China's quest for water security is more than just a construction project for Gu Zhaoqi - it is his life.
Professor Gu, a student and then teacher of hydraulic engineering at Tsinghua University since 1949, has dedicated his career to the challenge.
He was one of the pioneer engineers who helped build dams across the mainland, including Beijing's Minyu reservoir and the Three Gorges project.
Reflecting on the early days of his work, Professor Gu - now in his 70s - said: 'That was a difficult time for the nation. We were very poor.'
He is also one of the thousands who has laid the groundwork for the South-North Water Transfer scheme that will divert water from the south to the parched north, a project first proposed by Mao Zedong in 1952.
In the 1970s, the government invited Professor Gu to help design the middle section of the three-route canal system. This 1,267km route will move 9.5 billion cubic metres of water from Hubei's Danjiangkou dam to Beijing and Tianjin.