From the fate of those family farms to geopolitical disputes between Israel and its Arab neighbors over Jordan River water, international wrangling over the world's most precious commodity has become increasingly common.

Such disputes, over issues such as water management, sanitation, privatization and cross-border disagreements like the one dragging on US-Mexico relations will be the focus at the 4th World Water Forum from March 16-22 beginning in Mexico City this week.

Botello's farm just inside Mexico relies on water seeping across the border from the dirt bed of the All American Canal, which runs for 80 miles (129 km) through US territory from Yuma, Arizona, to Calexico, California.

The US-based Imperial Irrigation District water utility is planning a two-year, $200-million overhaul of the canal that will stop the seepage, aiming to save US residents some 67,700 acre feet (83.5 million cubic meters) of water a year.

But Mexican environmentalists warn the project to update the canal, which has irrigated land on both sides of the border since it opened in 1940, could dry up wells and drive up salinity levels in Mexico, and local residents are worried.

'A BIG TOPIC'

Faced with losses, some of the farmers brought civil actions in the United States seeking to stop the project to reline the canal. Most were tossed out by a US federal court in February, but one is set to be heard next month.

"Right now our ranch is like a little oasis," Botello said on the southern banks of All American canal's towering levee.

"But without the runoff from the canal, the trees and the pasture could all die," she said.

Disagreements over rights to water catchment areas have caused political tensions between many countries, including Israel and its Arab neighbors, Bangladesh and India, and African countries that draw water from the Nile River.

"It's a big topic. There are more than 100 countries in the world that share watersheds and most of them don't have treaties to cover disputes," said Jose Antonio Rodriguez, the chief advisor to Mexico's National Water Commission and an organizer of the international meeting.

"With a growing global population and increased demand for water, this kind of problem is becoming more common, and we need to find solutions," he added.

Mexican government officials say they are in talks with Washington to find a solution to the canal dispute.

"The leaks from the canal have, over time, generated rights in Mexico, and there should be a negotiated solution to the problem," said Jose Guadalupe Osuna, a federal deputy for Baja California state.

Bob Walsh of the US Reclamation Office, which governs dams along the canal, said Mexican worries about the canal lining plans were overblown.

"The lining is only for 23 miles (37 km) of the system ... the concern by the Mexican farmers is that some of the water they receive as seepage will simply go away, whether that is true or not I don't know, that is one of the things the courts are trying to decide."