The John Dalton Medal is presented to Jeffrey J. McDonnell for his distinguished contributions to experimental hydrology. The Dalton Medal Lecture will be introduced by a citation delivered by Hubert Savenije.

Jeff McDonnell presently holds the Richardson Chair in Watershed Science at Oregon State. He has an international reputation as an exceptional scientist, a charismatic teacher and an influential world leader in watershed hydrology, achieved through groundbreaking research experimental rainfall-runoff studies, isotope hydrology, hydro-biogeochemistry, hydrologic theory development, and watershed modelling. His research has focused on understanding basic hydrologic processes in terms of where water goes when it rains, the multiplicity of pathways that it follows on its way to the stream, and the distribution of residence times of that water along these pathways. While basic, these questions have served to define new conceptualisations of runoff behaviour based on the field research that he has carried out in watersheds around the world, especially in Canada, USA and New Zealand.