OXFORD University's Bodelian Library is weighing up its options after city councillors rejected plans for a £29m library book depository in West Oxford.
The world-famous library wants to build the depository at the Osney Mead industrial estate.
But last night, councillors refused planning permission because of concerns over possible flooding problems and the impact the proposed building could have on views of the dreaming spires.
Following the meeting, Colin Cook, Labour city councillor for Jericho and Osney, said the Bodleian Library could appeal to a Government planning inspector.
He added: "It was interesting that Bodleian staff did not declare on the night that they were going to appeal.
"I would now expect them to go for a belt and braces approach and launch an appeal while at the same time considering sites inside and outside the ring road.
"I think they will now have to have a more serious look at sites outside the ring road. It usually takes six months before a planning inquiry is heard and they might not want to wait that long."
The decision by the full council overturned planning permission granted by the strategic development control committee in September.
Bodley's Librarian Dr Sarah Thomas said the decision was "the democratic process at work".
She added: "I think we have a very good design.
"We worked with the Environment Agency, English Heritage and the city, and ultimately a solution will present itself.
"We desperately need more space."
Dr Thomas added it was too early to talk about an appeal, or consideration of alternative sites.
Whatever course of action the Bodleian decides to take, it needs to act fast because it is running out of space for its books, as the university acquires 5,000 a week.
At present, the university pays £360,000 a year to store millions of books at a disused salt mine in Cheshire, but the cost is set to rise to £450,000 next year. There is also a Bodleian store in Nuneham Courtenay with 1.3m volumes.
Liberal Democrat councillor Sue Roaf told the meeting: "This building would be a flooding nightmare.
"If such new developments are sanctioned, the lives of hundreds of families could be shattered."
Fellow Lib Dem Alan Armitage added: "The landscape of Oxford could be ruined by this building."