This code of practice provides guidelines for the planning, design, construction, and maintenance of rainwater storage systems. It covers aspects such as siting requirements, material selection, capacity calculation, and water quality management to ensure the safe and effective collection and storage of rainwater for various uses.
Lays down the code of practice for the design, construction, and maintenance of various types of storage systems for harvested rainwater.
Quick Reference Values
Minimum distance from septic tank15 m
Minimum freeboard in tank150 mm
Minimum manhole size (square)500 mm x 500 mm
Minimum manhole size (circular)600 mm diameter
Maximum slope for rooftop catchment15 degrees
Minimum overflow pipe diameter100 mm
Key Formulas
Storage Capacity (L) = Catchment Area (m²) x Rainfall Depth (mm) x Runoff Coefficient
Practical Notes
Always install a 'first flush' device to divert the initial, more contaminated runoff away from the storage tank, improving stored water quality.
Ensure all tank openings (inlets, overflows, vents) are covered with fine, corrosion-resistant mesh to prevent entry of mosquitoes and other vectors.
Regular cleaning of the tank (at least annually before the monsoon) and the catchment surface is crucial for maintaining water quality and system efficiency.