Climate change affects our water resources. Beside a locally shrinking availability also the quality of the drinking water resources changes. Among other factors raw waters are influenced by increasing temperatures and wastewater fractions promoting eutrophication and algal growth. Furthermore, new water resources will be used such as treated wastewater for agriculture or as a drinking water resource to overcome times of water shortage. This means that new concepts of water management and new water treatment techniques have to be developed. The Late Summer workshop 2025 gathers international keynote speakers and young scientists to discuss these future challenges from 21.9.2025 to 24.9.2025 at the Water Works of Langenau. We can expect a vibrant scientific exchange, network building and to spend a nice time in Langenau.