They were talking about transferring 60 billion cu/m of water annually and creating 200000 square kilometers of new arable land from desert and steppes, all flatlands. This while restoring the north china plain aquifers and completely reversing desertification all along Gansu, Shannxi, Shanxi, Hebei. There was talk of having the water transfer approach 90-100 billion cu/m but they decided to limit it to 60 billion cu/m in deference to the downstream riparian countries. It would also transform the ENTIRE southern part of the Tarim Basin from a huge desert into a gigantic oasis that would allow mostly untappable resources to now economically extractable resources. We're talking about all the oil, gas, minerals, agriculture, real estate development, etc.
Plus, the regional climatic changes this would cause would increase rainfall and drop temperatures all along China's northern and western peripheries. China's existing farmlands would also benefit as the temperate rain zone moved northward. We already have examples of this from the Loess Plateau reforestation project which resulted in increased rainfall to the extent that the entire ecosystem of Shanxi was transformed from barren wastes to the green fertile land it is today, not completely but largely because of increased rainfall.
Extensive land sale costs alone would pay the entire cost of the project. The multi-trillion cost would be easily recouped in under 10 years EASILY. We're talking about geoengineering almost a quarter of China's land area where a lot of the absolute poor used to live specifically because the environment made them that poor.
Those reports overstate the potential water problem. Glacier melt regulates river flow during the dry season through meltwater. Whether China went ahead or not with this project, that will eventually happen anyways someday. You're looking at this as if it would have zero effect. What would actually happen is, during the monsoon season, tens of billions of tonnes of water would be filling up China's underground aquifers, dams and reservoirs and supply the needed water during the dry season. The same would be happening in other countries but probably much less effectively. Imo, this project would be 50 times more beneficial than the 3 gorges dam, but way more risky because any single interruption along the water transfer in the southwest through the earthquake prone mountains would disrupt the water flow and force them to divert water back to the source rivers. In other words, the ongoing maintenance of this could be non-stop which means the water supply could potentially be unstable. Is it worth it anyways, Absolutely. We're talking about a fundamental strategic change to the land of China that would result in increased self-reliance of food, energy, raw materials, water, livable land, you name it. So, is it going to happen? From what we know, there is no official government interest in it. Most of the discussion about it has actually come from Indian anti-China media who reported it as China's plan to attack India's Brahmaputra River.