How to Find out the Quantity of Stormwater run-off in a Catchment Area
A catchment area of 20 km2 consists of two-third rural and one-third urban area. The rainfall intensity in this area is recorded as 25 mm/hr. Find the quantity of stormwater run-off in the area in litre per second. ‘K’ for rural area is 0.30 and urban 0.50.
Quantity of stormwater run-off
- K = Coefficient of run-off
- i = Rainfall intensity (in mm/hr) = 25 mm/hr
- A = Catchment area in hector
Rural catchment area = = 13.3333 Km2 = 1333.33 hector.
Urban catchment area = = 6.6666 Km2 = 666.66 hector.
The quantity of storm water run-off from the rural catchment area
Or, = 27.777 m3/sec = 27777 litres/sec
The quantity of storm water run-off from the urban catchment area
Q = = 23.125 m3/sec = 23125 liters/sec