Storage Structures collection efficiency
Clean water from the roof can be stored in Underground sumps or Rain barrels for further use after the suggested filtration methods.
Calculation of storage/recharge volume based on the average rainfall and collection efficiency: The storage or Recharge structure capacity can be calculated by the amount of runoff from your roof taking into consideration the losses due to evaporation, leakages etc.…
The optimum storage = Roof Area in Sq Runoff Coefficient(0.9)x Average Rainfall in mm, Runoff co-efficient is the percentage of water from the roof that comes down in the rainwater pipes which is taken as 90% for RCC roofs, as about 10% will be lost by evaporations, leakages etc.… Average design Rainfall of Bangalore can be taken as 32mm (970mm/30days).
Eg: If the roof area of a building is 112 Sq M, then the storage or recharge structure capacity will be 112 x 0.9 x 32=3225 Liters.
We shall first calculate the maximum amount of rainfall that can be harvested from the RCC rooftop Following details are available:
- Area of the catchment 112 Sq.m.