"This is an unprecedented crisis," said Guido Bertolaso, the civil protection chief. "These lakes are our last and most precious resource."

About 50 dams in the Alps are used to retain and control the flow of water in the river, which normally provides electrical power and irrigation to the northern part of the country along the its 1,050-kilometer (650-mile) course to the Adriatic.

Experts sayd that opening the dams would, at least temporarily, bring the river up to the minimum daily flow of three million cubic meters needed to cool electric turbines and water the fields.

Bertolaso said it was necessary to hold out for two more weeks until the harvest begins. Once factories close down for the summer vacation in August the demand for water will fall substantially, he said.

The Po fell to a record 7.58 metres (over 24 feet) below its normal level earlier this week. The region accounts for some 35 percent of Italy's agricultural production.

TERRA.WIRE