A United Nations report released Wednesday on the state of the world's fresh water warns that decreasing water supplies could lead to epidemics and international conflict.

The World Water Development Report is the UN's first global evaluation of water resources and compares countries in terms of water quality and availability.

WATER STATISTICS
* By 2050, per capita water supply is predicted to fall, leaving anywhere from 2 billion to 7 billion people with water scarcity * 270,000 people per day between now and 2015 will need clean glasses of waterSources: Gordon Young, World Water Development Report

The availability of clean water varies greatly around the world, from more than 500,000 cubic metres per person in French Guiana and Iceland, to less than 100 cubic metres in Kuwait and the Gaza Strip.

Canada is in the middle of that range, but is second to Finland for the world's highest water quality.

The report said those numbers are changing, and clean water is becoming more scarce.

Gordon Young, a geographer at Wilfrid Laurier University in Waterloo, Ont., compiled the report released Wednesday in Tokyo.

"If human beings dam the rivers, or pollute the water supply, dumping wastes into rivers and lakes and groundwater reservoirs, then the natural environment suffers," he said.

According to the report, one in three people do not have enough water for proper hygiene and one in five do not have enough to drink.

Over the next 20 years, the average global supply of water per person is expected to drop by one-third. By the middle of the 21st century, 2 billion to 7 billion people will be severely short of water.

Young said that drop will only make health problems worse in certain parts of the world. Already, 6,000 people die from diarrhea every day.

He said Canadians shouldn't let their abundant supply of clean water lull them into complacency about the supply elsewhere in the world.

"If we allow poverty related to water to exist in other countries, then we can expect jealousies between nations to rise, and we can expect acts of vengeance from those who are jealous," Young said.

He also said control over water could become a source of conflict in some parts of the world such as the Indus River, which runs between India and Pakistan.

"Another one would be, in fact, in Iraq, where the Tigris and the Euphrates rivers, rising in Turkey, flow into Syria, then into Iraq. And, in fact, much of Iraq's water supply is from Turkey," Young said.

Despite its own projections, the UN wants to cut in half the number of people who can't pour themselves a glass of clean water by 2015. Young said that objective would require an enormous international effort.

"We're going to have to provide those glasses of water to 270,000 people per day, every day, between now and 2015. It's an incredibly daunting task," he said.

The UNESCO report will be formally presented at the World Water Forum in Kyoto, Japan in two weeks.