The phenomenon of flooding occurs in Bilbao cyclically, 39 flooding events are described quite in detail since 1380. The last one in 1983 caused by a cold drop phenomenon, with a rainfall in 24 hours equivalent to the average half year precipitation, affected a big part of the city and left the nightmare of 39 casualties an over 1.2 billion euros in damages on assets.
Bilbao decided to take advantage of the disaster and made a radical transformation plan for the city, but also determined that the city should be better prepared for the next flooding that will take place for sure in the future.
Beside the immediate actions to repair the damaged infrastructures during the flooding, the Nervion riverbed was cleaned and reshaped, also the river was diverted in the most sensible places to increase flow capacity. Most of the wastewater drainage systems were modified and improved.
The Basque Meteorological Service has been created to improve local weather forecasting. Besides, new instruments have been allocated for them, cloud and rainfall detection radar, water-level alert systems, etc. in order to implement a very early forecast and detection of flooding hazards.
The Canal of Deusto, now under construction, will allow bigger flow of water in Bilbao decreasing the risk of flooding in the city.
Flood Prevention Plans have been designed to analyse and evaluate the hazardous areas and take action in diminishing eventual affection, better event management and easier and faster remediation. The plans have been elaborated at both whole drainage system and particular river basin levels.
At Bilbao Municipality level a Municipal Emergency Plan (PEMU) where local action protocols are collected has been developed.
All these plans are in continuous analysis for improvements. Projects like Flood-serv help in this continuous improvement programmes providing benchmarking with other experiences and binging in new ideas and concepts as the involvement of citizens in the detection, management and recovering in flooding events.