China is about to realize a dream of Communist leader Mao Zedong to redirect China's river flows to benefit Beijing and the dry north, but critics say the resources grab by the politically powerful capital will harm regional China.
The $62 billion South-North Water Transfer Project is one of the world's biggest infrastructure projects.
Starting in October, stage two will see a massive 9.5 billion cubic meters of water per year pumped through 1,500 kilometers (932 miles) of canals and pipes from the Danjiangkou reservoir in central Hubei province to the northern provinces of Henan and Hebei and to Beijing.
The water project will provide more than a third of Beijing's water supply.
Critics say the diversion of 3.8 million Olympic swimming pools of water a year will further damage China's threatened rivers, many of which have run dry, and may threaten future investment in regional China.
In February, Qiu Baoxing, the vice minister of housing and urban-rural development, said the water diversion project was unsustainable and that the capital would be better off relying on desalination technology and saving rain water.
"By transferring such a significant volume of water away from the Han River Basin, the project is depriving the area of the most basic input it will need to develop in the years and decades to come," said Britt Crow-Miller, a research assistant professor at Portland State University.
"China's current development model is very short sighted. It's about keeping things growing at all costs and deferring the consequences as far into the future as possible," said Crow-Miller, an expert on China's water policies.
The first eastern route of the South-North Water Transfer Project (SNWTP) opened last year, but by the time the water arrived in the city of Tianjin it was so polluted after crossing contaminated soil it was rendered useless.
Pollution of China's waterways, like air pollution in major cities, is a major environmental crisis born from the country's rapid economic growth. The government has estimated that more than 70 percent of the country's rivers and lakes are polluted - half of it so badly it contains water unfit for human touch.
Almost 60 percent of China's groundwater is also too polluted to use, a consequence of lax environmental regulation and illegal dumping of industrial waste.
Dry Norther's insatiable thirst
The Danjiangkou reservoir gets its water from the Han River, a tributary of the Yangtze River which feeds several major cities in central China such as Wuhan, an economic power house in Hubei province sporting a $144 billion GDP.
"There will obviously be significant negative impacts on local waterways from which water is channeled into Danjiangkou," said Scott Moore at Harvard University's Kennedy School of Government, citing less water for agricultural diversions, ecosystem use and aquifer replenishment.
Poor areas like the Ningxia region in northwestern China have previously seen their water share from the Yellow River cut by a quarter as ever-more water is directed toward Beijing and Tianjin with their booming populations, while little is being done to reduce their water demand.
But the new water supply will come as a huge relief for northern China, one of the driest regions in the world where water scarcity has been made even worse by widespread pollution of rivers, lakes and groundwater.
Despite the lack of water, the region's economy relies primarily on water-intensive manufacturing industries and coal-fired power, and it produces around a third of China's food.
The biggest share of the water will be used for agricultural irrigation in Henan, while the rest will be distributed as drinking water and for industrial use across the region.
"The middle route will improve supply and reduce pumping of groundwater. In some cities, water resources can now be reserved for agricultural use and environmental conservation," the State Council SNWTP Office said in an email to Reuters.
But the massive water diversion may still not be enough to quench the thirst of China's northern industries.
The State Council, China's cabinet, last year approved the Zhengzhou Airport Experimental Zone, an economic hub in the capital of Henan province, meant to drive growth in the province for decades ahead.
Local water officials say that even with the massive water diversion, the water available to the zone in 2020 will be less than half of what is needed, with potentially disastrous consequences for the local economy.