This document presents a methodological guide for the use of a water planning and water distribution tool (WEAP), which can be applied at different scales, from small to large catchment basins, at a local or regional area. WEAP was implemented in six strategic basins of Ecuador, which were selected for "The Adaptation to Climate Change through an Effective Water Governance" project with the objective to increase resilience in response to climate change risks in the water resources management at national and local level.