Appropriate water supply in terms of quantity, quality and timing is a key strategy for reducing saffron yield gap. This plant has high water productivity and drought tolerance, so that, its rainfed production is common in areas like many parts of Europe. However, it must be irrigated to achieve satisfactory yield in dry regions such as Iran, but much less compared with conventional crops. This chapter initially introduces saffron crop coefficients, then explains the irrigation scheduling before corm lifting, after corm planting, in pre-flowering stage, during vegetative growth and summer. Factors affecting water requirement such as field age and climatic conditions with particular emphasis on climate change has also been reviewed. Irrigation methods, water quality, flooding stress and indigenous irrigation knowledge are the other topics in this chapter. Rainfed cultivation and beneficial water related approaches for saffron production such as application of soil conditioners and saffron production under controlled environments have also been discussed.