Zhang Jiyao, former Director of the South-to-North Water Division Project Commission Office, stated in an interview with China.org.cn that constructing a western route of the world's largest water system is very much possible and it is only a matter of time.

"Personally, I think it is very necessary and likely to start building a western route," said Zhang. "It is just a question of 'when' construction should begin."

"Six western drought-prone provinces have urged the start of a western route construction," he said. "The central and eastern lines of the project are still not sufficient to meet the water shortfall."

Commenting the necessity of the western route, Zhang said: "We should figure out a way to increase water supply and address the issue, so the construction of a western route is a solution."

Yet, there is no timetable for the construction of the route and the feasibility work is still in progress.

The western route, also known as the Big Western Line, is to transport water from the headwaters of the Yangtze River into the headwaters of the Yellow River.

According to Zhang, the Yellow River Conservation Commission is responsible for conducting research on the feasibility of a western route construction and is now working on proposals to hand in to the government.

The South-to-North Water Division Project, which has been controversial for its considerable price tag and highly-debated consequences, started construction on its first two routes --the eastern and central water division tunnels-- in 2002 and 2003 respectively, whereas the western route is still on the drawing board.