"El Nino (seasonal warming), climate change and low rainfall could increase drought in the country, and cause a critical situation in the first quarter of 2010," a Conagua statement said.

Farming and some water supplies across the country have already been hard hit by this year's drought.

Supplies for both public and private use could be affected next year, the statement said, pointing to record low levels at the Cutzamala reservoir which supplies the capital's urban sprawl.

The main problem in and around the city of some 20 million people, which once sat on lakes, was the over-exploitation of aquifers, the statement said.

Mexico City authorities have this year been carrying out water cuts under an emergency plan to help save water and work on much-needed repairs.

The head of the National Farmers Confederation meanwhile last week estimated that the current dry spell would cause losses of up to 15 billion pesos (1.16 billion dollars).

Cruz Lopez Aguilar said it was the country's worst drought in 70 years.

El Nino is an occasional seasonal warming of the central and eastern Pacific Ocean that upsets normal weather patterns from the western seaboard of Latin America to east Africa, and potentially has a global impact on climate.

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