Where Cities Get Their Water

By 2050, there will be an additional 2.8 billion people living in urban areas globally. Meeting the demand of cities for water will be a challenge for human-created infrastructure as well as for the natural ecosystems. However, where this challenge will be hardest to meet and the severity of potential shortages is still not fully known for most of the world’s cities. Indeed, there is no consistent global dataset of where and how cities obtain their municipal water supply (e.g., surface versus groundwater, near versus far away), nor where the urban poor, who often do not have reliable access to municipal supplies, obtain their water. Without this basic data, it is impossible to estimate urban populations’ dependence on freshwater ecosystem services (e.g., from the watershed above a reservoir), or the potential impact of climate change on these services. We propose a Pursuit that will create such a database. Our first meeting will be a workshop, inviting experts in the fields of ecology, hydrology, demography, urban planning, civil engineering, and economics to help design the database structure so that it will answer key policy-relevant questions. We will also ensure that the experts invited have access to the major extant national or regional databases of urban water use, so we can begin to synthesize these datasets. Subsequent meetings by the core Pursuit team will coordinate actions to finish the database assembly and begin using the database to answer key scientific research questions and craft high-impact manuscripts.