Now that rainwater harvesting has become mandatory in Bangalore, this is the time to dig recharge wells. The law states that the depths should be a minimum of 10 feet. In most parts of the city, a depth of 20 feet to 30 feet is recommended.
All individual households, apartments, layouts, industries and institutions can construct recharge wells and should appropriately include it as part of the design itself. In many cases the groundwater levels increase almost immediately after a rainfall year and this water is available for supplementary and appropriate use. In many cases borewells too are benefited as the shallow aquifer eventually recharges the secondary porosity from where borewells draw water.
A typical recharge well is one meter in diameter. It is then lined with pre-cast concrete rings with perforations to allow water to slip out from the sides. These rings are then gradually lowered into the well to line it from the bottom all the way to the ground level and above. A solid cover of steel or pre-cast concrete rings is placed on the top for security and safety purpose. This is very important.
The capacity of such a recharge well of one meter diameter and six meters depth is about 5,000 liters. Normal procedures for well maintenance, such as regular cleaning and disinfection annually, are recommended. Removal of silt regularly helps in greater recharge. By integrating rainwater harvesting with groundwater recharge each citizen can contribute to the cause by using water judiciously and ensure its continued availability for future.
Source: The Hindu
