14
An Innovative Soak Pit Technique
A Best Practice to Recharge Thousands of Drinking and Irrigated Bore Wells
(A case study form the border villages in Chitradurga and Davanagere districts of Karnataka State)
It is quite normal that in water stress drought areas, where the water becomes a scarce item some creative farmers, try to use different new survival techniques as a coping strategy to conserve and manage the limited water resources.
Mr. Devarajulu Reddy belonging to Chitradurga district started designing this innovative technology by constantly making some improvements or modifications to the conventional soak pit model when he realized practically after drilling up to the level of 1000 ft to 1500 ft of depth in search of ground water. He realized in the year 1996 that recharging of the wells with rain water is the only solution to get water in future. He started assisting the farmers with his new technique since then. Initially there was no encouragement to his technique. But now thousands of farmers are following him.
Mr. Ravi, a progressive farmer, belonging to Alligere village, ( which is located 15 K.ms away from Davanegere town, Davanagere district of Karnataka state) got fed up, by spending lakhs of rupees on deepening as well as drilling the new bore wells in his fields. Because, there was no increase in the quantity of water where as his debts were increasing very fast. As a result he was in deep confusion about the very future of his agriculture occupation. At that frustrating movement in the year 2002, he was advised by Mr. Devaraju Reddy, to adopt his innovative soak pit technique to recharge the bore well in the rainy season. As a last way out he successfully adopted the technology to his bore wells. Now he is very happy because the borewells got recharged and he is able to take two Irrigated- Dry (I.D) crops in a year in his 4 acres of land. The water level is stabilized in his bore wells irrespective of continuous droughts for the past 4 years. The water level is gradually increasing by 10-12 feet every year in his wells. He is harvesting the rain water from 6.5 acres of land which is located in the upper region of the bore well. Realizing the importance of water he is conserving the water efficiently.
Mr. Ramadas another farmer belonging to another village by name Hadadi village of Davanegere taluk and Mr. Veerabhadrappa, who resides in a village by name Bijikere, Molakalmuru taluk of Chitradurga district, have also adopted this technology. Now thousands of farmers are trying to follow this technique. So far about 1000 borewells in Chitradurga and 4000 borewells davanagere district of Karnata are being recharged with this technology.
At present the Karnatake government is assisting the farmers to install the soak pits by using the Food for Work Programmes.
In the above mentioned areas this innovative soak pit model has given wonderful results not only to the irrigation water sources but also to the drinking water sources.
Conclusion:
National Rural Employment Guarantee Scheme (NREGS) can be used to assist lakhs of farmers to install the soak pits: Best solution to sustain our ground water sources also.
Andhra Pradesh Government can assist lakhs of poor farmers to install the soak pits to recharge their borewells by using the NREGS. The advantage is that the entire work of Installation of soak pits is labour intensive activity. Hence it is very easy to include this activity under the NREGS.
Enclosures:
1) Techniques followed to install the Soak Pits
2) Budget Estimation ( It was prepared in the year 2004 hence it should be revised)
3) Sketches of the Soak Pit
4) Photographs
Mass Education, R.K. Nagar, Anantapur-515 004, Andhra Pradesh, India
Phone: 08554-232643, Cell: 94405 47202
THE TECHNIQUES FOLLOWED TO GET GOOD RESULTS
WHILE INSTALLING THE SOAK PITS.
Selection of Bore Wells:
Caution in the selection wells:
Ø The soak pits should not be created for the wells which have failed to yield water at the time of drilling.)
Ø Select only such dried up or drying wells to which there is a good Catchment area at their upper region to harvest the rain water.
Ø As far as the Hand Pump is concerned the soak pits were dug adjacent to them and for the bore wells connected to the Drinking water Schemes are concerned the soak pits were created around them to get good results.
Size of the Soak Pits:
i) Hand Pump: Length: 4.0 m x Breadth: 2.0 m x Depth: 3.0 m
ii) Pipe line Water Scheme Bore Well: 3.0m x 3.0m x 3.0m
Filling up of the Soak Pits (shown in the picture No.3):
The soak pits were filled with three sizes of stones (30-40cms, 15-20cms, and 40mm) and coarse sand. 30-40 cms size stone was filled up to 6 ft, 15-20 cms size stone was filled for 2 ft feet, 40mm size stone was filled for one feet and sand for the remaining one feet.
Separation of the stones and sand (shown in the picture No: 3):
A strong nylon net was laid in the soak pit to separate the stones from the sand. If not separated the sand and mud will penetrate between the stones and close the vacant places between the stones gradually.
Replacement of the sand every year:
The sand is being replaced once a year because the rain water brings nice mud which can reduce the water infiltration rate through the sand.
Cement Platform at the bottom of the casing Pipe of the Bore Well (shown in the picture No: 1):
After digging the pit around the bore well there is a chance that the casing pipe might slip into the bore well. To avoid this danger cement concrete should be laid around the casing pipe at the bottom of it.
A clamp on the cement plat farm (shown in the picture No.1):
A clamp should be fixed in the cement concrete at the bottom of the soak pit so that the casing pipe is not loosened and fell down into the well.
Holes to the Casing Pipe (shown in the picture No.2):
4 mm to 6mm holes were made with a drilling machine to the casing pipe.
The distance between the holes:
The distance between the holes is around 4inches.
No of holes to be made: 300 to 400
Covering the holes with mesh (shown in the picture No.2):
The holes made to the casing pipe were covered firstly with Nylon mesh and later on aksha mesh was covered and tightly tied to prevent the mud and dust through these holes.
Fill up the pit with material carefully:
The stones and other material were put down or arranged carefully around the casing pipe to avoid damage or its breakage.
Protection wall around the soak pit:
A protection wall (with bricks) with small inlets was built around the soak pit with an height of one foot to protect the soak pit from the force of the run-off rate of rain water and also to increase the infiltration of rain water into the pit.
Silt Trap:
A silt trap was created at the entrance of the rain water in the soak pit.
Formation of the bund across the slope behind the H.P or bore well:
An earthen bund was formed behind the well by using the dug out soil to harvest the rain water.
Increase in the water yield: For Example:
If the Area Of catchment is: 100 Sq.m
Average Annual Rain fall or Height of the Rain fall is: 500 mm or 0.5 mtrs
The total Volume of the rain fall over the catchment area is: 100Sq.m x 0.5 m = 50 cu.m or 50,000 ltrs (1.cu.m =1000ltrs)
If the catchment area is one acre and the average annual rain fall is 500 mm The total volume of the rainfall over the catchment area is: 1.00 acre x 0.5= 0.5 acre mtrs.
20 lakh liters of water per year if the annual average rainfall is 600 mm
The increase in the yield depends upon the catchment area above the borewell. For every acre of catchment 20 lakh liters of water would be available if the average rainfall is about 500 mm.
ANNEXURE – 1
DETAILED BUDGET ESTIMATION FOR THE CONSTRUCTION OF A SOAK PIT
Around the Pipe line Drinking Water well
(Size 3.0m x 3.0m x3.0)
(As per SSR 2004-05)
Sl.No. / Particulars / No. / Length(mts) / Breadth
(mts) / Depth
(mts) / Quantity
Cums / Rate per Cums / Total Amount
Rs
1 / Earth work for Soak pit digging
a) For Soak pit digging in Hard Grave Soil / 1X1 / 3.00 / 3.00 / 1.00 / 9.00 / 30 / 270
1X1 / 3.00 / 3.00 / 1.00 / 9.00 / 41 / 369
1X1 / 3.00 / 3.00 / 1.00 / 9.00 / 52 / 468
b) Side wall / 1x2 / 3.00 / 0.30 / 0.30 / 0.54 / 26 / 14
1x2 / 3.00 / 0.30 / 0.30 / 0.54 / 26 / 14
2 / Bund formation and sectioning across the slope adjacent to the bore well. / 12 trips / 105/- per trip / 1260
3. / Labour Charges for laying of CC 1:6:10 / 1x2 / 3.00 / 0.30 / 0.30 / 0.54 / 150 / 81
1x2 / 3.00 / 0.30 / 0.30 / 0.54 / 150 / 81
Brick Masonry / 12.00 / 0.225 / 0.30 / 0.81 / 150 / 122
Plastering / 12.00 / 0.80 / - / 9.6 Sq.mts / 16/- per sq m / 154
4 / Cost of Cement / 5 bags / 140/- per each bag / 700
5 / Cost of Bricks / 400 / 1.25/- per each brick / 500
6 / Cost of stones and sand its Conveyance
i) Rough Stones (30cm-40cm) in Total Qty 50% / 4 trips / 9.00 / 230/- per trip / 920
ii) Small rough Stones (15cm-20mm) in Total Qty 25% / 4 trips / 9.00 / 230/- per trip / 920
iii) 40mm size metel stones / 2 trips / 4.50 / 655/- per trip / 1310
iv) Sand Qty 25% / 2 trips / 4.50 / 180/- per trip / 360
7 / Transportation of Cement and bricks / 1 trip / 255/- per trip / 255
8 / Filling of the Stones and sand into the soak pit / 12/-Person
days / - / - / - / 50/- per Person
day / 600
9. / Cost of Mesh, Clamp and Labour charge for the fitting of the casing pipe / 1500
10 / Photos and Documentation / 200
11 / Add 2% on total estimate cost for P.S and contingencies / 202
Total / 10300
ANNEXURE – 2 Sketches of the Soak Pit
ANNEXURE – 3
Photographs of the recharge Bore Well