Water efficiency in smart cities: optimising irrigation for public green spaces

Greening initiatives are urban planning strategies that rely on the development of public green spaces supporting multiple urban system functions. In a global water scarcity context, however, green space irrigation is a key aspect. Dynamic optimisation of irrigation plans is one viable answer for water consumption mitigation, which is not widely implemented at municipal levels in the EU. Yet, hydroinformatics-based mature and market-ready methods and technologies can support its implementation and should allow its embedment within the smart-city concept. Here, a simple interoperable approach for optimisation of dynamic irrigation planning has been implemented in public green space parcels of a French Mediterranean coastal city. The approach relies on smart sensors, a water balance model, an optimisation algorithm, and weather forecast data integration, all encapsulated in the standardised and open-source FIWARE ecosystem. The results of the dynamic irrigation plan led to a 35% water saving during the dry season and to more than 60% water saving during the dry-wet season transition period. The used standard technologies and approach could fit a broad range of smart-city digital platforms without any technical challenge. {Graphical abstract}