Ground water recharging

                                                     By rain water harvesting and recharging pit

            Now a days, water scarcity is one of the major issue. And to fight with this problem we have to come together and giving technical solutions on this.

·       Introduction

                  Recharging pit is one the economical and feasible method of ground water recharging. Water is collected from the roof and allow to flow through the pipe (dia. 90mm) upto the recharge pit. Pit is made of such material which having high permeability (generally gravell of large size used at bottom and fine aggregates used at top), so water can percolate with high rate.

  

·       Advantages

1.       In 1000 sq feet area, per 100 c m rain about 1,00,000 liters of water recharge the ground water.

2.       If the water is converted in runoff the it can produces the problem of city road flooding, some time minor flood.

3.       Helps to maintained the water level in well, tubewell, in summer.

4.       Increases soil fertility.

5.       Reduces the chance of drought. And many more…..

·       Locality

            If the pit aims to recharge a borewell, it should be built as close to it as possible. Ideally it should be in the valley of the surface layout. Or it can be constructed anywhere away from any water pollution source.

  

·       Site identification

                  The site should have a sufficient clean and large catchment. It should also permit fast infiltration and percolation. And geological condition also supports the water percolation. Many factors affect the suitability of a site as an infiltration facility for the disposal of recharge pit. Among these, the following are most important : depth to groundwater, surface and underlying soil type.

·       Conveyance pipe

              Pipe is made up of chemically inert material like p v c. and of sufficient size to carry the water as per roof size. Proper arrangement should me made at inlet so the solid impurities can be filtered out at inlet.

·       Excavation

             The excavation should reach porous soil / weathered rock / fracture. Generally it happens from 6 to 8 feet deep. The diameter of the pit will depend on the catchment area and  the rate of percolation of the soil... It can vary between half a meter to 3 mete.

·       Filling of the pit

                    You need gravel of different sizes and sand for the top of the pit. The big gravel at the bottom. The smaller ones on the top of it will support the layer of sand. A mesh between the sand and the gravel will prevent the sand to escape below. Instead of the sand, you can put a layer of soil (leaves or planted earth). These materials will also filter the water. A supporting wall is made to reduce erosion of material. Splash pad is made for prevention of sand /soil erosion due to water pressure.

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  Finished recharge pit

 Final finish the pit for good ashtetic. It will look like the normal surface of the ground.