Water scarcity and extreme weather events are already a reality in the sub-basin of the Sumpul River, shared by Honduras and El Salvador, and will likely worsen as the impacts of climate change intensify. This makes adaptation responses necessary to increase the resilience of production systems and ensure water provision. To achieve this, 3 axes of work were combined: strengthening capacities and knowledge through an “action learning” approach; increasing the resilience of ecosystems and livelihoods by implementing ecosystem-based adaptation measures (EbA); and revitalizing the governance of the sub-basin. This led to the analysis of community vulnerabilities; the application of EbA measures in farms adjacent to water sources; the strengthening of the governance and management capacities of local authorities; the articulation of actions through the sub-basin’s Binational Community Committee; and the promotion of EbA as an effective response to climate change.