The proposed BALTIC-FLOWS project concerns rainwater monitoring and management in Baltic Sea catchment areas. Rainwater forms streams and rivers, and in urban environments, heavy rainfall can amount to stormwater and floods. Over the years, much of this rainwater ends up in the sea. In Northern Europe, the Baltic Sea conceals a history of water quality from streams, rivers and urban runoff in catchment areas. Encircled by a mix of Nordic, Central and Eastern European countries, the Baltic Sea is at the mercy of a diversity of national practices and policies. The project shall lay the foundation for development of new capacities and policies for effectively monitoring and managing the quality and quantities of rainwater moving from one place to the next. The project focuses on streams, rivers and cities in Baltic Sea catchment areas, not on the sea itself. The strategies, knowledge and expertise created during the project can be exploited elsewhere in the Union and in other global regions. The project will support the development of research-driven clusters in each region; enhanced capacities in diffuse load monitoring and urban stormwater management will lead to new business opportunities in the global market for water monitoring and management know-how and solutions. A total of 47 organisations will be participating in the project: 16 project partners in five European regions - Estonia, Finland, Germany, Latvia and Sweden, one project partner from the UK specialised in the Chinese environmental sector, and 30 supporting partners, including entities in participating regions, entities in the international regions of Russia, China, Vietnam and Brazil, inter-regional financing entities operating in the Baltic Sea region, and a Russian-Belarus collaboration forum. The project primarily addresses domain b) of the REGIONS-2012-2013-1 topic, but is also strongly related to themes in domain a).