The Congress theme “Balance and Uncertainty: Water in a Changing World” focuses on the central roles of hydraulic engineering, hydrology and water resources in our changing world, and how these roles link to the broader issues. A balance is continually being sought between competing values in water engineering, including the environment, the economy, tourism, social and indigenous values, health aspects, aesthetics and the needs of current and future generations. Careful management and innovative solutions are required to balance these values and solutions must be able to deal with the uncertainty in the natural world as well as the changing human world.