On behalf of the Organising committee, it is my great pleasure to invite you to Dublin from the 24th to the 25th April, 2014 for the inaugural 2014 Dooge-Nash International Symposium. The Symposium will be held in Dublin Castle and will honour the memory of two Irish Hydrologists, Professor Jim Dooge and Professor Eamon Nash in establishing, internationally, the key role of hydrology in many critical, global issues relating to environment, ethics, food, energy and the developing world in addition to their seminal roles in the emergence and development of Systems Hydrology. In keeping with their philosophy and attitudes of both men, we have chosen as our symposium theme the Grand Challenges facing hydrology in the 21st century. Led by selected keynote speakers, we hope to engender a penetrating discussion of the key future challenges for hydrologists. We expect the contributions and outcomes will be published in a number of special issues of selected journals. The 2014 Dooge Nash International Symposium will bring together a mix of national and international delegates from government, research and education with interests in hydrological science across a broad range of disciplines. Above all, the Symposium will be a great opportunity to meet, greet and talk hydrology with new and old colleagues from around the world. We invite the hydrologists of the present, and especially former colleagues and students of Jim and Eamonn, to come to Dublin, for the 24th and 25th of April 2014, to consider and contribute to the hydrology of the future in the context of a sustainable and just planet.