Rainproof is a network in Amsterdam in the Netherlands aiming to make the city rainproof by 2050 by activating all parties that can contribute to this objective. 'Rainproof', in this understanding, means enhancing the city's sponge capacity by increasing the places and areas where rain can go during heavy rain events and avoiding potential damages. Alternatively, excess water can be stored and re-used (e.g. to flush toilets or to water gardens) through green roofs, water roofs or ponds on private and municipal properties. Starting in 2014, the network is comprised of a mix of government institutions – including the municipality of Amsterdam – neighborhood initiatives, knowledge institutes, residents, and private businesses and entrepreneurs. The strategy to achieve a rainproof city is to use the network to share knowledge and information, refer and connect people, and initiate and support projects, some of which focus on nature-based solutions as natural drainage solutions to prevent flooding.