How to calculate the capacity Rain Water Harvesting Tank you need
- Click on the nearest climatic zone (according to the city) to your location on the alphabetical list in the below section.
- Read minimum daily service level you require from the relevant table, according to your roof size (area) and the tank size (capacity).
Run off coefficient: 0.8
Tables are derived by Mansur’s Graphs: Mansur U. An Investigation on Rainwater Harvesting in Sri Lanka with Emphasis on Quality of Rainwater and System Design. M.Sc. Thesis University of Peradeniya, Peradeniya, Sri Lanka