Gwynedd Council is the latest to lay out potential library cuts, with eight of its 17 libraries facing closure.
The Welsh council has said the current level of service is "not sustainable", as it seeks to make budget savings of £50m over the next three years.
The Daily Post reported that rural library branches open for less than 20 hours a week are the most likely to face cuts. Though the council is likely to ask volunteers to step forward and help with the running of affected libraries, many could see their doors shut permanently.
Caernarfon Cllr Ioan Thomas, who has a responsibility for libraries on Gwynedd council, told the paper: “A review of the library service conducted by a panel of councillors showed that the current service as it is is not sustainable, and that a clear vision is needed to plan for the future and to respond to the challenge of digital developments and budgetary constraints. It is therefore accepted that we must consider changing the provision."
It is expected a public consultation into the cuts will be held next year.
In 2013, Gwynedd council leader Dyfed Edwards told the Welsh Local Government Association Conference that entire library departments could be at risk as the result of budget cuts, saying that councils would be forced to consider services "in their entirety".
The news comes just a day after the release of the long-awaited Sieghart Report into libraries in England, which encouraged government investment in Wi-fi and a digital network for all libraries.