Science, Assessments and Data Availability Related to Anticipated Climate and Hydrologic Changes in Inland Freshwaters of the Prairies Region (Lake Winnipeg Drainage Basin) David J. Sauchyn and Jeannine-Marie St. Jacques Fisheries and Oceans Canada Freshwater Institute 501 University Crescent Winnipeg, MB, R3T 2N6 2016 Canadian Manuscript Report of Fisheries and Aquatic Sciences 3107 i Canadian Manuscript Report of Fisheries and Aquatic Sciences Manuscript reports contain scientific and technical information that contributes to existing knowledge but which deals with national or regional problems. Distribution is restricted to institutions or individuals located in particular regions of Canada. However, no restriction is placed on subject matter, and the series reflects the broad interests and policies of Fisheries and Oceans Canada, namely, fisheries and aquatic sciences. Manuscript reports may be cited as full publications. 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Canadian Manuscript Report of Fisheries and Aquatic Sciences 3107 2016 Science, Assessments and Data Availability Related to Anticipated Climate and Hydrologic Changes in Inland Freshwaters of the Prairies Region (Lake Winnipeg Drainage Basin) by D. Sauchyn1 and J. St. Jacques1 Fisheries and Oceans Canada Freshwater Institute 501 University Crescent Winnipeg, MB, R3T 2N6 1 Prairie Adaptation Research Collaborative, University of Regina, Suite 120-2 Research Dr. Regina, Saskatchewan, S4S 7H9 iii © Her Majesty the Queen in Right of Canada, 2016. Cat. No. Fs97-4/3107E-PDF ISBN 978-0-660-06484-0 ISSN 1488-5387 Correct citation for this publication: Sauchyn, D., and St. Jacques, J. 2016. Science, Assessments and Data Availability Related to Anticipated Climate and Hydrologic Changes in Inland Freshwaters of the Prairies Region (Lake Winnipeg Drainage Basin). Can. Manuscr. Rep. Fish. Aquat. Sci. 3107: vi + 69 p. iv TABLE OF CONTENTS ABSTRACT ...................................................................................................................... vii RÉSUMÉ .......................................................................................................................... vii Executive Summary ............................................................................................................ 1 Introduction ......................................................................................................................... 3 Climate and Water .............................................................................................................. 5 Recent Trends in Climate and Freshwater Resources ......................................................... 7 Temperature .................................................................................................................... 7 Precipitation .................................................................................................................. 10 Surface Water ................................................................................................................ 12 Longer-term surface water trends ................................................................................. 21 Future Climate and Hydrology ......................................................................................... 24 Climate Change Scenarios ............................................................................................ 25 Streamflow .................................................................................................................... 35 Lake Winnipeg .............................................................................................................. 38 Implications of Climate Change for the Inland Freshwaters of the Prairies Region ........ 40 Surface Water Quantity and Quality ............................................................................. 40 Groundwater ................................................................................................................. 41 Floating Freshwater (Lake and River) Ice .................................................................... 42 Climate Change and Water Management ......................................................................... 48 Conclusions ....................................................................................................................... 50 References ......................................................................................................................... 51 Appendix A: Trends in annual (or warm season) flow for 86 naturally flowing and five regulated streamflow records from the Prairie Provinces (from St. Jacques et al. 2012). 62 TABLES Table 1: Global Climate Modelling Centres (Barrow 2010) ............................................ 24 Table 2: Regional – Global Climate Model combinations available from NARCCAP. (Barrow 2010) ........................................................................................................... 26 Table 3: Mean and standard deviation of break-up [B(N)50 and B(S)50] and freeze-up [F(S)median] estimated by regression on the date when the 40-day moving average air temperature warmed to +5 (dropped below -5oc for freeze-up) using the record at Berens River for 1976-89 and output CGCM2 (scenarios A2 and B2) for the periods 2040-42 and 2076-88. (McCullough 2005) ............................................................ 45 Table A.1: The 86 naturally flowing and five regulated streamflow records from the Prairie Provinces (St. Jacques et al. 2012). ............................................................... 62 v FIGURES Figure 1: Map of the drainage basins of the Prairie Provinces. The Saskatchewan, Winnipeg, Assiniboine and Red Rivers drain into Lake Winnipeg. (Byrne et al. 2010) ........................................................................................................................... 5 Figure 2: Mean annual temperature records from across the Prairie Provinces for the period 1895-2005. (Sauchyn 2010)............................................................................. 8 Figure 3: Trends in seasonal mean Tmax (a) and Tmin (b) during 1961–2003 in the LWW at the 5% significance level. (Dibike et al. 2012) ............................................ 9 Figure 4. Positive and negative departures from mean annual precipitation, Medicine Hat, Alberta, 1895-2006. (Sauchyn 2010) ........................................................................ 10 Figure 5: Trends in seasonal precipitation (1961–2003) in the LWW at the 5% significance level. (Dibike et al. 2012) ..................................................................... 11 Figure 6: Annual PDSI from 1900 to 2007 for Saskatoon, SK. (Sauchyn and Bonsal, in press). ........................................................................................................................ 12 Figure 7: Prairie lakes 1820 – 2011: Devil’s Lake (ND) is rising since 1940 while nearby Canadian prairie lakes (Kenosee) were falling, until recently (van der Kamp et al.