Water management is a pressing 21st century problem because human demand for reliable water supplies and environmental quality keep rising. As London’s ‘Global University’, water researchers at UCL work on a host of international water challenges. These include sustainable small-scale provision in South America, water markets in California, robust water treatment methods for poor communities, public acceptability of water reuse in Australia, sustainable transnational aquifer use in North Africa, etc. Water management in England and in London’s Thames basin also leads to fascinating research problems. A high population density combined with relatively low rainfall in South East England leads to excessive water demand during droughts. Local water managers are building a new desalination plant, implementing innovative water demand management programs and trying to establish water markets. Flooding, water quality and ecological habitat protection present further problems. Adapting local water systems to climate change and other uncertain future challenges is a challenge we are addressing through several research projects and partnerships. Our research tackles these real water resource problems and aims to make a difference. Over a dozen PhD students and a large group of MSc students make for a stimulating and productive environment. Expertise from UCL’s other world class researchers in planning, spatial analysis & GIS, hydraulics, hydrology, hydrogeology, statistics, geography, economics, computer science, chemical engineering, operations research, etc. ensure high quality interdisciplinary interactions.