A seven-day focus on the world's water crunch wound up in Istanbul on Sunday with a pledge by more than 100 countries to strive for clean water and sanitation for billions in need and fight drought and flood. But some countries criticized the cornerstone outcome of the fifth World Water Forum as flawed while activists dismissed the event itself as a "trade show." The declaration, coinciding with World Water Day, was issued at the end of a three-day ministerial meeting, climaxing the biggest-ever conference on the planet's crisis of freshwater. "The world is facing rapid and unprecedented global changes, including population growth, migration, urbanization, climate change, desertification, drought, degradation and land use, economic and diet changes," the statement said. It set out a roster of non-binding recommendations, including greater cooperation to ease disputes over water, measures to address floods and water scarcity, better management of resources and curbing pollution of rivers, lakes and aquifers. Access to water 'a basic human right'? Some countries tried to beef up the statement so that it recognized access to safe drinking water and sanitation as "a basic human right," rather than a "basic human need", which was the final text. They were blocked by Brazil, Egypt and the United States, delegates said. Around 20 dissenting countries signed on to a separate statement to spell out their position after the conference's close. They included Spain, Switzerland, Bangladesh and South Africa. Severe water stress (Photo: AP) The textual difference, which has political and legal ramifications, is being debated under the UN Convention on Human Rights. Numerous countries, led by Latin America, have already enshrined access to water as a right in their constitution. The World Water Forum is held every three years, and has gained in importance as a meeting place for debating the globe's amplifying problems of freshwater. At least 25,000 policymakers, water specialists and grassroots workers took part in this year's event, a record attendance. Campaigners representing the rural poor, the environment and organized labor on Saturday attacked the Forum as a vehicle for water privatization and called for it to be placed under the UN flag. "We demand that the allocation of water be decided in an open, transparent and democratic forum rather than in a trade show for the world's large corporations," said Maude Barlow, senior advisor to the president of the UN General Assembly. Privatization a thorny issue The Forum is staged by the World Water Council, a French-based organization whose funding comes in large part from the water industry. Providing access to drinking water and sewerage, conserving resources and building reservoirs and dikes to cope with water stress and water excess would cost rich countries alone around 200 billion dollars per year, according to estimates. "Mobilizing the resources ... is likely to be one of the greatest challenges we face," said US delegate Alonzo Fulgham. The ministers said they would "promote effective use of financial resources from all sources" but did not state a preference for whether water should be in public or private hands. This is a thorny issue, because campaign groups say utilities that are in private hands ramp up tariffs, hitting the poor especially. However, the ministers said they "acknowledge" that the costs of recovering water investment had to be "fair, equitable and sustainable." Need for water rapidly growing Around 880 million people do not have access to decent sources of drinking water, while 2.5 billion people do not have access to proper sanitation, the Organization for Economic Cooperation and Development (OECD) said in a report on Tuesday. By 2030, the number of people living under severe water stress is expected to rise to 3.9 billion, a tally that does not include the impacts of global warming, according to the OECD. The world's current population of more than 6.5 billion is growing at the rate of 80 million a year. By 2050, there is expected to be nine billion people. Feeding them -- and growing crops for biofuels -- will spur even greater demands from agriculture, which already takes up 70% of available freshwater.