"Behind the world food crisis is a global freshwater crisis, expected to rapidly worsen as climate change impacts intensify," Leape said. "Irrigation-fed agriculture provides 45 percent of the world's food supplies, and without it, we could not feed our planet's population of six billion people."

Leape warns that many of the world's irrigation areas are highly stressed and drawing more water than rivers and groundwater reserves can sustain, especially in view of climate change. At the same time, he said, freshwater food reserves are declining in the face of the quickening pace of dam construction and unsustainable water extractions from rivers.

The World Water Week fountain in Stockholm (Photo by Alex de Sousa)

At a time when billions of people live without access to safe drinking water or suffer ill health due to poor sanitation, when food producers battle biofuel producers for land and water resources, and when global climate change is altering the overall water balance, 2,500 water experts are gathered this week at the Stockholm International Fairs and Congress Center to craft solutions to these problems.

World Water Week is an annual event co-ordinated by the Stockholm International Water Institute. This year's conference has the overall theme of “Progress and Prospects on Water: For A Clean and Healthy World with Special Focus on Sanitation" in keeping with the UN declaration of 2008 as the International Year of Sanitation.

Prince Willem-Alexander of the Netherlands had good news for the delegates in his opening speech today.

The Prince of Orange, who chairs the UN Secretary General's Advisory Board on Water and Sanitation during this special year, announced, "The number of people living without a supply of improved drinking water has now dropped well below one billion!"

"More than half the global population now have water piped to their homes and the number of people using unimproved water supplies continues to decline," he said, praising the delegates for this accomplishment.

This year, the prince said, progress towards adequate sanitation has begun on international, regional, national and local levels. "The regional sanitation conferences for example, such as LatinoSan, AfricaSan, EaSan and SacoSan, produced unprecedented declarations that provide a strong foundation for developing the water and sanitation sector in these regions," he said.

In June, the African Union Summit on Water and Sanitation in Sharm El Sheikh, attended by 52 heads of state and government, unanimously adopted a declaration on water and sanitation that shows that African leaders are giving top priority to water and sanitation, the prince said. "It also provides a solid basis for further developing the sector in Africa. I personally consider this result to be an enormous leap forward."

Children in Sudan enjoy a clean drink of water. (Photo courtesy UNICEF)

But Prince Willem said much more must be done to meet the UN's Millenium Development Goal to halve the proportion of the population without sustainable access to safe drinking water and basic sanitation by 2015 from the year 2000 baseline.

Citing a report by the World Health Organization and UNICEF, he said, "The report's worrying conclusion is that, at the current rate, the world will miss its MDG sanitation target by more than 700 million people. If we are to reach the target we now need to provide at least 173 million people per year with access to improved sanitation."

A consistent supporter of World Water Week, the prince told the delegates he finds it "unthinkable" to let a year go by without visiting the conference, although he is supposed to be in Beijing observing the Olympic Games in his capacity as a member of the International Organizing Committee.

"I see similarities between these athletes and yourselves," said the prince. "You show the same commitment and willpower. And the Olympic Dream is also your dream: to strive for a bright future of mankind. ‘One world, one dream.' A world in which everyone can lead a healthy life in dignity. A world that offers the chance of personal development for all. This is our common dream."

The delegates will need all the inspiration they can get to overcome the problems they face.

As developing countries confront the first global food crisis since the 1970s as well as unprecedented water scarcity, a new 53 city survey presented at the conference by the International Water Management Institute indicates that 80 percent of those studied are using untreated or partially treated wastewater for agriculture.

Latrine over a waterway in Haiti (Photo by Remi Kaupp)

In over 70 percent of the cities studied, more than half of urban agricultural land is irrigated with wastewater that is either raw or diluted in streams.

"Irrigating with wastewater isn't a rare practice limited to a few of the poorest countries," said IWMI researcher Liqa Raschid-Sally and lead author of a report on the survey results. "It's a widespread phenomenon, occurring on 20 million hectares across the developing world, especially in Asian countries, like China, India and Vietnam, but also around nearly every city of sub-Saharan Africa and in many Latin American cities as well."

Wastewater is most commonly used to produce vegetables and cereals, especially rice, according to this and other IWMI reports, raising concerns about health risks for consumers, particularly when they eat uncooked vegetables.

In Accra, Ghana's capital city, for instance, an estimated one-tenth of the city's two million inhabitants daily purchase vegetables produced on just 100 hectares of urban agricultural land irrigated with wastewater, says the IWMI report. "That gives you an idea," said Raschid-Sally, "of the large potential of wastewater agriculture for both helping and hurting great numbers of urban consumers."

"And it isn't just affluent consumers of exotic vegetables whose welfare is at stake," she added. "Poor consumers of inexpensive street food also depend on urban agriculture."

Consumers across the 53 cities said they would prefer to avoid wastewater produce. But most of the time, they have no way of knowing the origin of the products they buy. Farmers, too, are aware that irrigating with wastewater may pose health risks both for themselves and the consumers of their produce, but they have little choice, since safe groundwater is seldom an accessible alternative, according to the IWMI report.

Few developing countries have official, enforceable guidelines for the use of wastewater in agriculture. As a result, though the practice may be theoretically forbidden or controlled, it is in fact "unofficially tolerated," the IWMI found.

The report highlights indigenous practices that can reduce the health risks from wastewater agriculture. In Indonesia, Nepal, Ghana and Vietnam, for example, farmers store wastewater in ponds to allow suspended solids to settle out.

The dried up bed of Kenya's Voi River (Photo credit unknown)

Countries lacking the means for adequate wastewater treatment can still reduce health risks through low-cost interventions, such as the use of drip irrigation and washing of fresh produce in clean water.

Of the world's total water resources, 97.5 percent is salty and of the remaining but mainly frozen freshwater, only one percent is available for human use, said Leape, the WWF chief.

"Even this tiny proportion, however, would be enough for humans to live on Earth if the water cycle was properly functioning and if we managed our water use wisely," he said.

But Leape warned the conference delegates that the world is a long way from being ready for a worsening water crisis in part because of climate change and lack of an ecosystem approach to freshwater management.

"Water management for human needs alone is damaging the natural systems we all depend on," Leape said. "No management is even worse."

"We are also concerned that the world continues to mainly discuss adaption to climate change rather than doing it," Leape said. "We have been doing it, all over the world, and we have found that that improving the health of freshwater ecosystems now makes a great contribution to improving their resilience to climate impacts in the future."

www.ens-newswire.com/ens/aug2008/2008-08-18-01.asp