Water is essential for life, for agriculture. The potential threats of water shortage or flooding projected from rapid climate change are very likely raising severe hydrological hazard in many parts of the world. The agricultural production is expected to be affected and so is food security. The impacts yielded from the scarcity of water are among the prospects of climate change need to be carefully deal with, and the related issues are not simply agriculture-oriented but to all aspects of human living. We try to focus on rice production and use it as an example to review and discuss the techniques and strategies suitable for water-/irrigation-saving purpose in response to climate change. We do hope that the important points mentioned in the paper would help to reduce the increasing socio-economic and ecological disturbances and risks on Taiwan, though they are great challenges.