The PI proposes to convene a community-wide workshop on water as a complex environmental system entitled: Water: Challenges at the Intersection of Human and Natural Systems. They hope to stimulate community interest and focus the direction of future research which the Foundation is currently not addressing in its funding portfolio. Some examples of high priority topics include: river systems as a continuum; processes at interfaces; intensively managed or engineered systems; large-scale processes; biological mediation and processing; functions in aqueous solution; decision-making and processing information, uncertainty; cyber-infrastructure; modeling for dynamical complex systems; and innovative technologies for human utilization. The aim would be to produce recommendations that could then be used to articulate the community's vision for the next generation of research which might be reviewed by the AC-ERE in its advisory process.