Why do we need recharge wells for borewell ?

Ground water is a precious gift from nature and we use bore-wells to get it . Most of the countries in the World are overusing its groundwater resources. This leads to the drop in groundwater levels, reduction in or ceasing of borewell discharges, saline intrusions, and deteriorating water quality. Water scarcity directly impacts the social structure of the country and economy of the country. Without groundwater, World would face serious food shortages. So the problem will intensify with the time. The best solutions are, Stop misuse of water , recycling waste water and storing rain water. Groundwater recharge can be achieved through man made recharge structures such as recharge wells , check dams , Rain water harvesting. As an individual, you can start with recharging your borewell via recharge wells . Borewell Recharge through recharge wells helps in control and mitigate flooding and to help ensure rainwater percolates into groundwater. There are two ways to recharge your borewells : direct and Indirect. Direct recharge is recommended only for dry borewell or borewell with very low yields. Indirect recharge is recommended only on well-performing borewells. Direct Recharge – In this method, the filtered rainwater is directly led into the bore well casing pipe. Indirect recharge– Indirect recharge is done via constructing recharge a recharge well within a 5-meter radius of the bore well. A minimum of 1-meter distance to be maintained between the recharge well and the bore well. How to construct recharge well – Recharge wells are of lower depth and radius than conventional open wells, So the construction of recharge well is cheaper and simpler than conventional open wells. The size of recharge wells depends on need. This article explains how a recharge well is built. The steps followed :

• Land excavation: Digging well to the desired depth as suggested by Hydrologist . Depth must be well above the water table. Select land near the borewell , within 5 meter radius of the borewell. Minimum 1meter distance must be maintained between borewell and recharge well. The place must be away from sewage line and away from the foundation of the house. Now after evacuation, you will get a huge amount of mud. this is difficult and expensive especially in the core areas of cities as there is no demand for this mud .Its better to dump it in the area where land of evacuated by other means, but it may still cost money.
• Then we have to place precast RCC rings, the External diameter of the RCC rings should be 15cm-21cms lesser than the diameter of the well. Don’t use plaster to close the gap between two slabs.
• Use jelly to filling the gap between RCC rings and the well. The gap should be filled very tight. Make sure that well wall does not collapse. Then the next step is Slitting of holes into the casing pipe and wrap it with mesh.
• Use manhole covers to cover the pit . To prevent accident a good quality of iron grill or RCC covers. Pack the remainder part of the pit with stones, sand, and jelly.
• Standard Sizes for the recharge well is 90cm width and 600cm depth, to 180cms width 1200 cms depth.

Costing –

• Between INR 9,000-12,000 depending on the diameter and the depth. A recharge well of one meter diameter and six-meter depth has the capacity to store around 5,000 liters water. What it pushes into the ground varies between 2,500 liters and 10,000 liters daily.
• A 3ft diameter and 20ft deep well, can recharge groundwater from nearly 1,000 square metres, which in a year of normal rainfall of about 900 mm means about 1 million litres water. Think about it!
• According to India Water Portal, in Bangalore alone, as much as 3,000 million litres falls daily as rain during the monsoon. On one acre, this works out to roughly 3.6 million litres annually. If the city manages to recharge even 30% of the rainwater it gets, it will have more than what the Cauvery River is supplying current to the city, minus the huge energy bill.