Planning Applications
Flooding Report - Soil Type
Page 3 of 20
Soil type
The soil is predominantly London clay to a depth in excess of 2.5 metres and therefore very poor for drainage. Water collects and remains on the surface for weeks due to the impermeable nature of the ground.
Rainfall Rates
The standard rainfall rates, for this area, for calculating drainage requirements are as table 1
Table 1
Storm Event | Rain mm/hr 100 year return period | Rain mm/hr 100 year return period + 30% |
---|---|---|
15 min winter | 97 | 126 |
30 min winter | 64 | 83 |
60 min winter | 40 | 52 |
120 min winter | 25 | 32 |
180 min winter | 18.5 | 24 |
240 min winter | 14.6 | 19 |