The plant is one of nine that Acuamed, part of the Environment Ministry, plans to put out to tender by the end of June, and will provide water for irrigation and for human consumption.

It is part of a plan to build 26 desalination plants between 2005 and 2009 to ease water shortages along Spain's Mediterranean coast.

Spain suffered the worst drought on record in the 2004/2005 hydrological year. Reservoirs have recovered substantially thanks to recent rain, but the Environment Ministry said on Friday that rainfall was still below average.

"Despite the snow and rain that has fallen in winter and spring, we are in a several-year-long cycle of drought," it said in a report.

In much of Spain water levels have risen substantially, but in some areas farmers still face difficulties, the report said, mentioning fruit growers in the Segura basin in the southeast who are struggling to keep their trees alive.