Progressing climate change significantly affects the quality of life in cities. The related changes in the rainfall structure lead to an increased frequency of extreme hydrological phenomena such as droughts and floods. The increasing intensity of rainfall is a particular threat to urbanised areas, where due to the high degree of area sealing, an increase in runoff volumes and peak flow rate is observed. Storm water drainage systems are often not adapted to accommodate increased rainwater flows, which leads to the so-called urban floods. On the other hand, prolonged periods without precipitation may, in turn, lead to periodic water shortages. Cities must implement a climate change adaptation strategy. One of the solutions for rational rainwater management is the implementation of Blue-Green Infrastructure. These facilities are a modern solution supporting the sewage networks operation, water retention, and improving the quality of life in cities. The article presents the literature review on the current state of knowledge about Blue-Green Infrastructure and the implementation stage of these solutions in the world. Solutions that are newly introduced, not necessarily newly invented, in many places around the world are described. The literature review was limited to the period 2018–2023 to indicate the most modern and up-to-date strategies.

Stormwater drainage from urbanised areas has gained importance due to progressing land surface sealing and climate change. More frequent extreme rainfall events lead to overloaded drainage systems and flash floods, particularly in industrial zones experiencing rapid development. The study analysed the sewage system operation in the Special Economic Zone (SEZ) in Lower Silesia, Poland to assess the impact of climate-induced rainfall changes. Three rainfall scenarios were used: model rainfall using historic rainfall intensities, model rainfall using actual intensities, and real precipitation recorded in June 2022. Findings indicate that climate change has negatively affected the stormwater drainage system, resulting in increased overloads and flooding. Particularly, the II scenario showed a significant rise in rainwater inflow to retention reservoirs by 53.1% for ZR-1 and 44.5% for ZR-2 (compared to the I scenario). To address these issues, adaptations are needed for increased rainwater flows, including additional retention facilities, blue–green infrastructure, or rainwater harvesting for the SEZ needs.

Considering progressive climate change and decreasing water resources, rainwater harvesting is gaining popularity as an alternative water source. This research presents the concept of sustainable rainwater management at the Wrocław University of Science and Technology (Poland). In the proposed solution, rainwater collected in a tank will be used for watering green areas. The Yield After Spillage model was used for analyzing the rainwater harvesting system operation, based on water demand (10 m3/day) and rainfall data for the 2000–2021 period. Simulations were performed for 14 tank sizes (from 10 to 140 m3). For each variant, annual needs coverage, water savings and investment costs were calculated. The results indicated that the most attractive in terms of both return period and mains water savings were tanks with intermediate capacities, with the best variant having a capacity of 60 m3 (corresponding to 6 days’ demand), allowing for mains water savings of 77.2% on average.