RAINWATER HARVESTING AND ITS METHODS
Water Harvesting as, “The collection of rainstorm-generated runoff from a catchment (the area from which the water flows into bodies) to provide water either for immediate utilization as irrigation or for subsequent utilization by storing in above-ground ponds or aquifers.” In layman’s terms, water harvesting is the direct collection of rainwater.
There are mainly two methods of rainwater harvesting are Surface runoff harvesting and Rooftop rainwater harvesting methods.
Although three–fourths of earth is water, a minute amount is available for human consumption or irrigation. Moreover, due to increasing global temperature and population, there is a lack of potable water sources (e.g., rivers, lakes, or aquifers) in semi-arid and arid areas.
The global problem is rapid industrialization and disposal of chemical waste into water-bodies leads to pollution of freshwater sources. On the other side, rainwater is the only supply of fresh water left. To deal with the water crisis, water harvesting is adopted.
“The earth, the land, and the water are not an inheritance from our forefathers but on loan from our children. So, we have to hand it over to them at least as it was handed over to us.”
Purpose of Rainwater Harvesting
- To serve as domestic use with proper treatment (drinking, watering garden).
- To serve as landscape irrigation without filtration especially for dryland farming.
- To increase groundwater recharge which further increases soil fertility.
- To reduce stormwater discharges, urban floods, and overloading of sewage treatment plants; Saves the fresh surface water free of fertilizers, pesticides, metals, and other sediments.
- To reduce seawater ingress in coastal areas.
Rainwater Harvesting Methods
There are mainly two methods of rainwater harvesting,
- Surface runoff harvesting
- Rooftop rainwater harvesting
Surface runoff harvesting
In this method, rainwater flows away as surface runoff and can be stored for future use. Surface water can be stored by diverting the flow of small creeks and streams into reservoirs on the surface or underground. It can provide water for farming, for cattle and also for general domestic use. Surface runoff harvesting is most suitable in urban areas.
Rooftop rainwater/storm runoff can be harvested in urban areas through:
• Recharge Pit
• Recharge Trench
• Tubewell
• Recharge Well
Rooftop rainwater harvesting
It is a system of catching rainwater where it falls. In rooftop harvesting, the roof becomes the catchments, and the rainwater is collected from the roof of the house/building. It can either be stored in a tank or diverted to artificial recharge system. This method is less expensive and very effective and if implemented properly helps in augmenting the groundwater level of the area.
Roof Top Rainwater Harvesting Method can be installed in the following places
- Residential Homes or Villas
- Schools, Colleges and other Educational Institutions
- Apartments/Flats, Multi-Storey Buildings
- Government Buildings
- Industries, Factories, Mills
- IT Parks, Hotels, Restaurants, Resorts
- Swimming Pools, Stadiums
Different Types of Filter Used In Rainwater Harvesting
- Sand Gravel Filter
- Charcoal Filter
- PVC-Pipe Filter
- Sponge Filter
Advantages of Rainwater Harvesting
- Very cheap method to collect and store water from the roof.
- Decrease the demand the water.
- Decrease water bills.
- The amount of imported water from outside can be restricted up to the certain limit.
- Stored water can be used anytime in future.
- It improves the quality and quantity of groundwater.
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No skilled labor is required to operate this system.