Reservoirs by R S Thomas appeared in “Not That He Brought Flowers”, published in 1968. It was written soon after the opening of Llyn Celyn and Llyn Clywedog.
There are places in Wales I don't go:
Reservoirs that are the subconscious
Of a people, troubled far down
With gravestones, chapels, villages even;
The serenity of their expression
Revolts me, it is a pose
For strangers, a watercolour's appeal
To the mass, instead of the poem's
Harsher conditions. There are the hills,
Too; gardens gone under the scum
Of the forests; and the smashed faces
Of the farms with the stone trickle
Of their tears down the hills' side.
Where can I go, then, from the smell
Of decay, from the putrefying of a dead
Nation? I have walked the shore
For an hour and seen the English
Scavenging among the remains
Of our culture, covering the sand
Like the tide and, with the roughness
Of the tide, elbowing our language
Into the grave that we have dug for it.