Global energy consumption of inter-basin water transfer megaprojects

Between two and three billion people experience water scarcity for at least one month per year, posing severe risks to livelihoods. Inter-basin water transfers (IBWTs) have been used to address water scarcity, supporting the economic development of recipient basins. IBWTs often provide water for multiple sectors, such as drinking water supply and food, energy and industrial production. However, IBWTs have significant adverse impacts during and after their construction, including community displacement, depletion of water resources in donor basins, introduction of invasive species and environmental pollution. Furthermore, it is recognized that these transfers can be energy intensive when water is pumped uphill to cross mountain ranges from donor to recipient basins, resulting in localized energy demands at pumping stations. Yet, a detailed analysis of their energy consumption at the global scale is currently lacking.

In this research, we therefore aimed to build a framework to calculate the energy consumption of IBWTs globally. We collected data concerning the paths, topography and infrastructure of 40 such megaprojects across the globe to quantify the elevation changes traversed by each IBWT. Then, a novel dataset with modelled time series of monthly reservoir discharge (1979-2023) was matched onto the transfer paths to evaluate the amount of water that was moved over time. We use these data as inputs for a physical model of energy consumption for water pumping of IBWT.

Results obtained with the newly developed model framework enable us to understand the influence of infrastructure development on the energy consumption of IBWTs in various regions globally. The gridded outputs of our model framework can be used for the spatial representation of energy consumption of IBWTs in Integrated Assessment Models and Energy Supply Models. Future work aims to expand the dataset to smaller scale inter-basin water transfers, and evaluate the tradeoffs between expanding global clean water provision and mitigating anthropogenic climate change.