Nearly half of the world's people will be living in areas of acute water shortage by 2030, the United Nations warned last week, and an estimated 1 billion people remain without access to safe drinking water and sanitation.
The world's population of 6.6 billion is forecast to rise by 2.5 billion by 2050. Most of the growth will be in developing countries, much of it in regions where water is already scarce.
As populations and living standards rise, a global water crisis looms unless countries take urgent action, the international body said.
"Water is not enough of a political issue," said Daniel Zimmer, associate general of the World Water Council, one of the organizations behind the World Water Forum.
"One of the targets is to make politicians understand that water should be higher up on their domestic agenda and care that it is a necessity for the welfare, stability and health of their populations."
Because of the lack of political attention, hundreds of millions of people remain trapped in poverty and ill health and exposed to the risk of water-related disasters, the U.N. warns.
U.N. Secretary-General Ban Ki-moon has said water scarcity is a "potent fuel for wars and conflict."
Water shortages have been named as a major underlying cause of the conflict in Darfur in western Sudan. Water is also a major issue between Israel and its Arab neighbors, and the states of Central Asia, one of the world's driest places, where thirsty crops such as cotton and grain remain the main source of livelihood.
Tajikistan has asked World Water Forum organizers to mediate in its dispute with Kyrgyzstan over water during the conference, World Water Forum Vice Secretary Ahmet Mete Saatci told Reuters.
Other subjects on the agenda for the talks from March 16-22 will be how to avert catastrophic floods and droughts as climate patterns change, and how the global financial crisis threatens to hit large-scale water infrastructure projects within the next several years.
The heads of state, environment and development ministers, scientists and development organizations hope to draw up a list of recommendations to help safeguard water resources and to share experiences where projects have been successful.
Among the heads of states attending the conference is Iraq's President Jalal Talabani.
Does the US have a comprehensive water policy?