Yield, grape composition and wine sensory attributes tightly depend on vine water status. Hence, the measurement of vine water uptake is important for research purposes as well as for practical vineyard management. Many techniques have been developed over the past decades. Among them, three are of particular interest, because they are easy to implement, robust and because their utilization is complementary: stem water potential , carbon isotope discrimination measured on grape sugar and water balance. The present chapter describes and compares these three methods . It also indicates in which situation each of them will be most useful for researchers and vineyard managers.