Unit color method people Filter storage terrace capacity rainfall reliance flat RCC courtyard turbidity dependence clean silt dry seasons roof debris stone roofs crucial role sloping roofs contamination other surface key components catchment area Transportation microorganisms other materials allegianceindia initial flushing watering gardens various purposes harvesting system rechargeable water first flush device Rooftop Rain water unpaved/open ground democratic routines Allegiance Enterprise sustainable water usage UV-resistant water pipes straightforward technique traditional water sources conventional water sources Allegiance Water Management Rooftop rainwater structures Rooftop rainwater harvesting potable household activities potential atmospheric contaminants