Electric power generation poses a high stress to the water supply in China. In this study, we quantified China's water consumption by electricity generation from 2015 to 2030 by considering different scenarios of electric power generation structure and water consumption intensity, and analyzed water consumption by different sources of electric power and its regional disparity. We found there is a significant difference in water consumption among the presented six scenarios with water consumption varying from 1.78 to 3.62 gigatonnes (Gt) in the year 2030. We also found that water consumption by coal-fired power decreases while water consumption by natural gas and nuclear power increases. Water consumption was and will still be concentrated in the three northern and coastal areas of China. However, the development of renewable power and adoption of water saving technology would contribute to water consumption reduction in these regions. We used a decomposition model for investigating the scale, structure and technology effects of electric power generation on water consumption, and found they present positive, negative and negative effects, respectively. The strongest factor in reducing water consumption is the technology effect, highlighting the importance of adopting water conserving cooling technology. Our findings yield important hints for China's water conserving policy making in renewable power development, cooling technology choices and siting decisions.