This will be useful material to add to the information in Chapter 11 Saving wetlands in Doñana on pages 110-117 of Decision Making Exercises for GCSE Geography.

As far back as 1988 a group of conservationists brought to the notice of the European Commission that the iron pyrites mine at Aznalcollar 60 km north of Doñana National Park constituted a threat to the fragile ecosystem of Spain's most important wetland. More recently in 1996, a danger warning was issued by a former mine executive that two reservoirs containing toxic waste were unsafe.

Figure 1 Location of Doñana

At 3.40am on Saturday 25 April 1998 the 1.3km-long dam of a reservoir was breached. A 500m-wide black wall of toxic waste containing cadmium, lead, zinc, chromium and mercury advanced down the Guadiamar River towards Doñana.

Existing barriers on the Guadiamar were closed and three emergency barriers were constructed in an attempt to protect the Park from the 5 million cubic metres of toxic waste (water and sludge) by diverting it around the Park and into the fast flowing Guadalquivir and then to the sea.

Despite claims by the Environment Minister that Doñana had not been affected by the waste, environmentalists including the Spanish Ornithological Society (SEO), the RSPB and the Spanish branch of the World Wide Fund for Nature were deeply concerned. The RSPB said that both the park and the Entorno had been affected.

Doñana National Park

• Birds, flora, amphibians and reptiles.
• During the spring ¹/₄ million birds nest in the park.
• Birds have been attracted to feed on the poisonous sludge outside the park; in due time the level of poisons may be sufficiently high enough to cause death.
• Wetland sediments could be affected by toxic waste which would get into the food chain.
• Spring thunderstorms now affecting the area could cause sludge in the Guadiamar valley to flood the park; it is imperative that sludge is cleared before the autumn rains arrive but it is doubtful whether this will be achieved.
• Concern exists as to whether the Guadiamar, the main source of water, will be allowed to flow through the park again by the autumn. The wetlands need to be covered for 6 months of the year. The park has only just recovered from a five year drought which killed much wildlife.

Doñana Natural Park

• A large part of this area has also been devastated by the toxic waste.

Guadiamar River

• Slick of sludge 0.6m thick and 50km long lines the banks.
• Vegetation on the river banks has been killed.
• All the fish poisoned: 20 tonnes had been gathered up and removed by the end of April.

Farmland in Guadiamar Valley

• 6070 ha covered with sludge.
• Affected - fields of rice, tomato, sunflower, cotton, orchards and olive groves. Damage is estimated at 1.5 billion pesetas (£6 million).
• Fields could be unusable for up to 25 years.
• Rain falling on sludge may cause pollution of the underlying aquifer.

Fish farms and fisheries at Sanlucar de Barrameda

• At risk - heavy metals could be deposited on river beds where many species feed.
• Fisheries in sea at risk.
• Fishermen felt that the waste should not have been diverted into the Guadalquivir, threatening their livelihood.

Water supplies

• A water shortage is likely.
• Water from the Guadalquivir is unsafe for livestock and irrigation.
• Drinking water from wells in the Guadiamar valley is also suspect.
• Irrigation water from deep wells could also be affected.

Tourism

• Some bookings in Sanlucar de Barrameda have been cancelled.

Toxic waste in Doñana National Park and Natural Park

THE CLEAN UP:

Despite the gravity of the situation it was to be well over a week before immediate and long term plans for a clean up operation were drawn up by the Environment Minister and several more days before action was taken.

• The sludge is to be taken back to Aznalcollar and dumped in an empty mine. It is feared that on hot windy days the fine toxic dust will affect crops and humans.
• Costs are estimated at over £1 billion.
• Restoration of fields to agriculture once the sludge has been removed could involve the repeated sowing of special plants which will absorb the toxic metals.
• 20 tonnes of dead fish had been cleared up.
• By the beginning of June the RSPB was sceptical that the spillage would be cleared up by the autumn. It now seems likely that it could take a year to complete. There is also increasing concern about the health risks imposed by the toxic dust.

For more information on Doñana, visit http://www.cma.caan.es/aznalcollar/ingles/i_idxaznalcollar.htm.