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The freshwater environment is facing unprecedented pressures. Unsustainable use of surface and groundwater is ubiquitous, and degradation of water quality. Flood damage is increasing, and droughts have global consequences as well as local impacts. These current pressures are set in the context of rapid environmental change, socioeconomic development and population growth. In the face of these critical societal challenges, what are the needs and role for water science?

Clearly there is an increasing need for deep understanding of aquatic and terrestrial environments and their interactions with the climate system, and further, analysis of their vulnerabilities to environmental and societal change. This requires recognising the human dimensions of water science; the water environment in the 21st century is a complex human-natural system. And for the science community to be useful, it must address the key issues of societal relevance, provide useful knowledge and relevant tools and develop effective communication with the user community. Stakeholder engagement is an imperative, not an option, if science is to play a meaningful role in shaping water futures.

How can this be achieved? The talk seeks to demonstrate, using the World Climate Research Program concept of Regional Hydroclimate Projects, that large-scale catchment-based observatories can provide the data support and management focus for new trans-disciplinary science, the development of new understanding of environmental change across multiple scales, its translation into user-focussed decision support tools to address key societal issues, and stakeholder engagement at multiple levels. Now is the time for the global community to address these challenges through an integrated effort at large basin scale.
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