Freshwater allocation has been a significant issue in New Zealand, particularly in the rich agricultural regions of the South Island, for over a decade, and has given rise to significant litigation before the superior courts.¹ For example, in the Canterbury region there is competition for access to freshwater between agriculture and hydro electricity generation, and between agricultural users in terms of their needs for irrigation. In part, this results from land use change, with the conversion of sheep and beef farms to dairy farms. During the period 2002–2012 dairy farming increased by 28 per cent.²