Groundwater Recharge by Percolation Pit

“Before Going to the process point let’s have some review about groundwater”

India is going to face a major water crisis in the future. Overexploitation of groundwater and intensive irrigation in major canal commands has posed a threat to groundwater in India. It has been reported that in many parts of the country the water table is declining at the rate of 1–2 m/year. A few districts in Punjab show substantial decline in groundwater table, with depletion occurring at a rate of 91 cm per year.In Punjab, the districts of Ludhiana, Jalandhar, Kapurthala, Nawashahr, Sangrur, Patiala and Barnala are in the red zone for over-exploitation of groundwater.

Structure of the earth consists of different layers, surface of earth is covered with a soil zone below that weathered zone next to that fractured zone and finally central core of the earth is massive rock zone. Even this massive rock has cracks, the percolated rainwater get stored in all these layers.This storage itself called underground water.Openwell generally of 20ft to 30ft depth depend on the storage water from the soil and weathered zone.The borewell gets water from fractured and rock zone. Water from deep layers of will have more salt content, this hard water is unfit for irrigation and drinking also.

Salt layer accumulates in the irrigation pipe. This saline water decreases the percentage of germination and crop yield. So, recharging water can bring down the salinity of such borewell water. Hence it improves the water yield as well as quality of water. It can be the cheaper and permanent solution of the water problem.

Here is the borewell recharge technique explained:

• Dig a pit of 10x10x10ft keeping borewell casing pipe at the center. At the bottom level of casing pipe, fit a clamp to the casing pipe and put a concrete bed (5 to 6inches) to prevent slipping down of the casing pipe.

• Drill holes on the casing pipe with the help of an electric drilling machine.on a 6ft length of a pipe around 150 holes of 8mm to 10mm size at 3inches gap. It can percolate 10k liters of water per hour.

• Next step is to create filter system. Use good quality aqua and nylon mesh for this purpose.These have anti insect property to protect it from termites Bind the pipe tightly with nylon mesh and followed by aqua mesh and tight with aluminum wire. Next layer is the nylon mesh and tight with wire. Create a sand layer of 1 inch between these two mesh layers.

• Next step is filling percolation pit. Put a bigger stone of 1ft to 1.5ft size to a height of 5ft, use hard stones. Then, fill with granite jelly of 4inch to 5inch size to a height of 1ft. Next 40mm jelly layer of 0.5ft. Above that is a layer of 20mm jelly of 0.5ft.

• If it is a drinking water borewell put a charcoal which prevents bad odour of the water and not required for the irrigation.
• After jelly layers put a layer of HDPE net of good quality. It avoids sand and soil entering into the lower layers.Then put a layer of clean and thick sand to a height of 2ft.It completes the filtering system of the percolation pit.

• Construct a wall around the percolation pit and retain a single entry point for the water, which prevents silt accumulation.

• This completes the percolation pit design.
• And should connect the percolation pit to farm ponds through the pipeline channels. Where you need to harvest and store rainwater in a farm pond to recharge the groundwater through percolation pit

Advantages of tube well percolation pit:

• Implementation of the technique shows a 3–6 times increase in the tube-well’s water-output.
• Quality of the water is increased.
• It is a cost effective technique, use of only natural materials helps keep the cost much lower (Rs 30,000/-) compared to the cost of getting a new tube-well (Rs 1,50,000/-) .
• It is a permanent solution to water-scarcity issues faced by farmers.

Let’s see a video on how to conserve and recharge our valuable groundwater. http://bit.ly/waterrechargeindia

Eco-friendly water conservation improves ground water level. Let’s start initiating this technique where we can overcome water crisis in the world.

Reference: http://bit.ly/savewaterindia