Spanish rainfall record: 400 litres per square meter in 24 hours

The storm Dana hit the South-East of Spain in mid-September. It left the extreme amount of 400 litres of rainfall per square meter in the region Vega Baja del Segura (Alicante) in 24 hours. According to the Spanish weather institute Aemet the town Orihuela in Alicante even received a total volume of 521 litres per square meter. Due to the storm the area completely flooded and six people died.

The heavy rainfall was caused by a collision between cold air from the Pyrenees and warm air on the peninsula. This weather phenomenon is not new and known in Spain as the ‘gota fria’, although the intensity of the rainfall was exceptional. Aemet issued a code red weather alarm, but this could not prevent people losing their lives in the devastating floods. After the rain 3500 people had to be evacuated.

Dike breach

In the Segura river basin a dike breach caused floods in Almoradi in Alicante. Despite the floods the water reservoir in Segura has hardly recovered. The agricultural region is suffering from extreme drought for years. Before Dana arrived the reservoir only contained three cubic hectometres of water and after the rains it reached 21 hectometres, approximately 27 per cent of its total capacity.

Aquaduct

The heavy rainfall also damaged the aquaduct (water transfer canal) between the river Tagus to Segura. The water authorities (Confederación Hidrográfica del Segura) repaired the breach as quickly as possible to ensure the drinking water supply in the region.

Flood maps

Experts are now asking the local authorities to provide flood plans, so people can prepare themselves in the future for this kind of floods. According to them the risks of living in river beds are known nationally but have to be shared with local communities. The European Floods Directive obliges authorities to provide adequate flood risk maps.