[Indonesia] Mitigating hydro meteorological hazard impacts through transboundary river management in the Ciliwong River basin In recent decades the Jakarta Metropolitan Area has undergone widespread development and led Indonesia's impressive economic growth. But this development and associated urban sprawl has contributed to undesirable water-resource issues, such as pollution, groundwater extraction, and increased flooding. For example, the major floods in 2002, 2007, 2013, and 2014 have caused billions of dollars of direct and indirect economic damage, the destruction of houses and livelihoods, widespread displacement, and loss of life. The Ciliwung River Basin (CRB) has been a major source of flooding in recent years. With an area encompassing 347km2, the CRB starts upstream at Tugu Puncak located between Bogor and Cianjur Regencies, and runs downstream into the Jakarta Bay area. There has been rapid development within the CRB due to the increasing rate of population in Jakarta, Bogor, Tanggerang and Bekasi City. The floods are of both fluvial and coastal origin, and are worsening due to a large number of drivers, including land subsidence, low drainage or storage capacity in Jakarta's rivers and canals, changes to the climate increasing the frequency and severity of extreme weather events. They are also the result of a rapidly growing population, and land use change causing a growth in economic assets located in potentially flood-prone areas.  Traditional flood control is focused on structural flood protection measures through physical intervention. Modern flood management also considers prevention and addresses institutional and social aspects. It also extends from upstream to downstream areas to cover the whole river basin. However, the Indonesian context is challenging. Indonesia began a process of rapid government decentralisation in 1999 from a formerly strong centralised government structure. Prior to 1999, the state could enforce flood mitigation measures. Decentralisation has shifted authority to the local level, creating fragmentation among institutions at different levels, and making coordination more complex. This study will consider different aspects of current transboundary river management that could positively or negatively influence the functioning of flood management in the CRB. These will include legal frameworks, roles and responsibility-sharing, modelling, data and information sharing in support of flood forecasting and early warning, dialogue and coordination mechanisms, and stakeholder participation. The project draws upon a range of disciplinary expertise, including hydrological processes, disaster risk reduction, urban planning, public policy, disaster resilience, flood modelling and fluid mechanics, hydraulic engineering, and behavioural science. The team will combine analytical methods (e.g., modelling of key physical flood variables, urban risk flood modelling) with empirical methods that are based on the analysis of observed or potential consequences through the use of interviews, questionnaires and focus groups. The project has the support of and will involve several government institutions at national, regional and local levels in Indonesia.  It will also use a community participatory approach that will raise awareness among communities at risk, and also encourage them to hold accountable those actors who are responsible for disaster risk reduction and river basin management. Through these approaches, the results and recommendations from the study will have been co-created, increasing the likelihood of uptake.  The fieldwork and model development will deliver a better understanding of how and why the current transboundary river management arrangements are mitigating or exacerbating flood hazard impacts in the CRB. The recommendations will contribute to improved governance and institutional arrangements in the CRB, and can inform improved models for governance of transboundary river basins elsewhere. The Newton Fund builds research and innovation partnerships with developing countries across the world to promote the economic development and social welfare of the partner countries.