Rainwater harvesting is a technology used to collect, convey and store rain from relatively clean surfaces such as a roof for later use. This is water that would otherwise have gone down the drainage system or into the ground. The water is generally stored in a rainwater tank or directed into mechanisms that can recharge groundwater. Rainwater harvesting can provide water for human consumption, reduce water bills and lessen the need to build reservoirs which may require the use of valuable land.

Rainwater harvesting in urban areas and cities can have diverse benefits. Providing supplemental water for the city’s requirements, increasing soil moisture levels for urban greenery, increasing the ground water table through artificial recharge, mitigating urban flooding and improving the quality of groundwater are a few of the many benefits. In homes and buildings, collected rainwater can be used for irrigation, flushing toilets and washing laundry. In hard water areas rainwater is superior to city water for non-potable use. With proper filtration and treatment, harvested rainwater can also be used for showering, bathing, or drinking.

Rainwater harvesting is also effective in reducing stormwater runoff pollution into the watershed. When rain falls, it is clean, but it immediately picks up pollutants from rooftops and pavement. This pollution is carried into storm drains and then into streams. Collecting stormwater from rooftops and directing it to storage tanks so it can be used in and around a building decreases the volume and rate of stormwater runoff thus protecting local bodies of water from pollution.

Sustainability

Rainwater harvesting is one of the most promising alternatives for supplying water in the face of increasing water scarcity and escalating demand. The pressures on water supplies, greater environmental impact associated with new projects as well as deteriorating water quality in reservoirs already constructed, constrain the ability of communities to meet the demand for freshwater from traditional sources. Rainwater harvesting presents an opportunity for augmentation of water supplies allowing for self-reliance and sustainability. Sustaining the environment contributes to the overall conservation of our precious natural resources.