Nature replenishes the Groundwater Resource annually through seasonal rainfall, by way of infiltration through soil layers. Due to urbanisation, the soil surface exposed to the recharge gets drastically reduced and therefore natural recharge gets diminished. Groundwater resources have already been extensively developed and therefore any further indiscriminate development should not take place. Groundwater resource as a natural resource has the major benefit in meeting the emergency supplies during the water scarcity periods. In order to maintain the groundwater resource potential, a hydraulic equilibrium must be made between the availability and utilization. Measures dovetailing rainwater harvesting and artificial recharge will augment the groundwater resource.
At this juncture, measures are to be taken up by various Governmental and non-Governmental organisations as well as the public at large, so as to harvest the rainfall and maintain groundwater balance. Such measures will help to have reliable and sustainable groundwater resource for supplementing the domestic and industrial water supply needs of urban area.
Artificial recharge may be defined as the process of augmenting the natural infiltration of rain water or surface run off into the underground formation by some artificial methods. The methods suggested are water spreading, recharge through pits, trenches, and bore wells, shafts and directly diverting run off water into the existing wells. The choice and effectiveness of any particular method is governed by local hydrogeological and soil conditions and ultimate water use.
Availability of rainwater from rooftop is so high in the urban areas and if properly diverted and used, artificial recharge will not only increase the groundwater availability, but also help in reducing the water scarcity problem of cities and towns.
Commonly run off water from rooftop are let off into the drains. Instead of this, the outlets can be connected through a pipe to a storage tank and let into gravel filled trenches, pits or existing open wells/bore wells etc., to serve as recharge points.
This method is less expensive and very effective and if implemented in good spirit by each buildings/housing society & factories will help in augmenting the groundwater availability of the area.
- Provides self-sufficiency to your water supply.
- Reduces the cost of pumping of ground water
- Provides high quality water, soft and low in minerals.
- Improves the quality of ground water through dilution when recharged to ground water.
- Reduces soil erosion in urban areas.
- The roof top rainwater harvesting is less expensive.
- Rainwater harvesting systems are simple which individuals can adopt.
- Rooftop Rain Water harvesting systems are easy to construct, operate and maintain.
- In hilly terrains, rainwater harvesting is preferred.
- In saline or coastal areas, rainwater provides good quality water and when recharged to ground water it reduces salinity and also helps in maintaining balance between the fresh-saline water interface.
- In Islands, due to limited extent of fresh water aquifers, Rainwater harvesting is the most preferred source of water for domestic use.
- In desert, where rainfall is low, rainwater harvesting has been providing relief to people.
- Utilisation of dried up well
- Decentralised percolation through water spreading and longitudinal trenches.
- Centralised percolation through pits.
- Recharge through shafts.
- Recharge through Wells