The Connected Relationship Between Water and Energy.
Water and energy depend heavily on each other, forming an important nexus that enables human development and environmental health. This statement will become ever more critical in how we approach building our future cities and addressing the update + upgrade needs we have in our present-day cities.
Recent data highlights opportunities to optimize these linked systems for efficiency and resilience. In 2019, the energy sector withdrew over 400 billion cubic meters of freshwater globally - about 15% of total water use worldwide. Power plant cooling alone accounted for 41% of energy's water needs. With climate change altering regional water availability, this reliance creates vulnerabilities. Droughts now force power curtailments, like France cutting nuclear output during 2022’s low river levels. And Mexico City nearing ‘Day Zero’ with water availability and its consequent effects on power.
At the same time, water treatment and distribution utilizes significant energy - approximating 4% of global electricity demand. Supply disruptions like blackouts thus threaten water access, while cost spikes strain utilities. Extreme weather also stresses interconnected infrastructure across both sectors. Mexico City relies heavily on hydroelectric dams, pumping required for water across vast distances in the country and wastewater treatment requirements (which are increasing) are all factors that clearly highlight the water-energy nexus. Integrative analytics and planning provide pathways to navigate these interdependent risks. Upgrading power plant water efficiency could reduce withdrawals over 70%. Meanwhile, stopping leaks in water pipes saves enough electricity to power millions of households annually. Decentralized rain harvesting and wastewater recycling offer supplemental stability. These are the approaches recommended to address the issues in Mexico City.
As climate impacts intensify, optimizing the crucial water-energy nexus through coordinated analysis, policy, and adaptive solutions will bolster the resilience of these indispensable, linked resources. We have the technology and the approaches to ensure that this interconnection is respected even as we grow our cities. What we need is the willpower to do the work.