Climate change multiplies the complexities and intensity of water-related development challenges that countries have beeetnbsp; addressing for decades through national effort and transboundary cooperation. As pressure on water resources increases with climate change, current systems to manage these resources will no longer suf-fice. Populations have to rely more on water infrastruc-ture and water management to meet their needs andetnbsp; provideetnbsp; securityetnbsp; against the increasingetnbsp; occurrenceetnbsp; of extreme and variable hydrological events, such as droughts andetnbsp; floods. Givenetnbsp; hydrologicaletnbsp; interlinkagesetnbsp; thatetnbsp; connectetnbsp; territories,etnbsp; transboundary riveretnbsp; and lakeetnbsp; basins offer a logical geographic scope for countries to advance common development goals and address water-related challenges.