OXFORD University's plans to store millions of valuable books in a depository at Osney Mead look to be entering a troubled new chapter.

Oxford Preservation Trust has confirmed that it will oppose the university's revised plans to create a £29m depository, able to hold 7.8m books. The trust says the book store is being built in the wrong place and will urge the university to find a new site.

The scheme had been due to be discussed by the central south and west area committee next Tuesday.

But it has emerged that the Environment Agency wants more time to examine the issue of flooding, which has dogged the scheme since it was first put forward.

Academics had originally expressed concern about the flood risk to millions of books being moved from the Bodleian to the Osney Mead industrial estate, some rare and irreplaceable.

Conservationists also protested about the impact the huge depository, on the site of the former Blackwells building, would have on the Oxford skyline.

The university withdrew its original scheme, producing a revised plan that raises the groundfloor level and places a flood defence wall around the building. A spokesman promised it would be "the best defended building in the city".

But the Environment Agency wants to further examine whether the large structure might increase flood risk to other premises on the industrial estate.

It is also now clear that the revised plans have failed to win over critics like the Oxford Preservation Trust.

Trust director Debbie Dance said: "The new designs clearly try to mitigate the impact of the building, with changes to its shape and colour. But in our view it is in the wrong place. The effect on views will be devastating."

The new depository is viewed by the university as crucial to the biggest expansion plan in the Bodleian Library's 400-year history.