A dispute over a one-acre island in Lake Victoria that has fueled talk of war between Kenya and Uganda is but one instance of increasing conflict over shrinking water resources throughout Africa.
Such conflicts pit ethnic groups, races and nations against one another and are likely to get worse, fueled by a toxic mix of climate change, environmental ruin, mounting droughts and famine.
The Kenya-Uganda dispute concerns ownership of the tiny but fishing-rich Migingo Island in Lake Victoria - at 26,560 square miles, the world's biggest tropical lake and slightly larger than West Virginia.
In recent months, Uganda has sent troops and police to the island and hoisted its national flag. Members of Kenya's parliament urged the Kenyan government to set up a naval base on the lake to "deal with external aggression."
Negotiations between the two countries in March, followed by Uganda's decision to lower its flag on the island last month, appeared to have cooled tempers for a while. But on May 12, Ugandan President Yoweri Museveni told the BBC that "the island is in Kenya and the waters are in [Uganda] ... one foot into thewater and you are in Uganda."
Mr. Museveni went on to say that soon no Kenyan would be allowed to fish in Ugandan waters. The Kenyan Parliament reacted angrily to the comments, with members criticizing Kenyan President Mwai Kibaki for stressing diplomacy as Uganda annexed what the parliament members insisted was Kenyan territory.
Tensions go back three years, when Uganda arrested, jailed and purportedly tortured a Kenyan fisherman accused of poaching in Ugandan waters.
The scrap over Migingo Island is only one example of conflicts over water rights throughout Africa that often reflect the effects of climate change and land degradation.
Frank Muramuzi, director of the Kampala, Uganda-based National Association of Professional Environmentalists, said that Lake Victoria's dropping water levels - down about 6 feet in the past four years - have destroyed important breeding grounds for fish on the edges of the lake.
Shallow waters around islands such as Migingo are now among the few remaining breeding grounds for fish such as Nile perch, a leading export and foreign-exchange earner for both Kenya and Uganda.
Satellite images reveal an unprecedented shrinking of the 677 biggest African lakes. This has intensified fears that water shortages could trigger new conflicts across a continent where more than 340 million people already have little access to safe drinking water.
In Ethiopia, Lake Haramaya, once a burgeoning source of livelihood for thousands of people, is bone-dry.
In Central Africa, the once mighty Lake Chad has lost more than 90 percent of its water because of deforestation, climate change and bad policies. The lake sits on the borders of four nations: Cameroon, Chad, Niger and Nigeria.
When Lake Chad's waters began to dwindle, a significant number of Nigerian refugees went to Cameroon. In the mid-1990s, Nigerians founded more than 30 Lake Chad villages in Cameroon.
Tension rose between Nigeria and Cameroon when Nigeria established state control and public services in the Nigerian-populated villages.
The two countries went to war in the 1990s, prompting the Lake Chad Basin Commission to move in and help negotiate a truce. The commission failed; the case then was turned over to the International Court of Justice, which in 2002 ruled in Cameroon's favor.
Nigeria at first challenged the ruling, but in 2007 agreed to relinquish the territory. Many Nigerians have never forgiven their government for giving away "their" land.
The U.N. secretary-general's special adviser on conflict, Jan Egeland, called attention to the Sahel region when he visited last year. The United Nations says the region that divides the Sahara Desert from the rest of Africa is experiencing the worst effects of climate change in the world.
Mr. Egeland said he was informed that about 30 armed groups were in the Lake Chad area. The "potential for increased conflict is endless," he said.
The 17 countries of the West African region, which share 25 trans-boundary rivers, also have been involved in wrangles over water.
Dozens of people died in a series of skirmishes between Senegalese and Mauritanian farmers along the River Senegal in 1989.
Increased barriers on the border have prevented open conflict in the years since, but tensions persist.
Ghana and Burkina Faso are at odds over competing claims for water from the Volta River.
For East Africa, the dispute over Migingo Island could be a taste of conflicts to come. Lake Victoria, the source of the Nile and the lifeline for millions of people, continues to lose water.
The Nile, which supports 160 million to 180 million people in nine countries, is also in trouble. Egypt has long warned that it would go to war to protect its access to Nile waters.
A recently released U.N. study, "Third World Water Development Report," noted that while water-supply targets are being attained in much of the world, "sub-Saharan Africa and low-income Arab states are far from the target, and some risk backsliding."
By 2020, the report said, 75 million to 250 million people in Africa may be exposed to increased water stress owing to climate change, and "conflicts will likely intensify."