Spanish authorities appeared to have prevented a major ecological disaster yesterday when they diverted a huge flow of toxic waste from Donana National Park, one of Europe's leading nature reserves. A wall of acidic water and toxic mud had rushed into the Guadiamar River in southern Spain on Saturday after a waste reservoir at a Canadian-owned mine ruptured.
The spill cut a 30-km path of destruction along the river's banks, damaging thousands of acres of crops and killing birds and fish.
The Environment Minister, Ms Isabel Tocino, said engineers had succeeded in blocking off the river, contaminated by five million cubic metres of toxic material, before the flow reached the park which has been designated by UNESCO as a world heritage site.
"The contaminated waters will not reach the wetlands because all the systems that were put in place worked," she said.
However, Greenpeace said the situation was not under control and the environmental group sent its ship, MV Greenpeace, to the area to investigate.
The crisis began when a dam at a holding pond at the Los Frailes mine, run by Canada's Boliden Ltd., burst. Toxic liquids spilled into the Guadiamar towards Donana 50 km to the south.
Engineers scrambled to build makeshift dikes to protect the 185,000-acre park - a vast sanctuary of marshlands, forests and sand dunes. They diverted the tainted water through channels to the larger Guadalquivir River and then out to sea in the Gulf of Cadiz.
The spill, near the city of Seville, created a black stain on the surface of the Guadiamar.
Ms Tocino said she had asked a provincial judge to investigate the mining company for possible violation of environmental law and urged local government officials to order a stop to mining operations at the site until further notice.
Although the park appeared to be out of danger, a farmer's group estimated that 25,000 acres of crops along the river banks were damaged by the spill, which carried toxic residue from zinc, lead, copper and silver mining.
The river banks were littered in some places with dead fish and crabs.
State radio said preliminary estimates put crop losses at 1.5 billion pesetas (£7.5 million) but environmentalists said it could take decades for the ecosystem to recover.
The Guadiamar is the main source of fresh water for the park, which shelters more than 250 bird species and attracts 40,000 migrating birds each year. The park, created in 1969, is also home to two of Europe's most endangered species, the Iberian lynx and the imperial eagle.