Drainage works account for an unusually high proportion of the infrastructure costs at the Donington development. The drainage and pumping station are together worth some £4M of the £10M total. 'You would normally expect 8%-10% of the cost of a development to be in drainage, ' says McGinty.
Provision of a huge storm water capacity creates the demand for such major works.
Dean & Dyball and drainage sub-contractor Wilmat Construction are developing the main carrier drain through the central spine road and installing stub pipes which future developments will use.
Although the power station is long gone, much remains under the surface. The foundation block is on the road alignment and the drainage route had to be carved out. The maximum diameter of the pipe is 2.2m and it runs up to 7m deep to give the fall needed. Some 6000m concrete had to be demolished.
'We reckon the actual foundation block is close to 100,000m 3 of reinforced concrete, ' says McGinty.
The route runs through the flood plain of the River Trent and extensive dewatering has been needed. This was carried out from both sides, as mudstone would otherwise have isolated the system. Ground levels were temporarily reduced by 1m prior to starting because of work at the limits of the dewatering system.