The SmartWater project is developing a digital urban planning tool – the Blue-Green Infrastructure Planner (BGI Planner) – to integrate decentralised stormwater management measures into planning processes at an early stage. The aim is to strengthen the climate resilience of urban areas, mitigate flood risks, reduce urban heat and lessen the pollution of Berlin's waterways. The BGI Planner is based on a modular structure and links geodata, checklists and effect simulations. In two pilot areas in Berlin, the effects of blue-green infrastructure are being analysed using models – in terms of flooding, water pollution, urban climate and water balance. Established modelling tools such as InfoWorks ICM, GERRIS/HYDRAX/QSim, ENVI-met and ABIMO are being used. Initial simulation results confirm the effectiveness of selected measures and form the basis for simplified evaluation models in the tool. In future, the BGI Planner will be used as a digital tool in Berlin's administration to support sustainable and climate-adapted urban development.

SmartWater is a Berlin-wide initiative that integrates blue and green infrastructure measures into urban planning through three digital tools. The tools are being tested in two contrasting districts and comprise of a planning tool, a digital game and a flood information portal. These prototypes demonstrate the potential of blue-green infrastructure to reduce flood risk, mitigate heat stress and enhance urban climate resilience. The development process has been meticulously structured to facilitate a collaborative co-design process involving administrations, utilities, experts and residents. This approach has been instrumental in elucidating the governance needs, data requirements and communication pathways. The findings illustrate the efficacy of coordinated modelling and shared digital infrastructures in facilitating decision-making processes, enhancing public comprehension, and providing a transferable framework for urban areas aspiring to enhance climate adaptation through integrated and pragmatic approaches.

Nature-based solutions (NBSs) are often considered to be cure-all remedies for mitigating risks arising from climate change, among others. This study explores the failure modes of NBSs in stormwater management, and analyses challenges across the different stages of their life cycles, including planning, design, and operation. The PRISMA methodology was applied to carry out a systematic literature review to identify the main triggers, consequences and potential mitigation measures for different failure modes and challenges, with a view to enhancing the long-term performance of NBSs. Each identified failure mode was classified along the three typological dimensions of severity, origin and preventability, with sub-dimensions for qualitative and quantitative analysis. Based on 76 reviewed studies, it was concluded that preventable and intrinsic failures dominate the early stages (planning and design), whereas induced and extrinsic failures tend to manifest during operation and maintenance. The application of interdisciplinary and catchment-scale thinking in planning reduces the probability and severity of failure in the design and operation stages. Standardised and data-based approaches are needed to mitigate NBS failures throughout the life cycle.

Mischwasserüberläufe nach Starkregenereignissen führen in den Berliner Fließgewässern im Sommer regelmäßig zu Sauerstoffdefiziten bis hin zu Fischsterben. Um solche Zustände zu vermeiden, ist neben der Sanierung des Kanalnetzes die Abkopplung von 20 bis 40 % der angeschlossenen Flächen in den Mischwassereinzugsgebieten notwendig und in Planung. Im Projekt MiSa - Mischwassereinzugsgebietssanierung - wurden im Auftrag der Umweltverwaltung in Workshops mit Berliner Bezirksämtern mögliche Abkopplungsstrategien definiert. Zur Bewertung dieser Strategien wurde eine Modellkette aus Kanalnetz- und Gewässergütemodell aufgebaut, die erstmals eine immissionsbasierte Bewertung ermöglicht und damit die Flächenabkopplung in einen direkten Zusammenhang mit der Gewässergüte stellt.

Urban wastewater management and the associated modelling has become indispensable today. Reliable calibration is essential for these models, and water level data is used as a standard. However, data collection can be limited due to high sensor costs and harsh conditions in the sewer. A novel solution is collecting data using low-cost temperature sensors, placing one in the stream, the other at the crest of the weir. In the case of dry weather, the sensor measures the air phase, whereas, in the case of Combined Sewer Overflow (CSO), the discharged storm and wastewater is measured. Autocalibration was performed using OSTRICH for a SWMM model in Berlin, with water level and fictional temperature data, and various number of measuring sites. Results showed that calibration using temperature data was as good as using water level data, with promising outcomes achieved by using one measuring site, offering a cost-effective alternative for water utilities.