Building work on Birmingham's £193 million library in Centenary Square will begin on November 24 next year, writes Public Affairs Editor Paul Dale.
In an unusually detailed timetable released by the city council last night, officials named the day that construction would begin and said the entire project would be completed on December 17 2012.
The decision to be so specific is understood to have been taken by the council leadership in an attempt to end scepticism about the feasibility of delivering a world class library on what critics say is a site of insufficient size.
It also emerged that the new library is to be built on top of an old canal. Specialist engineers hired by the council say the discovery should make no difference.
An investigation by the Scott Wilson Consultancy found that, under a "worst case scenario", the water table underneath Centenary Square could rise by about 55 feet during the lifetime of the library building.
The consultants concluded: "In the final design of the library basement we would expect expert hydro-geological advice to be sought to facilitate a more accurate prediction of the future groundwater levels at this site.
"We would note that in our view a change in the predicted water level would not significantly affect the technical feasibility of the scheme."
The water table issue is important because the four basement floors of the new building will be used to house the archives and for storage purposes.
The library scrutiny committee, which met yesterday, expressed concerns about ground water risks.
Councillor John Alden (Con Harborne) said: "I am concerned that the engineers adequately ensure the old canal has been properly capped off. I have been told it has been filled in but if we are digging a big hole we need to be sure we are not going to get leakage."
There were also demands for assurances that the size of the library, at 31,000 sq ms, would not be further reduced in order to keep the project within budget. A former plan to build the new library at Eastside envisaged a 38,000 sq m building.
Committee member Coun Mick Wilkes (Lib Dem Hall Green) said: "There has been a relentless scaling down in terms of size, I can't think of a single element that has gone up in size."
Brian Gambles, the council's assistant director of leisure, said he was satisfied a world-class library could be delivered in a 31,000 sq m building.