https://doi.org/10.1007/s40899-025-01286-5

As global populations expand, increasing pressure is placed on agriculture-rich regions and their water supplies under changing climates. The Saskatchewan River Basin (SRB) in the Canadian Prairies supports significant agricultural production, and since the early 1900s irrigation has evolved to become an important part of the sector, improving yields and enabling the growth of high-value crops. Proposed irrigation expansion by the Alberta and Saskatchewan Governments, coupled with the impacts of climate change and risks to traditional livelihoods of First Nations under changing streamflow patterns, necessitates hydrologic analysis of the SRB that dynamically incorporates climate change and irrigation to assess future water security and the viability of current water governance and transboundary water agreements (i.e., the Master Agreement on Apportionment). This study integrates irrigation into a regional implementation of a global hydrological model (HYdrologic Predictions of the Environment, HYPE), which was driven by climate simulations from 1976 to 2070 to investigate the future viability of agriculture expansion policies and existing transboundary water agreements. Results indicate that (1) drier summers are likely to strain irrigation water supply during the growing season; (2) irrigation in the upstream reaches of the basin may lead to reduced streamflow and a loss of seasonality in downstream reaches, with implications for riparian ecosystems and the Saskatchewan River Delta; (3) the system of prior allocation in Alberta puts disproportional water security risk on First Nations under low flow conditions; and (4) compliance with the Master Agreement on Apportionment may become increasingly challenging on the South Saskatchewan River under future low-flow conditions.

https://doi.org/10.1007/s40899-025-01286-5