Growing integration is turning cities in the Pearl River Delta region into a mega urban cluster of a projected 100 million people. Hong Kong and Macau will one day be linked with the new special zones of Hengqin (Zhuhai), Qianhai (Shenzhen) and Nansha (Guangzhou) in a densely populated corridor - each area with its own political, social and legal systems.
How well will this hybrid model function? It may just be too big to be healthy.
As a powerhouse of the Chinese economy, the Pearl River Delta (minus Hong Kong and Macau) encompasses only 0.5 per cent of the nation's land area and only 4 per cent of the mainland population, according to the mainland's 2010 census. It accounted for 9.4 per cent of gross domestic product, 27.3 per cent of total exports, and 17.3 per cent of utilised foreign capital.
Although the region's contribution to the mainland economy has decreased in recent years, it still holds a significant position in the overall development of China.
To enhance the region's competitiveness, Beijing has gone all out to support Guangdong's initiative to create special zones and called for the participation of Hong Kong and Macau to speed up integrated development.
But megacities can be monsters that gobble up resources. In the past 30 years or so, such a monster has been growing in the region, which has been forced to feed ever more mouths (7.3 times the country's average population density) with meagre resources ( only 1 per cent of China's water and using 8 per cent of its energy consumption).
If this monster continues to grow, more energy and water will no doubt be needed.
Energy and water are deeply interlinked. According to the United States Environmental Protection Agency, "drinking water and waste water plants are typically the largest energy consumers of municipal governments, accounting for 30 to 40 per cent of total energy consumed. Energy as a percentage of operating costs for drinking water systems can also reach as high as 40 per cent and is expected to increase 20 per cent in the next 15 years due to population growth and tightening drinking water regulations."
Given the current scale of urbanisation and the waste water treatment situation in the Pearl River Delta region, it is likely that the future energy demands for water alone will increase greatly.
That's even before the likes of infrastructure projects, manufacturing and other pillar industries that are energy and/or water intensive are taken into account in the planning of the region. This monster is already too big to feed. If such plans go ahead, it will become too big to keep healthy.
Su Liu is manager and policy researcher of Greater China at Civic Exchange