An Evaluation of Current and Future Water Allocation Strategies in the Saskatchewan River Basin, Canada
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Abstract: Competition among water users for limited water resources has been intensified due to growing water demands and decreasing available water in many regions. Under these circumstances, allocating water among competing users efficiently becomes more controversial, particularly in large and multi-jurisdictional basins like the Saskatchewan River Basin (SaskRB). In the SaskRB, licenses have been issued to allocate water on the “first in time, first in right” basis. In this study, we focus on Alberta and Saskatchewan as the two main provinces that share the Saskatchewan River Basin. Upstream Alberta is facing a challenge of water over-allocation due to extensive developments. Meanwhile, downstream Saskatchewan has not yet used the total amount of water it has claimed and is entitled to. Thus, the Saskatchewan province is planning for new developments that demand more water from the South Saskatchewan River. Therefore, in this presentation, we aim to evaluate the existing water allocation system and assess the economic impacts of alternative water allocation strategies in the Saskatchewan River Basin. Within this context, first, we analyze water allocation and actual withdrawal data in different sectors for the period 2005 to 2016 in the SaskRB to examine the current status of water use in the basin. A GIS data frame is also developed by employing the ArcGIS platform to study the spatial distribution of different water users in sub-basins of the SaskRB. Second, we employ an Input-Output hydro-economic model to study the economic impacts of the existing and alternative future water allocation strategies on the economy of the SaskRB. The Input-Output model is an analytical framework developed based on the Leontief Input-Output model and the Canadian Input-Output tables for the year 2014. This model uses inter-industry relationships in each province to estimate the changes caused by different water allocation strategies. We couple this model with a water resources system model already developed within the MODSIM-DSS framework for the SaskRB that provides us with alternative future water allocation scenarios. Results of our study show that from 2005 to 2016, total annual water withdrawals from the surface water resources in Alberta and Saskatchewan did not exceed 51 and 30 percent of the allocated amount through the licenses, respectively. This study also demonstrates that the amount of agricultural water withdrawal from the surface water resources in Alberta and Saskatchewan provinces had more fluctuations (as expected), compared with the other sectors. Moreover, results indicate that in some of the sub-basins, the ratio of water withdrawals to the entitled water has changed considerably over time. With the existing water allocation strategy, agriculture is the third and 17th biggest contributor to the provincial gross domestic product in Saskatchewan and Alberta provinces, respectively. We evaluate and report how the economy of the region might change under different future water allocation scenarios.