Dirty water puts two billion at risk, says UN agency
The United Nations' environment agency has expressed concern over the depletion and increasing pollution of underground reservoirs on which two billion people depend for their drinking water and irrigation.india Updated: Jun 10, 2003 11:45 IST
The United Nations' environment agency has expressed concern over the depletion and increasing pollution of underground reservoirs on which two billion people depend for their drinking water and irrigation.
"Developed as well as Third World countries are equally affected by the problem of the diminishing ground water sources," the UN Environment Programme (UNEP) said in a new report launched on Wednesday to mark the World Environment Day.
"Natural underground reservoirs, upon which two billion people depend for drinking water and irrigation, are under increasing stress and strain," the report warned.
It painted a worrying picture of "this critical, hidden, natural resource," as growing and thirsty cities, industries and agriculture take their toll, citing cases from across the world to highlight the global threat.
"In Arizona in the United States, 400 million cubic metres of ground water is being removed annually, which is about double the amount being replaced by recharge from rainfall," the report said.
"Almost a fifth of the water in storage in the huge Ogalla/High Plains Aquifer of the Midwest of the United States has been removed and the water table there has fallen in recent decades by, on average, three metres and up to 30 metres in some places," it said.
In Mexico, the number of aquifers considered over-exploited jumped from 32 in 1975 to nearly 130 by the 1990s, while in Spain, more than half of the nearly 100 aquifers are over-exploited, said the report, titled: "Groundwater and its Susceptibility to Degradation: A global Assessment of the Problem and Options for Management."
"In the important Segura River Basin of eastern Spain, the ratio of ground water storage depletion to available renewable water resources has increased from less than 20 percent in the mid-1980s to 130 percent by 1995." it said
"Ironically, some cities in very dry and arid regions like the Arabian Gulf are suffering a form of flooding, known as waterlogging, because of heavy dependence on desalinated water from the coast, which is leaking and becoming trapped in the ground," the report said.
"A typical Arabian Gulf coast city may be losing as much as a third of its water supplies to leaky mains and even more from over-watering of parks and gardens," the report warned.
"This heavy reliance on treated sea-water is, in some cases, partly due to these cities having polluted their own underground waters making them unfit for human consumption," said the report, released Wednesday at the main Environment Day celebrations in Lebanon.
"We are here in Lebanon for World Environment Day, the first time the event has been held in the Arab world, where it will have particular resonance in a region where it is estimated that in some areas over 90 percent of the population could be suffering severe water stress by 2032," UNEP Executive Director Klaus Toepfer said.
Topefer said the past 50 years had been marked by dramatic increases in the use of groundwaters as populations have grown, demand for food has climbed and industrialization has expanded in the developed and into the developing world
"This report is both cause for hope and concern and shows that many underground supplies are proving quite resilient to chemical and other kinds of pollutants, because slow passage through the rocks above them helps reduce or even eliminate health-hazardous substances before they reach supplies," Toepfer said.
"However, they appear more vulnerable to neglect or over-use. If a lake, river or reservoir becomes depleted or dries up, the event is highly visible, there is public outcry and often action taken," he warned.
"I hope this report will serve as a wake-up call concerning the human, social and economic consequences of squandering our vital underground water supplies and, hopefully, its findings will ensure that underground water supplies are no longer 'out of sight and thus out of mind', but quite rightly conserved for current and future generations," he added.