, (6) Dr. Patryk Quinn for many discussions regarding hydraulic test analysis methods and your edit inputs in Chapter 2, (7) Dr. Colby Steelman for your collaboration with parallel studies and your edit inputs in Chapter 3, (8) Dr. Peeter Pehme for your assistance with geophysical equipment and WellCAD software, (9) Jonathan Munn and Carlos Maldaner, Ph.D Candidates, for sharing your insights and your time to trouble-shooting field and software iv challenges, (10) Dr. Jessica Meyer and Dr. Ben Swanson for your insights and assistance with ArcGIS software and preparing for my qualifying exam, (10) Steven Chapman, MSc., for discussions and insights regarding hydraulic test analysis methods, (11) Dr. Jon Warland, University of Guelph, for access to rainfall data from the Environment Canada Automated Climate Station at Guelph Turf Institute, (12) Dr. Andrea Bradford, University of Guelph, for the loan of your flow meter, (13) Aardvark Drilling for your expert collaboration with implementation of our new portable drill studies, (14) Van Harten Surveying for collecting many many GPS point measurements in the river with me, (15) Tom Koby, Koby Environmental, for working through the J-Plug modifications with me, (16) Emile Dijkstra at Schlumberger Water Services, for help with transducer programming, (17) Carl Keller and Ian Sharp, Flexible Liner Underground Technologies, for your help with FLUTe profiling and customized liners for small-diameter coreholes, (18) Dr. Thomas Doe, Golder Associates, for use of FracMan software v.7.5, and (19) Joshua Kennedy, EIT, Lakehead University, for the original BSM technical drawing. Sincere thanks to my second family, the G360 Groundwater Gang. This diverse project brought out the best in people during some pretty adverse conditions in the field. It has truly been a pleasure to work with such a kind and dedicated group of individuals – something the world needs more of. Special mention of the field crew: Donovan Capes, Andrey Fomenko, Jon Munn, Carlos Maldaner, Colby Steelman, Tom Coleman, Dan Elliot, Tammy Zidar, Joanna Olesiuk, Carla Rose, Tara Harvey, Amanda Malenica, Paul Trudell, Paulo Casado, Keelin Scully, Rachael Harman-Denhoed, Ben Kennedy, Helene Thuret, Doug Miller, Jessica Power, Jeff Martin and Chris Morgan. Heartfelt thanks to my sons, Joshua and Benjamin, for their love, support and helping hands at home, in the lab and in the field over the years. And to my husband (the most patient man in the world), who convinced me to leave the legal field and go back to school seventeen years ago. Bryan, you promised we wouldn't end up living in the streets and you have stood by me through it all; I cannot find the words. v Declaration of Work Performed I declare that, with the exception of the items listed below, all work presented in this thesis was performed by me. Dr. Beth Parker and Dr. John Cherry drew the first BSM on the back of an envelope during the University Consortium Fall Focus Meeting in Denver, Colorado, in 2012. Robert Ingleton, Senior Field Technician, University of Waterloo, performed the physical construction of the BSMs, the drag probe, the piezometer casings, and the river stage gauges, and worked through practical design and installation challenges with me. He also performed the physical drilling of all river piezometers and stage gauges, and twelve of the BSMs. Andrey Fomenko, MASc, G360 Institute for Groundwater Research, University of Guelph, collected downhole geophysical logs in the floodplain wells. He also performed the physical drilling of twelve of the BSMs. Donovan Capes, BSc, G360 Institute for Groundwater Research, University of Guelph, performed the physical construction of the customized potentiomanometer and assisted with riverbed drilling. Dr. Brewster Conant Jr., University of Waterloo, collected the aerial infrared and video images of the 12- km reach of the Eramosa River. Jon Munn, PhD Candidate, G360 Institute for Groundwater Research, University of Guelph, provided insights as to the location of the floodplain wells from his thesis work on inclined coreholes and the regional fracture orientation. Dr. Colby Steelman, PDF, G360 Institute for Groundwater Research, University of Guelph, provided insights as to the location of the floodplain wells from his surface geophysical surveys of the study site (i.e., ground-penetrating radar and surface electrical resistivity). Aardvark Drilling, Guelph, Ontario, completed the drilling of all floodplain wells with the assistance of Robert Ingleton and Dan Elliot, Field Technicians, using drilling equipment owned by