UNITED NATIONS - As more than 20,000 people meet in Istanbul for a major week-long conference on future management of the world's water supplies, women's groups are working to ensure that policy decisions about this critical natural resource take their concerns into account.

Women carry buckets of water in Bissau March 6, 2009. (REUTERS/Luc Gnago/GUINEA-BISSAU) About a billion people currently lack safe drinking water, and another two and a half billion have no access to sanitation.

Experts note that women and girls carry the burden of the water crisis since they bear more household responsibilities, such as hygiene, cooking, gathering water, and taking care of children and the sick.

Those tasks expose them to many risks, like contamination by water-related diseases and violence in conflict zones, and often prevent them from going to school or having a job.

According to the U.N. children's agency UNICEF, in developing countries women and girls walk an average of six kilometers a day carrying 20 liters of water.

"When we use water faster than it is naturally recharged, it is not sustainable," said Peter Gleick, director of the Pacific Institute, a nonpartisan research organization based in California.

Unlike oil, water is not a non-renewable resource. However, it is limited by its location and flow. Many experts say the world has now reached "peak water" - meaning that available resources are eclipsed by massive, and growing, demand.

"In a few years, [the problem] will be exacerbated by climate change," Tracy Rackez, an expert on environmental issues at the U.N. Development Fund for Women (UNIFEM), told IPS. "We need to find ways to make women and men have equal access to clean water."

She added that women also tend to be more responsible for growing food for household consumption and local markets - in some areas they are 70 percent of small farmers - and play a critical role in improving water-use efficiency, especially with drip irrigation and rain catches.

"There are a lot of innovations and numerous tools that have to be in the hands of women to help them to be more efficient," she said.

In addition to the waste and inefficiency of current water use models - particularly in the agricultural sector, where 40 percent of production comes from non-renewable resources - they also have dramatic environmental impacts.

For example, rapid population growth and industrialization in China has caused 80 percent of wetland plants to dry up and driven species to extinction. Chinese water quality has severely decreased because of industrial waste and untreated contaminated sewage aquifers.

This excessive use of water also has economic repercussions - companies and industries have had to cancel projects and close ventures because they could not find the water quality that they needed.

"For developing countries, it is extremely important that they look forward in their economic and social development to the recognition of what level of renewable water resources they have available within the national boundaries and that they seek to optimize their use in all sectors - and in particular in agriculture," Andrew Hudson, head of the Water Governance Program at the United Nations Development Program (UNDP), told IPS.

Expanding on existing solutions like drip irrigation and recycling water requires advanced technology, smart economics and better governance in water management. "There is no doubt we can grow more food with less water," Gleick said.

In fact, water efficiency programs could also cut greenhouse gas emissions by saving energy, as 80 percent of the world's water is used to produce food and industrial products.

However, few governments prioritize water and even less sanitation, so these issues get neglected, Hudson said.

At the same time, access to clean water is internationally recognised as a human right, implying a responsibility for governments to provide it to the one out of six people lacking access.

The water industry rakes in an average of 400 billion dollars a year in services, equipment and selling water itself.

Meanwhile, an additional 11.3 billion dollars each year could help to meet the Millennium Development Goal target of reducing by half the estimated 2.6 billion people living without adequate water and sanitation, according to UNICEF.

"Most countries have to recognize that provision of water supplies and sanitation services to people is the most important driver for long-term economic growth," said Hudson.

In Istanbul, groups like the Gender and Water Alliance (GWA), Turkish Women's Water Platform and Women for Water Partnership (WfWP) have been organizing sessions to enhance the participation and visibility of female community leaders, experts and policy makers.

Anta Seck, a water engineer and director of water resource management and planning in Senegal, noted that "it is important for men to open up this world to women."

"Women are responsible for the usage of water, therefore, it is important to develop the capacity of women in the management of water - and that includes getting advanced degrees," she said at the conference.