In the circular economy, water plays many roles as an enabler. One is water as a carrier of materials and energy. Wastewater, especially industrial wastewater, can be a source of materials such as chemicals and nutrients. For example, refinery wastewater has proven to be a source of potassium hydroxide that can be reused. Water also has embedded energy that can be recovered for other uses. Water is a renewable resource, but it is very unequally distributed and increasingly scarce as a result of urbanization and climate change. A comprehensive suite of solutions exist to respond to these challenges, ranging from leakage reduction in water distribution networks to wastewater reuse: Only 2% of all water is reused globally, but recycled wastewater is the only resource that grows with the needs. Reusing wastewater increases the productivity of the abstracted water, typically in agriculture, enabling to grow ‘more crops per drop’. Reuse technologies are also selectively utilized by oil and gas companies in extracting hydrocarbons, reducing both water use and environmental impact.