A few weeks ago, we commented that, with climate change, water is becoming a very scarce resource. The reorganization of the rains and the demographic changes are tightening the limits of the world's water supply.
That is making scientists sharpen their ingenuity to take advantage of all the resources at our disposal. The best example of this is surely Helen Dahlke who is a professor at the University of California, Davis, but everyone knows her as "the water banker".
The new "Water Bank"
Only in California, and in the last 70 years, 62 billion liters of water have been extracted from aquifers
And no, his work has little to do with water speculation. Rather with saving the water, with storing it. Store it underground, specifically. Dahlke realized that the underground aquifers were very efficient and safe structures where we could store the water.
In addition, they are hugely large: over the past 70 years, some 62 billion liters of water have been removed from the aquifers of the Central Valley of California.
The problem is that we only know how to get it out. So far we do not have the technology to fill them and, to tell you the truth, we did not think much about them either. If we wanted them to recover, the extraction of water was forbidden and we were waiting for nature to do its job.
However, this means that, because of the structure of the soils, many liters of water "are wasted" every time it rains. That is to say, it does not filter into the subsoil. But, what if we were able to do better?
"Recharge the subsoil"?
A simple idea, but of complex execution and that, above all, we do not know how it will work in the long term
Dahlke's proposal consists of using the same irrigation and water conduction infrastructure to accelerate the process. That same infrastructure could be used during storms to redistribute water and center it in areas more prone to underground accumulation.
It seems simple, but we know so little about the right places, about the application of the techniques and how it will work in the long term that getting it started becomes very complex.
Dahlke's team has started to work selecting land with useful soil for the accumulation, but above all studying what crops can benefit from having more water than it should. Of much more than due.
According to his calculations, alfalfa, walnuts and even almonds can support very high amounts of extra water supplied by the irrigation system. This allows to 'recharge' the aquifers, while the land remains productive. It will not solve all our problems, but small innovations like this one will help us to face what awaits us.