Hello back after a while. I am sad with you for all the suffering and damage the flooding brought.
Sorry to write in english, so I can express myself better.
I spent the last 2 weeks in northern catalunya where we travelled to escape the recent floodings in the french Cevennes mountains. An area that knows very similar flooding problems.
So what causes these floodings?

1.) Its industrial agriculture and the abandon of ancient, intelligent land management of the Antique times.
In a lesser extent its also bad soil management in civilisation in general.
WATER CANNOT INFILTRATE SOILS IN A NATURAL WAY IF THE SOILS ARE DENSIFIED BY AGRICULTRURAL AND OTHER HEAVY MACHINERY, it just almost all runs off the surface flooding all beneath and carrying soil with it, the needed, lighter organic compost goes first.

In an intelligent use of soil for gardening and farming, the soil is made of mostly compost, organic material which stocks lots of water and which needs to be loose, full of useful animals like earthworms and insects that create lots of cavities in the soil. A mix of plants and trees with deep roots. Permaculture. The only way land can be maximum productive for an infinite long time period and prevents from drying, flooding, fires and so on.
Such healthy soil can stock hundreds of millimeters of water easily like a forest ground.
Now industrial farming with machines squashes and densifies any soil, and sparce cover of one kind of plant only with bare earth between the plants, makes all good fertile soil get lost over time by wind and water erosion cause almost all water runs off the surface of those hard soils, almost transformed into rock by the machines.
A healthy soil has almost no surface run off water and stocks hundreds of liters per square meter.
You can read in the american novel "the grapes of wrath" a very good description of how machine agriculture destroys traditional farming.



This is combined with intelligent water management. The hills and mountains of this country were once paradise, the garden Eden because of terrasses everywhere and waterways and water stockage systems.
You can still see the rests of those therrasses which cover almost every hill and mountain in spain, which was the origin for the wealth of spain in past times.
Now most of it is gone, destroyed by the people who destroyed the antique structures and several times later on by invadors from the north and pirats.
The Delta d Ebre is the sad reminder of what has been lost, its the fertile ground of the paradise garden washed into the mediterranean sea after the destruction of the gardens everywhere.
So in order to survive long term and avoid such desasters, a healthier, better life style with everybody doing some gardening, which is paradise anyway if done well, is needed. Surely people will be way better than now, healthier and happier and have much more time and energy for real cultural and technology development, the intelligent natural way this time.

2) Information and education, basic one is needed. With an efficient scool system and media coverage, it takes no time to learn to everybody the basics of geology, soil and weather science to easily be able to grow own food of best quality and gardens and all surfaces with dense vegetation of vegetables, medical plants and other.
Only way back to paradise. And no more eating of dead animals and such lethal nonsense any more.
The people need to get out of the industrial thinking into seeing in a landscape exactely the best, natural wa to awork on it to get maximum of harvest and life quality.
Only so everybody has enough energy and time to develop a high culture again after this low of life quality caused by industrialisation without mind.
So people and culture can developp again a maximum for the good and in less than 10 years life can be more close to paradise again as much as it is now more close to hell for almost all cause of capitalism of maximum profit.
Only so, we can prevent most of these flood, fire, disease and other catastrophies in future.

Best wishes