WWF study on escalating water problems for world’s megacities

August 23rd, 2011 by WWF

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A WWF report has shown that the likelihood of water shortages in global megacities (defined by UN Habitat as cities with more than 10 million inhabitants) is set to escalate, with 70% of the world’s population projected to be living in urban areas by 2050.

Published during World Water Week, the report ‘Big Cities, Big Water, Big Challenges’ warns of severe water shortages worldwide by the middle of the century.

The report illustrates the already serious implications of poor water management in megacities around the world, and focuses on five case studies:

• Mexico City, Mexico – over-exploitation of aquifers has contributed to the continued subsidence within the city (5-40 cm per year), increasing the chance of catastrophic flooding
• Buenos Aires, Argentina – the Riachuelo, one of the most polluted waters in the world, contains levels of lead, zinc and chrome 50 times higher than the legal limit in Argentina
• Nairobi, Kenya – sixty percent of the inhabitants live in informal settlements with inadequate access to quality water and are forced to buy highly-priced water at kiosks
• Karachi, Pakistan – eighty percent of untreated wastewater is discharged into the Arabian Sea and around 30,000 people, mostly children, die each year in the city due to consumption of contaminated water
• Kolkata, India – the city is struggling to contend with faecal contamination of municipal water and arsenic pollution of groundwater
• Shanghai, China – the city already experiences high water stress due to the rising demand of 23 million inhabitants

Martin Geiger, Head of Freshwater, WWF Germany said: “It’s vital for cities to protect and restore ecosystems that are important water sources. As well as reducing unnecessary consumption, successful water and wastewater management is also essential to support agriculture. Cities must begin conducting vulnerability tests and ensuring government and stakeholder involvement to assess risk and prepare for the increased populations we are expecting in the future”.

The report also highlights the importance of calculating water footprints, which measure the total volume of water used to produce goods and services and the effects of pollution from waste water. Water footprints can incorporate a more holistic assessment of the demand placed on water resources by humans, to calculate availability of water and help supply more water to megacities and reduce impact on freshwater environments.