It was previously thought smaller libraries would be merged as part of efforts to save Â£18.9m next year.
But Hungerford community magazine editor David Piper said he had obtained documents detailing plans to close the libraries instead.
West Berkshire Council said it had no choice but to consider closures in the face of cuts.
Libraries will be part of a budget proposal announcement on 15 February.
Mr Piper, 74, said libraries were as much a social hub for the older community as a place for books.
He said the closures "would be an unbelievable loss."
"People won't be able to come down and get books, have a chat, have a laugh, have a cup of coffee.
"Especially the older folk, what the devil are they going to do for books?"
West Berkshire Council currently runs nine libraries as well as a mobile library service.
Previously published budget cut included merging the libraries in Burghfield and Mortimer.
A council spokesman said: "We know our communities value libraries immensely and it's with a heavy heart that we have to look for further savings within our library service.
"Local residents should be under no illusion about the scale of the challenge we face in finding Â£18.9m savings - around a fifth of our entire budget - in one year.
"It means we now have to consider areas, such as reducing the number of libraries, which even a few weeks ago would have been unthinkable."
Leaked proposals suggest the majority of libraries in West Berkshire will close, the BBC has been told.