Water is not only at the core of different public services cities provide, including application and sanitation, water also acts as a carrier of nutrients and energy which can benefit other urban systems. However, Global demand for freshwater will exceed viable resources by 40% by 2030, if we continue with business as usual (ARUP). Exploring the synergistic link between water, food and energy in urban systems becomes central to sustainable development and the sustainable management of water. Urban changemakers in all three areas should start taking a more holistic approach to water management—from water resource management, to ecosystem protection and water supply and sanitation (UN Water).

Bringing circularity within the food-water-energy nexus means recognising all urban water flows—drinking water, stormwater, wastewater and source water—as potential resources for use across these three sectors. Circular water systems can maximise synergies between food water and energy systems by protecting water availability to maintain agricultural production in water scarce regions, or by recovering energy from wastewater treatment, replacing fossil fuels used for cooking or heating. Solid organic matter, or biosolids, recovered from a sewage treatment can also be used as a fertiliser, preventing harmful chemicals from polluting water streams so that water sources are clean and safe to drink.

Local governments can govern the food-water-energy nexus by looking holistically at the city’s infrastructure. They can update city plans to integrate Green Blue Infrastructure (GBI) which can provide tangible benefits to each dimension of the food-water-energy nexus. Parks, green walls, waterways and greenways can, for example, provide food, water, fibre and fuel to support the urban ecosystem. Moreover, bringing different actors together, from the department of water resources, food safety, as well as energy and planning, is at the heart of any form of integrated planning. To spur cross-sectoral collaboration, for instance, cities can convene different actors on dedicated platforms and facilitate effective communication between different city departments and public organisations. Embedding a nexus strategy in municipal policy may lay a foundation for cross departmental budgeting and program implementation.