fog Dew nets wells tanks shafts schools cisterns flooding Industry Droughts aquifers practice centuries hospitals boreholes deep pits livestock reservoirs dry spells South Asia Advantages households other tools urban areas maintenance Limitations dry periods communities Agriculture Applications Supplemental soil erosion Domestic Use other regions water demands Storage Space Installations neighbourhood roof material runoff impact drinking water Energy Savings green” rooftops allegianceindia distant sources proper treatment Rainwater quality public facilities Proper filtration domestic purposes Climate Dependency storage containers Initial Investment water availability Collection Process sustainable cities roof-like surfaces groundwater levels food security goals Initial setup costs Harvested rainwater industrial processes rainwater catchments Groundwater Recharge Allegiance Enterprise Environmental Benefits local climate patterns atmospheric conditions small-scale irrigation Historical Significance Independent Water Supply alternative water source Adequate storage capacity Allegiance Water Management Rooftop rainwater harvesting unreliable municipal water supply