HYDROLOGICAL CHARACTERIZATION OF THE STURGEON RIVER WATERSHED IN NORTHEASTERN ONTARIO: A HYDROMETR IC AND WATER ISOTOPE ANALYSIS (Thesis Format: Manuscript) BY NANCY ENGLAND GRADUATE PROGRAM IN ENVIRONMENTAL SCIENCE A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ENVIRONMENTAL SCIENCES SCHOOL OF GRADUATE STUDIES NIPISSING UNIVERSITY NORTH BAY, ONTARIO APRIL, 2017 © NANCY ENGLAND, 2017 Abstract The Sturgeon River is a large watershed (~7000 km 2) located in northeastern Ontario and is a major headwater system of Lake Nipissi ng. River flow and lake levels are managed to balance a variety of environmenta l, social, and economic factors, as well as for the production of hydroelectric power, as described by the St urgeon River Water Management Plan. The objectives of the study were to compare the infl uence of the controlled (e.g. Lake Temagami) and uncontrolled subcatchments on resultant flow downstream; review 1979 (flood), 2010 (drought), and 2013 (contemporary year with wa ter isotope sampling) in the context of hydrologic history; and, explor e relationships between hydrol ogic characteristics and water isotope analysis during 2013, and recommend how information gained from water isotope tracers may improve future operation of the watershed. The historical hydrologic anal ysis involved the comparison of reservoir drawdowns, annual hydrographs, monthly boxplots, flood frequencies, and flow durati on curves, for river flow and dam outflow data at six different sites across the watershed. A calcu lated inflow data set was also prepared and the same metrics were compare d, to determine the relative influence of 3 hydroelectric reservoirs. In addition, the flow and meteorological conditions of two hydrologically significant spring freshets, the 1979 flood and drought of 2010, were compared to the study year (2013). To broaden the analysis of 2013, stable isotope samples were collected from selected locations within the watershed. Results of both hydrometric and isotope analys es showed the varying influence of the reservoirs on the system through each season. Anal ysis of controlled catchments revealed that i during winter months, flows were augmented downstream through reservoir drawdowns, while peak flows were reduced during the spring. Analysis of hydrologically significant years 1979 (flood) and 2010 (drought) illustrate two extreme categories of hydrologic response and meteorological scenarios that management activities were unable to prevent. The separation of flow peaks from southern and northern melt events was found to be the difference between the 1979 and 2013. In 2013 freshet flow was found to be driven by a combination of rain and snowmelt. Spatial differences in rain and timing of melt were found to allow the southern portion of the watershed to melt and flush through the system, while the northern portion melted after the initial flow peak at Crystal Falls (415.6 m3/s on April 21). The analysis of isotope values through the freshet showed a clear separation between the southern melt period and the initiation of melt from the northern portion of the watershed. Through the summer, reservoirs in the east became increasingly enriched in δ18O and δ2H while flow from the western portion of the river remained fairly stable due to groundwater driven baseflow. The influence of reservoirs on isotope values within the river decreased with distance downstream from the confluence of the Sturgeon and Temagami Rivers near River Valley. Isotope tracers were found to be a useful tool for the evaluation of inputs to the Sturgeon River and the timing and changing influence of different branches of the system. They were also useful in identifying the impact of groundwater interactions, which are not captured by traditional hydrometric analysis. Long-term monitoring using isotope tracers would help characterize the hydrology of the system, to gain deeper insight into seasonal trends. ii Keywords Isotope hydrology, stable water isotopes, hydrologic metrics, hydroelectric, reservoir, inflow, mass balance, Sturgeon River, Canada iii Co‐Authorship Statement In this manuscript, Dr. A. James of Nipissing University will be listed as co-author because of her involvement in the conceptual development of the research, structure and editing of the thesis, and contribution to the field and laboratory measurements of δ18O and δ2H; Dr. Rich Pyrce for critique of the hydrologic and methodological approach, and editing; and Dr. K. Chutko of Nipissing University for his contribution to the field campaign design, the collection of samples, and analysis of laboratory measurements of δ2H and δ18O. iv Acknowledgements Thank you to Nipissing University, Canada Foundation of Innovation, and the Canada Research Chair program for providing the funding and resources to make this research possible. Thank you to Ontario Power Generation for your data, resources, and time. Thank you to Krys and Brittany for making the field component so thorough and enjoyable. Thank you to April and Rich, for the significant investment of time, patience, and encouragement. Most of all, thank you to my friends, family, and Jenna; you keep me going. v Table of Contents 1 Introduction .................................................................................................................. 1 2 Literature Review ......................................................................................................... 5 2.1 Reservoir Influence and Watershed Analysis Metrics............................................... 5 2.2 Isotope Fundamentals ................................................................................................ 9 2.3 Large Scale Watershed Studies Using Water Isotopes as Tracers .......................... 12 2.4 Isotope Studies on Large Hydroelectric Systems .................................................... 16 3 Study Site .................................................................................................................... 17 4 Methods ...................................................................................................................... 19 4.1 Flow & Meteorological Data ................................................................................... 19 4.2 Hydrometric Analysis .............................................................................................. 22 4.3 Sampling and Analysis of Stable Water Isotopes in 2013 ....................................... 25 4.3.1 Spatial and Temporal Campaign ..................................................................... 25 4.3.2 Sample Collection & Quality .......................................................................... 28 4.4 Isotope Calculations ................................................................................................ 29 4.4.1 Groundwater Mixing Analysis ........................................................................ 29 4.4.2 Discharge Anomaly ......................................................................................... 30 5 Results ........................................................................................................................ 31 5.1 Hydrologic Analysis ................................................................................................ 31 5.2 Comparison of 1979, 2010, and 2013 ...................................................................... 35 5.3 Water Isotope Storyline of 2013 .............................................................................. 40 5.3.1 2013 Water Isotope Study ............................................................................... 40 5.3.2 Temporal & Spatial Analysis of Isotope Samples ........................................... 42 5.4 Mixing Analysis ...................................................................................................... 49 5.5 Discharge Anomaly ................................................................................................. 51 6 Discussion ................................................................................................................... 51 6.1 The Significance of Storage .................................................................................... 51 6.2 Sturgeon River Water Management & the Classification of System Response ...... 55 6.3 Use for Large Scale Watershed Applications .......................................................... 57 7 Conclusions ................................................................................................................ 59 8 References .................................................................................................................. 62 9 List of Tables .............................................................................................................. 68 10 List of Figures ............................................................................................................. 87 vi Appendix A – North Bay & Sudbury Climate Normals.................................................... 111 Appendix B – Water Isotope Results ................................................................................ 125 Appendix C – Precipitation Sample Volumes ................................................................... 143 Appendix D – OPG, MNRF, and NU Snow Data ............................................................. 145 Appendix E – Isotopic Sample Result Precision & Accuracy .......................................... 175