Botany · Ch 8 — Environmental Issues
Rain water harvesting – RWH
Rain water harvesting – RWH
Rainwater harvesting (RWH) is the deliberate, on-site accumulation and storage of rainwater for later reuse, rather than allowing it to simply run off and be lost. Water collected from rooftops, terraces or natural catchments such as rivers is directed into a collection system — typically passing through a sand filter to remove impurities — and then either stored directly in a tank for domestic use or allowed to percolate into a pit or well, recharging the local groundwater table. At the scale of an individual house, a simple set-up channels rainwater through a canal and sand filter into a storage tank, with any overflow diverted to a well rather than lost; at the scale of an apartment block or larger building, a multi-stage system adds a sensor-controlled collection tank and a dedicated suction-tank filter stage before final storage and distribution to residents. Because it needs no large land acquisition and displaces no population, and works in both urban s …
What this figure shows. A composite figure captioned 'Pictures of Rain Water Harvesting Structures in Ooraniers' (traditional Tamil Nadu village ponds), diagrammatically showing an individual household rainwater-harvesting set-up: a rainwater collection canal feeds into a sand filter, which purifies the water before it reaches a storage water tank; an overflow pipe carries excess water from the tank to a nearby well, so that once the household tank is full, surplus rainwater still recharges groundwater via the well rather than being lost as run-off. Labelled components include the drain pipe, sand filter, water tank and well, illustrating a simple, low-cost harv …
What this figure shows. A labelled schematic captioned 'Rain Water Harvesting Structures in Water Supply sources', tracing the path of rainwater through a building-scale harvesting system in four stages: a rainwater inlet where water collecting on a terrace/roof enters a downpipe; a collection tank fitted with a sensor that directs the water onward; a suction tank containing a filter that removes impurities from the water; and finally a water storage tank from which the treated water is supplied onward to flats/apartments for domestic use. The figure illustrates a multi-stage filtration-and-storage design suited to multi-unit residential buildings, in contra …