Each of these soil types contributes to the rich diversity of wine produced by the winemakers of the wine region. Overall the soils have one common trait; they are free draining which means they hold very little water. This is, in fact, an advantage, as it allows the accurate control of moisture to the vines through the use of state-of-the-art drip irrigation. Because of reliable winter rain, irrigation can be kept to low levels and manipulated to achieve the production of superior fruit.