Fresh water and masonry

People are worried for the future
For themselves, their son or daughter
You may not have enough to suit your
Own and offspring’s need for water.

Rising seas and melting glaciers
Means there’s less than you think
The near future to face yours
Looking for good water to drink

Desalination can use the sea
To make that salty water sweet
But it takes much energy
And pollution we must beat

Far too polluting and unsustainable
So another way is sought
To make fresh water obtainable
So our best ideas are brought

And if a concrete masonry sphere
With very high compressive strength
Is sunk to depth then it is clear
It is an acceptable length

To harvest water through a filter
Using free high pressure of the deep
A concrete sphere, once I built her
To collect that filtered seep

Of freshly filtered sweet clear water
Collected for almost free
For your son or your daughter
If we should do it why can’t we?