Bordeaux was officially declared a UNESCO World Heritage Site back in July 2007 ( http://www.decanter.com/news/127668.html ) and has since seen a rise in visitor numbers of around 25% according to figures from the Tourist Office at the end of 2008.
Unesco recognition is well known to enhance tourism and therefore the economic development of an area. In recognition of this, in 2008, the Unesco Heritage Center received a World Tourism Award for its outstanding achievements in the travel industry (for a very interesting look at this, read http://www.unausa.org/Page.aspx?pid=1334 )
The problem for Bordeaux are the plans to build a new bridge across the Garonne river in the city centre, between Bacalan and the Bastide. It is badly needed, because there is currently only one main bridge in the centre of town (in the photo below, and yes it is rather attractive, while the new one will be much more modern in design), and traffic is usually snarled up around it. But for the UNESCO committee, it will affect the look of the historical centre, that was awarded UNESCO status for its perfect preservation of its 18th century heritage.
Mayor Alain Juppe has said he favours the bridge over UNESCO, if he has to choose, but is doing everything he can to find a compromise. The local newspaper this morning reported that work may begin as early as September. Negociations with UNESCO took place throughout June (although reportedly Juppe came back early from one of the them in Spain so as not to miss the Fete de la Fleur, very sensible man). There were suggestions from UNESCO to create an underground tunnel between the two sides of the river rather than a bridge but that idea has been rejected because of cost, and also the effect on cylcists and pedestrians.
They have submitted new plans that modify the bridge and allow boats to pass underneath and is (they hope) more aesthetically pleasing, but are still waiting to hear what UNESCO decide.