Moving two rivers from the middle of the Terminal 5 project site at London's Heathrow airport to a new alignment around the western airport perimeter was a critical and highly environmentally sensitive sub-project of the T5 programme. The rivers diversion had to be completed before the original river structures could be demolished to enable continuation of the main terminal development. As described in this paper, the £45 million diversion project included the creation of two 3 km long river channels, phased realignment of 3 km of highway and landscape works to the western boundary of Heathrow.