Water recycling and reuse can overcome water resource problems efficiently and sustainably by creating an alternative source of high-quality local water supply and thus partially replacing already scarce freshwater resources. In particular, the reuse of qualitatively impaired surface water or further treated (municipal) clear water can effectively mitigate the challenges associated with increasing water use conflicts. In May 2020, the EU published a new regulation on minimum requirements for water reuse for agricultural irrigation for the first time. This also came into force in Germany in June 2023 and is currently being transposed into national law. In addition, the DWA has for the first time drawn up a set of technical regulations for water reuse (DWA-M 1200), which will be published in yellow print in 2025. Due to this development, but especially due to the noticeable consequences of climate change, there is now also a great need for action for water reuse in Germany. Based on a feasibility study in Lower Franconia, we were able to start the new BMBF joint project ’Nutzwasser ’ in 2021, which is developing concepts for safe water reuse for urban and agricultural irrigation on a demonstration scale. We will complete this project at the end of 2024. Based on the findings of this study, the city of Schweinfurt will be the first city in Germany to implement the use of industrial water for urban greenery in the city. We are very grateful for the funding from the Bavarian Ministry of the Environment.
In addition, water reuse is an interesting support option for artificial groundwater recharge. Also funded by the BMBF, we have been testing the concept of sequential managed aquifer recharge technology (SMART) on a former waterworks site together with Berliner Wasserbetriebe as part of the ’TrinkWave Transfer’ project since 2022. We are also able to continue this project with European partners in the ’MARSURE’ project thanks to follow-up funding from an EU program. We are also investigating the SMART concept for decentralized water reuse as part of an international project in South Africa funded by the Bavarian Ministry of the Environment.