Paper short abstract:

When vitis vinifera is grown outside its indigenous regions, irrigation is necessary. 99% of the water used in wine-making is for irrigation. In fact, irrigation is viticulture's number one adaptation ally, whilst it is mitigation's number one foe.

Paper long abstract:

Climatologists love wine. The vitis vinifera is the crop most susceptible to changes in climate, and its harvest conditions and migration patterns serve as models for future climate scenarios. It is interesting then, that this thirsty $30 billion international industry and its water emergency has not come into sufficient focus. Cultural traditions and consumer attachment to this luxury commodity has protected it from scrutiny: wine grapes rarely feature in discussions of water competition: when in fact, there are regions (ex. South Australia) where local water licenses are allocated to wineries rather than to agricultural crops and livestock.

The Water Footprint Network reports that it takes 29 gallons (131 litres) of water for a glass of wine (comprising blue, green and grey). This calculation would have taken into account the type and frequency of irrigation, planting density, type of rootstock, trellising style, soil properties, varietal and a vineyard's temperatures, wind and sun exposure. With more erratic harvest conditions existing within increasing temperatures (weather vs climate), the majority of the world's viticulturists are under threat from drought. Water prices are crippling and over-irrigation leads to soils too-heavily salinated to sustain any further agriculture.

This paper is concerned with investigating the comparative use of blue water (irrigation) amongst the principal wine regions: techniques employed; type of water used (recycled/fresh); resulting yield ratios (on average, irrigated yields are larger than rain-fed yields which can skewer the footprint calculation); and examines the industry's adaption methods in regard to irrigation.