The purpose of the Symposium is to discuss ways in which hydrologists can contribute most effectively to the planning and management of freshwater projects, including the efficient operation of existing systems faced with new socio-political situations. It will also address how water resource managers can capitalize on the hydrological expertise available to them. At the Symposium, hydrologists and water resource managers are invited to discuss these topics, taking into account the need to include more environmental, social and economic aspects in the planning and management of such projects, while keeping in mind the sustainability of water resource systems and related projects. As hydraulic and water management projects can have negative impacts on the environment, those with expertise in environmental matters will be particularly welcome.