In line with the SDGs, this article assesses the water consumption of hydropower in Brazil, therefore addressing SDGs 6 and 7. Severe droughts in 2014-2015 unveiled water availability issues affecting electricity, making the relationship between water and energy more prominent, and highlighting a lack of methodological approaches and well-defined metrics. It is argued that the resource nexus is a concept that could greatly assist in assessing water and energy issues, since it integrates important aspects of sustainable development and helps in the identification of critical tensions between resources, while highlighting possible synergies. Furthermore, the importance of evaporation and measuring water consumption for hydropower is presented, since for the case of Brazil, for a 1°C future increase in temperature, evaporation will increase by about 90mm. This will create serious water availability issues for the country, which creates questions about future hydropower plans. It is argued that future hydroelectricity plans should undergo stricter water impact assessment. Specifically for Brazil, an integrated resource policy with more resilient hydropower, complemented by upscaling wind and solar, is suggested as a sustainable pathway. Finally, for the SDGs to have an actual chance of being achieved, some serious methodological gaps need to be addressed.