Despite the years of planning and complexity of the project, its capacity, at 16bn cubic metres per year, is about half what European planners had hoped.
In America, average PM2.5 levels in populated areas are around twice the World Health Organisation recommended maximum of five micrograms per cubic metre.
Eventually the South North project is intended to deliver 45 billion cubic metres of water a year and to cost a total of 486 billion yuan( $79.4 billion).
With the site cleared, explosives were used to break up tough ground and excavate the venue's bowl — an exercise that saw over 685,000 cubic metres of earth removed.
In Boston, for example, north-easterlies blowing into the city from industrial areas bring air carrying around five micrograms per cubic metre more PM2.5 than westerlies from upstate Massachusetts.