Water plays a critical role in sustaining human health, food security, energy production, and ecosystem services. Population growth, climate change, and socio-economic and land use developments increasingly threaten water quality and quantity. The success of water resources policy and management is dependent on the integrative understanding of coupled human environmental systems and a careful consideration of uncertainty. Only through such integrative understanding is it possible to generate practical, scientifically sound, and socially acceptable solutions that are sustainable. The careful consideration of the implication of uncertainty is necessary if solutions are to be not just acceptable and sustainable, but also robust over a wide range of plausible future developments. This session provides a forum for discussing the advances in water resources systems analysis, planning and management under uncertainty for informing the planning, policymaking, and management of water resources in a changing world.