Newsweek International
January 30, 2002

Salt seeping up the Pearl River is threatening the delta. Environmentalists want local governments in the watershed to stop dam building, reforest the uplands and conserve water along the river’s 2,200-kilometre course.

Toxic spills have become all too common in China’s rivers – poisoning the Yellow (diesel), a tributary of the Yangtze (sulfuric acid) and, most famously, the Songhua (benzene), just in the last three months. Now southern China’s massive Pearl River faces a more innocuous contaminant: sea salt. This winter, saline flows have penetrated far into the booming Pearl River Delta, contaminating tap water used by millions of people in and around the former Portuguese enclave of Macao.

Chinese officials blame drought conditions and unusually high tides. But experts in Hong Kong and Macao also credit rampant industrialization and resource mismanagement in what’s become known as the world’s workshop. They say that factories and the migrant populations that fill them are drawing too much fresh water out of the river, causing sea water to flow further up. The salt can poison farmland, infiltrate aquifers and alter the ecosystem irreversibly. Indeed, even though the Pearl River delta is one of China’s wettest regions, cities and factories face rising costs as they source their water further upstream. The problem could well constrain growth in China’s most productive region.

In late December salt levels in water supplies for Macao and the nearby cities of Zhuhai and Zhongshan spiked; concentrations exceeded 600 milligrams per liter, double the World Health Organization’s maximum for safe drinking. Officials have instructed citizens to drink and cook with bottled water, and warned that the problem could persist until spring. Last week upriver provinces opened the floodgates on several dams to flush out the lower delta.

Part of the problem is indeed upstream, where deforestation has reduced the soil’s ability to retain moisture. Since less rain is absorbed during the wet season, less flows downstream during the dry season. One result: the boundary where fresh water meets ocean tides moves upstream. The booming economy downstream also plays a role. Population and industrial growth have been sucking up fresh water, leaving even less to fight back the salty tides. While Chinese authorities are gradually becoming more aware of environmental issues, they are less likely to shut down the seaboard’s humming factories. “Increased dam building, increased water extraction and changing land use all will effect the pattern of runoff,” says Hong Kong University biologist David Dudgeon. “Salinization will become a bigger problem.”

Environmentalists want local governments in the watershed to stop dam building, reforest the uplands and conserve water along the river’s 2,200-kilometer course. They also want to end riverbed dredging to gather sand and gravel for construction, which deepens channels and intensifies salinization. Beijing is more likely to back a different course: building more dams to store summer rains and shipping that water by pipeline to the coast. That’s a politically palatable solution but a bad trade-off: experts say such projects will only compound the problem.