Flood Prevention Box Jack at Dorny Bridge.(Thames Valley culvert)

World Tunnelling, April, 2001 by CLARKE, IAN

As part of major flood alleviation scheme covering the Thames Valley, in the U.K., between Maidenhead, Windsor and Eton to the west of London, there was a requirement to install a large cross-section culvert beneath the main railway line running between London and the south-west of England.

The scheme was required because of regular flooding along this stretch of the Thames Valley. For example in 1947 a flood, statistically expected every 50 years, affected some 2000 homes. Given the level of development in the area and the growth in population, such a flood today would be expected to affect some 5,500 homes or 12,500 people. As flooding on a more minor scale is expected every six years or so, the last being in 1990 when 500 homes were affected at a cost of...