THE Bodleian Library, with its sublime architecture and irreplacable treasures, might appear to belong to a different world to the Osney Mead estate.

As one of the world's greatest libraries, the collections of books and manuscripts it holds are priceless, while its buildings dominate Oxford's historic golden heart.

Yet, Oxford University has come to believe the future of this 400-year-old much loved institution is dependent on what happens on a business park off Botley Road, best known for its habit of flooding.

On Tuesday, Oxford's City Council's strategic development committee will be asked to approve plans to create a £29m book depository on the estate.

And while, by any standards, building a depository to hold eight million books is a big project, far more is at stake than creating a warehouse close to the city centre.

For the depository is just the first phase of a £130m scheme, which will include the transformation of the New Bodleian Library, and ultimately the whole look of one end of historic Broad Street.

Anyone who doubts the importance the university attaches to what promises to be one of the biggest library reorganisations ever undertaken, need spend only five minutes with Bodley's librarian, Dr Sarah Thomas.

Dr Thomas, who became the first woman and non-British person to fill the most senior library post at Oxford, says a planning refusal at Osney Mead would be a disaster.

She said: "It would have dire consequences for us because we would not have a place to house our collection."

The depository came to be viewed as essential once it became painfully obvious that the accommodation at the New Bodleian in Broad Street was no longer able to cope with the ever-growing collection, which demands an extra two miles of shelving a year.

The rapidly deteriorating storage conditions, in a library revered throughout the world, also began to cause serious concern, with valuable manuscripts stored next to ageing pipes and creaking air conditioning machinery.

The extent of the problems were spelt out in 2005 when the New Bodleian humiliatingly was only granted a temporary licence by the National Archives - and that was only recognition of the fact that improvements were planned within three years.

In a sense, it has been on borrowed time ever since.

But while everyone would accept that the Bodleian had to find more book storage space, its choice of Osney Mead was always going to be controversial.

Over the last 12 months, the university has been forced to redraw its plans to meet concerns that its book depository, almost twice the height of the existing building on the former Blackwell's site, would damage views of Oxford's skyline.

The fact it would be across the road from the towering new Newsquest building, where The Oxford Times is printed, only added to the opposition.

Councillors next week will also be looking keenly at the University's elaborate plans to combat the flood risk, on an estate which was severely affected in July.

When the plan was first mooted some academics questioned the wisdom of storing rare volumes at the end of a road that several times in recent years had come to resemble the Grand Canal in Venice.

Anyone who saw Osney Mead in July, with the estate all but cut off, save for the towpath via Osney Lock, found the University's insistence that the depository site was not being built on a flood plain even harder to swallow.

But the dons have been won over and as Dr Thomas points out: "Our site remained dry in July's floods. People went in every day. The water only lapped up to the parking lot."

In any case, the university suggests the new building will be able to withstand whatever the Thames and climate change can throw at it, for a few thousand years at least.

A university briefing document is bold in its confidence. It states: "The depository will be one of the best protected buildings in Oxford, capable of withstanding floods on the scale of those in New Orleans in 2005.

"The flood defences have been designed to allow for future uncertainty, including a substantial increase in rainfall and river flow over the next hundred years. Only a one in 5,000 years catastrophe could breach its defences.

"Extensive flooding studies have been undertaken. The University has carried out an extensive hydrological survey and flood risk analysis.

"The Environment Agency also carried out thorough studies of the flooding issues on behalf of the university and supports the planning application."

The key is said to be an impermeable wall and gates over 2m high.

All books will also be stored above ground level at an appropriate temperature and humidity, protected by state-of-the-art fire protection and security measures.

Claims that the impermeable wall would merely result in flood water being dispersed to neighbouring properties are rejected. Large underground areas of the site engineered to collect and store light floodwater would mean neighbouring properties would actually be better protected because of the university's heavy investment, said Dr Thomas.

But Oxford Civic Society chairman Tony Joyce remains doubtful. "To put some of the most precious documents in the world into one of the predictably most hazardous flood risks in the country is incomprehensible enough," he told The Oxford Times. "To compound these risks by adding to the existing problems of drainage and the huge run-off from the very large roof area must be unacceptable."

The roof was in fact substantially redesigned to meet the objections of Oxford Preservation Trust and others who complained that the structure resembled "a great box-like shed".

The first application was withdrawn before designers came up with an undulating roof structure, varying from 12m at its lowest point to 20.2m at its highest, was introduced, in a bid to offset its size and impact.

But OPT director Debbie Dance is unimpressed. "It is a different colour and it has an undulating roof. But it remains essentially a very large warehouse in the wrong place," she argues.

"Sophisticated techniques are employed to demonstrate that the impact won't be too bad. There are many photographs and many explanations. But none of it replicates the truth of what the eye will see.

"A trip around Hinksey along the A34 gives a clear view of the blue and white Newsquest building.

"Imagine a further building of similar height and seven times the size, albeit designed to blend in, but nearer to Oxford University's core and its spires."

Rather than going back to its designs, the university should have found an alternative site, said Ms Dance.

From the university's point of view the depository needed to be within the Oxford ring road, to ensure the books could be easily transported to readers' rooms.

It means books ordered by students could be quickly transferred to Broad Street by van. One round van trip per day is envisaged, with the university all too conscious that anything that adds to the congestion at Frideswide Square, the worst bottleneck in the city, would not impress city councillors.

It also made the case that an important part of Oxford's history needed to remain within the city, even if this library section would see cranes operating and latest machinery to access the books.

In any case, the University seems to have gone too far down the road to Osney Mead to contemplate starting again.

The University is presently to pay £360,000 to store millions of books at a disused salt mine in Cheshire with the bill set to rise to £450,000 next year.

Dr Thomas said: "My choices would be to buy fewer books, close libraries or shorten hours because we would not have the money to pay for extra storage. It's a downward spiral. It is really precarious right now."

And there are clearly "sweeteners" for the city centre, with the prospect of the New Bodleian Library being opened up to the public.

With the New Bodleian, opened by King George VI in 1940, no longer fit for purpose as a book store, a £50m refurbishment plan now offers the chance to open up the Bod to the whole city, said Dr Thomas.

"We thought about what we should be doing with a building in such a strategically important location. We wanted to make it welcoming and to take the opportunity to share this great institution and its resources with the public."

The plan would see land outside the building lowered to pavement level and the creation of a new public square. The forbidding barred windows along Broad Street would become doors, with a cafe planned and a terrace created on the library roof. Best of all, an exhibition gallery would be created to display Bodleian treasures.

"Rather than see it as a warehouse, people should view it as a springboard to the renovation of an important part of central Oxford," said Dr Thomas.

Later, the university will be coming forward with detailed plans for a new £35m lending library as one of the landmark buildings on the Radcliffe Infirmary site, which is being transformed into the university's main campus. Officers are expected to recommend that the strategic committee approves the depository scheme next week.

The woman, who arrived from Cornell University, knows well enough it would represent an important legacy for those who have waited so long to see Broad Street transformed and the Bodleian modernised.

But for some it will be achieved at a cost of impacting on views of Oxford that took the university 700 years to create.

As warehouses go, you would be hard pressed to think of a more important one proposed in Oxford.