This Supplement provides municipalities, decision-makers and interested stakeholders with an overview of the main technical aspects that need to be considered to effectively design and implement smart water management in cities. This Supplement approaches smart water management systems from an overarching perspective. Therefore, it is expected that the smart water technologies described, as well as their integration into urban water management systems, can be relevant to inform the design of new systems (e.g. in the case of rapid urban growth and infrastructure extension in developing countries), as well as to update existing systems (e.g. linked to declining per capita demand for water and ageing infrastructure in developed countries).