In 2016, Bolivia experienced the worst water crisis in the last twenty-five years. This crisis, attributed by national authorities to climate change, jeopardized water and food security for the Bolivian population, especially for the most vulnerable sectors in the suburban and rural areas of the country. As a result, rainwater harvesting is emerging as an alternative to increase water security and tackle negative impacts of climate change on water availability. Rainwater harvesting significantly reduces environmental impacts compared with those produced by mainstream water supply interventions, such as large dams, reservoirs and water transportation. This chapter highlights an experience of not-for-profit cooperation between civil society organizations from Bolivia and Brazil searching for alternative solutions to adapt to climate change. In this framework, rainwater harvesting is not isolated as a technical issue; it goes together with the creation of spaces to promote change in the culture of water and natural resource use and how people interact with them collectively.