CHENZHOU, Sept. 8 (Xinhua) -- Dongjiang Lake is a renowned scenic area and a vital source of drinking water nestled in Chenzhou City, central China's Hunan Province. Beyond supplying high-quality water to the region, the lake's cold water serves as a "natural air conditioner" for a major big data center. How much can a drop of water do? Join Xinhua correspondent Fu Tian to follow an extraordinary journey of the Dongjiang Lake water.