A £20M Environment Agency project to alleviate flooding near Heathrow Airport has won the ICE London Merit Award 2002.
The winning project team, which included consultant Halcrow as engineer and Dean & Dyball as contractor, collected the award from Institution president Mark Whitby at the ICE London annual dinner last month.
The Stanwell Diversion Flood Alleviation Scheme has reduced the risk of flooding to the village of Stanwell Moor - situated on the south west perimeter of Heathrow Airport - by providing a new flood channel for the River Colne.
With part of the new channel running through an old landfill site, great attention was given to environmental issues. Two new wetland areas and a new lake were created, and contaminated groundwater discharged back into the landfill site through a series of settlement lagoons.
Groundwater itself was a further complication, with excavations up to 4m deep penetrating below the water table. To prevent groundwater ingress, sheet pile cut off walls were driven through the gravel into the underlying clay.