Mexico City Faces Water Crisis as Demand Spirals
Author: Tim Gaynor
"We've been waiting for mains water for 10 years now, and we are getting tired," she said as she stoops over a water barrel in Mexico City's Lomas de San Juan Ixhuatepec suburb. "It's high time it was all sorted out."
The mother of three is among more than a million residents of the Mexican capital and surrounding area who depend on a roving fleet of water trucks, or "pipas," to meet their basic need for water as the capital faces a deepening crisis.
Once a thriving Aztec citadel set on a broad highland lake, Latin America's largest city is threatened with outages, rationing and an angry population as the water needs of its growing population outstrip hard-squeezed supplies.
The city is sinking into the soft, drained lake bed as its aquifers collapse. It has a hemorrhaging distribution network and is forced to buy around a third of its raw water from neighboring river basins to supplement the ever-expanding metropolitan area's needs.
"During the last eight years, water supplies have remained stable while the population has grown, leaving us with a deficit," said Alejandro Martinez, operations director of Mexico City's water board.
"If we don't look after our water, we could have a crisis of supply in the short term ... which would make it necessary to ration water," he said.
While the population of Mexico City proper has remained static in recent years, the number of people in the greater metropolitan area has swollen to almost 20 million people, as some 1,100 rural migrants pour into the conurbation each day in search of a better life.
"It's not possible to separate the metropolitan area's demand for water from that of the city itself because people travel in from the surrounding area each day to work and study," said sociologist Carlos Welte of the National Autonomous University.
With a raging thirst for 7,250 gallons of water a second - equivalent to almost one Olympic-size swimming pool every minute - the city's sandy clay aquifers are pushed beyond their limit.
Sucking up water from 620 deep wells at an energy cost greater than the annual consumption of Haiti, parts of the city have plunged 30 feet (9 m) into the subsoil since the 1900s.
Subsidence has thrown historical monuments out of true - including the yellow-domed Basilica de Guadalupe shrine and the colonial Metropolitan Cathedral.
"We have subsidence in the South of the city of up to 30 centimeters (1 foot) each year, and it has affected (sites) like the cathedral," Martinez said.
SAVINGS OFFSET LOSSES
Environmentalists and architects are experimenting with ways of using rain water for routine tasks such as flushing toilets and bathing.
"The day will come when the water that we draw from the subsoil will be insufficient," said Martinez. "We have to look for alternatives and new technologies to provide a solution."
Ilan Adler, regional director of the International Renewable Resources Institute, has pioneered several techniques at the city's Alliant International University, including harvesting rain water on the rooftop.
Authorities have reported clashes between neighbors in the city's water-starved districts as people steal water from each other.
"If Mexico City doesn't start catching and recycling water, it will face social unrest. It's not about whether or not you have a car or a TV, it's much more serious than that: It's about survival," Adler said.
Ensuring water supplies depends on recovering water lost to leaks - which currently amounts to 27 percent of the total - together with recycling and water-saving programs.
The authority, which has laid over 800 miles of new pipes in the past five years, believes it can save 1,100 gallons of water a second by plugging leaks.
Programs to recycle waste water for industrial use and agricultural irrigation would create further savings, currently projected at about 880 gallons per second.
But the biggest challenge lies in