Run-off Calculations

The route of the path is largely downhill, on chalk/flint sub-base ground with minimal drainage capacity. Given its location and the 5.5 hectare area of the site, which will likely be 75% built over with homes, driveways, roads and other non-porous surface treatments, this means some 33 million litres of runoff rainwater (1mm of rain over 1 square metre = 1 litre, 10,000 square meters per hectare, 800mm average annual rainfall, developed area of 4.125 ha) will flow off the site and downhill to lower areas of the village. The path of least resistance is likely to be the cycle path, which in periods of heavy rain is likely to turn into a river, with attendant risk of flood impact to those properties at the lower end of the path on Cart lane