Background to the Saskatchewan River Basin

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Phillip Burke
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1 Background to the Saskatchewan River Basin Professor John Pomeroy Canada Research Chair in Water Resources & Climate Change, Centre for Hydrology, University of Saskatchewan, Saskatoon Canada

2 Saskatchewan -Nelson River Basin flows east across Alberta, Saskatchewan and Manitoba to Hudson Bay

3 Canadian Rocky Mountains

4 Irrigation 70% of consumption of South Saskatchewan River goes to irrigation. 5% of Alberta farmland is irrigated but produces 20% of gross provincial agricultural production

Canadian Prairie Agriculture: mostly dryland grain farming & pasture Cold, continental, semi-arid climate Precipitation on average 350 mm Grain Growing

5 Canadian Prairie Agriculture: mostly dryland grain farming & pasture Cold, continental, semi-arid climate Precipitation on average 350 mm Grain Growing 125 mm soil water reserves needed from snowmelt 175 mm spring rainfall needed Roughly 300 kg/ha increased wheat yield for each extra 25 mm of water added

6 Runoff Non-Contributing Areas to Streamflow a Prairie Characteristic

7 Prairie Provinces Water Apportionment Agreement 1948 Agreement between Governments of Alberta, Saskatchewan, Manitoba and Canada, establishes Prairie Provinces Water Board (PPWB). 50% of annual natural flows of waters arising in each province in each major river basin as streamflow are to be permitted to flow across provincial borders. Absolute minimum flow guaranteed (but extremely low). Groundwater and water quality are also considered. Streamflow monitoring is operated and archived by the Water Survey of Canada at border crossings. Natural flows are estimated as the water that would flow in a river if consumption for agriculture and municipal consumption were returned to the river. Regular meetings of PPWB to assess measured flows and calculated naturalized flows to ensure compliance to the Agreement and discuss collaborative projects to better manage and understand water resources in the region.

8 Current Challenges to the PPWB: Authorities over water are shared amongst jurisdictions; Actions in one jurisdiction may affect other jurisdictions; The volume and timing of flows in streams that originate in the Prairies are highly variable throughout the year and from year to year; Water use and consumption in southern Alberta and south-western Saskatchewan is a large percentage of available supply and may have prior water rights (Alberta); Population and economic activity are increasing; Climate change will affect timing and volume of available water; Monitoring is considered insufficient and must be rationalized within existing budgets;

9 Issues for Water Management Drought, Floods Climate change Warming Wetting or drying??? Changes to nature of precipitation Forest cover change Reforestation over last century Pine beetle caused deforestation now Water use increasing Irrigation Municipal and industrial consumption

10 Alberta South Saskatchewan River Use Approaches Entitlement in Droughts

11 Climate Change: Variation among model simulations Seasonal changes in mean temperature ( C) and precipitation (%) for the grassland region of Saskatchewan. From Climate Scenarios for Saskatchewan, Elaine Barrow, PARC ( April 2009

12 Rocky Mountain Snow vast water reserves in winter snowpack southernmost, interior summer snow water reserves Snow depth in January Snow depth in June

13 Snowpack Trends

14 Demuth Columbia Icefield

15 Change in Flow of Major Rivers Upstream mountain water supply driven by changes in snow accumulation, snowmelt and snow covered period in winter and spring. Downstream river flow reduced by water consumption on the Prairies How much will it change in the future? Why?

16 Mean Yearly Flow m3/sec Problem: Water Resources are Changing. Where, How Fast, Why, How Much More? 60 Bow River at Banff, Mean Annual Flow Trend -11.5% since 1910, Statistically Significant at 99% Probability Year

17 NATURAL FLOWS OF THE SOUTH SASKATCHEWAN RIVER LEAVING ALBERTA Annual Flow m 3 18,000,000,000 16,000,000,000 14,000,000,000 12,000,000,000 10,000,000,000 8,000,000,000 6,000,000,000 4,000,000,000 2,000,000, Year Highly variable

18 Deforestation

19 Natural and Actual Flow of South Saskatchewan River leaving Alberta Annual Flow m 3 18,000,000,000 16,000,000,000 Natural Actual 14,000,000,000 12,000,000,000 10,000,000,000 8,000,000,000 6,000,000,000 4,000,000,000 2,000,000, Year Natural flow: Decline of 1.2 billion m 3 over 90 years (-12%) Actual flow: Decline of 4 billion m 3 over 90 years (-40%) Note: 70% of decline due to consumption, 30% due to hydrology Upstream consumption: 7%-42% of naturalized flows in last 15 years

20 Integrated Observing & Predicting Systems Current high altitude observation network in Canada is inadequate, need a network of stations, remote sensing, modelling, data assimilation in order to predict our cold regions water resources adequately.

21 Concluding Remarks Improved observations, data assimilation, and modelling and are needed in order to manage a resource under pressure. Saskatchewan River hydrology is a consumed and managed system. Great uncertainty as to changes in river basin function due to Changes in climate Changes in land use Changes in consumption and management

Ensuring Sufficient Water Supply for the Emerging Bioeconomy

Ensuring Sufficient Water Supply for the Emerging Bioeconomy John Pomeroy & Michael Solohub Canada Research Chair in Water Resources & Climate Change & Centre for Hydrology, University of Saskatchewan