In July 2007 Lower Wolvercote was flooded as the water-table rose rapidly after heavy rain. Wolvercote Common and Port Meadow are natural meadows on the flood plain of the Thames and its is quite normal that they flood each winter - indeed the flooding is part of the natural cycle that makes them such a special and protected habitat and a site of Special Scientific Interest.
However, in recent years the water-table has gradually risen to less natural levels to the point where the village as well as the meadows have been inundated. Similar but less severe floods happened in 2000 and 2003. The geology of the area is mixed layers of thick blue-green Thames clay and gravel. The ground gradually rises towards Upper Wolvercote and Cutteslowe to the ridge on which most of Oxford is built and which carries the major roads, the A40 and A44. At the top of the ridge, almost twenty metres above Lower Wolvercote is the site of the proposed 'Northern Gateway' which will be built out of impermeable concrete and tarmac. Levels of run-off water will rise significantly if the development were to go ahead and most of that water will run downhill, along the layers of clay and into Lower Wolvercote.
The developers claim that that they can solve these problems with clever drainage. The past history of such developments and the difficult local geology would suggest they might not.
Michael Crofton-Briggs, Oxford's chief planner is quoted by the BBC (article link below) as saying:
'...surface water run-off caused half of Oxford's flooding in 2007 and that the problem would be made worse by the 8,000 new homes planned by 2030.
Potential brownfield development sites were already on a flood plain, he said. However, building on greenfield land outside the flood plain would cause other drainage problems, he added.
The Pitt Review into the 2007 floods concluded that surface water run-off was largely to blame for the flood damage from which people are still recovering, two years on.'
