NAbard Model Bank Projects

Minor Irrigation Drip Irrigation

1.0 IntroductionDrip irrigation, also known as "trickle" irrigation, is one of the methods of water management. Under this system, water is carried to the plant under low pressure, through small diameter plastic pipes and delivered at the root zone, drop by drop through drippers. Drip irrigation is widely practised and established method of irrigation in developed countries and is slowly gaining popularity in India. It is most suited for horticulture crops, vegetables etc. and finds applicability in hard rock areas where groundwater is scarce and helps in optimisation of the limited water resources. The system has its advantages and limitations. Its advantages are in terms of savings of water (50-60%) of that required for flow irrigation, effective use of fertilizers, less labour and energy cost. The limitation for adopting of this method is its high initial cost which is beyond the purchasing capacity of small and marginal farmers and thus mainly adopted by large farmers.As a policy to encourage use of such systems, the Govt. of India announced the Centrally sponsored Micro Irrigation Scheme during 2005-06. The total cost of the scheme is being shared between Central Government, the State Government and the beneficiary either through his/her own resources or soft loan from financial institutions in the ratio of 40%, 10% and 50% respectively. Bankable schemes have to be formulated for availing bank loans. This model gives broad guidelines for scheme formulation by banks for financing drip irrigation systems.

2.0 SCHEME REQUIREMENTSScheme formulation for installation of drip irrigation systems against bank loan requires both technical and financial details. This should briefly give the command area, type of plant/tree, required spacing between plants, land scope etc. and general topographic features. The important items that should be included in a scheme for drip irrigation system are given bellow :

2.1 SoilThe general nature of the soil and its characteristics should be indicated. Soils have a bearing on the water requirements of crops and setting up the irrigation schedule. A drip system is not suitable for clayey or gravely soils as would be seen from table 4. Best results with this system are obtained with medium textured soils.

2.2 Climate and RainfallThe climatic condition and rainfall of the area governs the irrigation requirements of the crops. The evapo - transpiration data is also important. The normal monthly evaporation data as per Indian Meteorological Department (IMD) should necessarily be given which would greatly help in determining the daily water requirements and irrigation needs in different seasons.

2.3 Groundwater qualityGroundwater quality in the scheme area should be given. Its suitability for irrigation may be

indicated in sodium absorption ratio, total dissolved solids etc.

2.4 Designs of Drip SystemThe designs of the drip system especially the layout, size and length of mains, sub-mains, laterals etc. based on land slope and field plot layout should be given in the scheme.

Emitter selection, number of emitters to the plant, water discharge through the emitter and total pumping schedule should be indicated.

2.5 Well CapacityThe source of water should be indicated. If the source of water is a groundwater structure, the diameter, depth and well yield together with HP of the pump set already installed may be given. This is necessary to decide the discharge available from the well and its optimum utilisation.

2.6 Economics The economics of investment should be given in detail to justify the loan. The scheme should also give details about repayment period, rate of interest, subsidy available etc.

2.7 Basic Data Information A drip irrigation system requires certain basic data information to plan its layout and ensure trouble free operation. A format for the required information is given in the Annexure I which necessarily should be provided in the scheme.

3.0 TECHNICAL ASPECTS3.1 Design ParametersThe design of a drip Irrigation system involves estimation of the following parameters.

1. Area to be irrigated, type of plants, their spacing and numbers per hectare.2. Peak water requirement of a plant per day. For estimation of total water requirement for a

given area, the number of emitters required per plant, amount of water discharged per hour through each emitter and the total number of hours water is available should be known/estimated.

3. Design of Main and Lateral Drip Lines. This depends upon friction head loss which in turn is governed by the type of plantation/crop and field configuration.

4. Water required to be pumped from the well. This depends upon hydrogeological conditions in the area and water requirement of plants/crop.

5. Horse Power of Pump set depends upon discharge and total head including friction losses over which water is to be lifted/pumped.

6. Unit cost.

3.1.1 Command AreaA command area map giving systems layout is necessary to plan and design a drip irrigation system. It may not be necessary to have a detailed contour plan but it is helpful if a plan showing the highest and lowest points along with well location is given in the scheme. This enables

proper design of main line and laterals to suit the spacing and number of plants.The recommended spacing and population of some of the important plants/crops are given in the Table 1 below.

Table 1 : Spacing and Plant Population of Important Plants/Crops

Sr.No Crop Spacing (m) Plant Population (Nos/ha)

1 Grapes 3.0x3.0 1,100

2 Mango 10.0x10.0 100

3 Oranges 5.0x5.0 400

4 Lime 6.0x6.0 270

5 Coconut 7.5x7.5 175

6 Banana 1.5x1.5 4,400

7 Cotton 1.3x1.3 5,900

8 Tomato/Brinjal 1.0x0.5 20,000

9 Sugarcane 1.0x0.3 33,000

10 Litchi 6.0x8.0 208

3.1.2 Water Requirement of crops/plantsWater requirement of crops (WR) is a function of surface area covered by plants, evaporation rate and infiltration capacity of soil. At first, the irrigation water requirement has to be calculated for each plant and thereafter for the whole plot based on plant population for the different seasons. The maximum discharge required during any one of the three seasons is adopted for design purposes.The daily water requirement for fully grown plants can be calculated as under.WR = A X B X C X D X E.................Equation (1)Where : WR = Water requirement (lpd/plant)A = Open Pan evaporation (mm/day)B = Pan factor (0.7)C = Spacing of crops/plant (m2)D = Crop factor (factor depends on plant growth for fully grown plants = 1)E = Wetted Area (0.3 for widely spaced crops and 0.7 for closely. spaced crops)The total water requirement of the farm plot would be WR x No.of PlantsThe daily water requirement pf various crops per plant for different pan evaporation readings are given in Table 2.

Table 2 : Water requirement of Crops/Plants on the Basis of Pan Evaporation Data

Crops Spacing(m)

Pan Evaporation ( mm/day )

2 4 6 8 10

Water Requirement( lpd /plant)

Grapes 3.0x3.0 3.7 7.6 11.3 15.1 18.9

Mango/Sapota 10.0x10.0 42 '84.0 '126.0 '168.0 '210.0

Oranges '5.0x5.0 10.5 '21.0 31.5 '42.0 52.5

Coconut 6.0x6.0 15.1 30.2 45.4 60.5 75.6

Banana 7.5x7.5 24.2 48.5 72.8 '97.0 121.3

Cotton 1.5x1.5 1.7 4.4 6.6 8.8 '11.0

Tomato/Brinjal/Chillies 1.3x1.3 '0.5 3.3 '5.0 6.6 8.3

Sugarcane 1.0x0.3 '0.3 '1.0 2.5 '2.0 2.5

Litchi 6.0x8.0 35 42 65 69

The water requirement for different seasons can be calculated using Equation 1 given above. The maximum discharge required during any one of the three seasons is adopted for design purposes

3.1.3 Design and Performance of emitterThe design, number of emitters required for plant and their discharge are important factors in designing a drip irrigation system. Various emitters are designed for controlled release of water to the plants. It is necessary for manufactures of drip system to state optimum operating pressure and discharge and the emitter is so selected that application rate equals to the absorption rate of soil so that no water stagnation takes place on the surface of the soil. In some systems a short length of flexible plastic tubing of small diameter is used as emitter. This tubing is generally of 0.96mm diameter and is inserted through holes in walls of the laterals. This is commonly known as micro tube system. The flow from different lengths of 0.96mm polyethylene tubing under various pressure is given in Table 3.

Table 3 : Flow from polythelene Tube emitters of 0.96 mm diameter(lph)

Length of tubing Pressure in supply line (Atmosphere)

(mm) 0.1 0.2 0.3 0.5 0.75 1 1.5

7.5 6.1 10.4 13.9 20.2 27.2 33.2 44.7

15.5 4.1 6.7 9 12.8 17 20.7 27.4

25 2.9 4.7 6.3 8.9 11.8 14.4 19

35 2.3 3.7 4.9 7 9.3 11.3 15

50 1.8 2.9 3.8 5.5 7.3 8.8 11.7

75.5 1.4 2.2 2.9 4.2 5.6 6.8 9

100 1.1 1.8 2.4 3.4 4.5 5.5 7.3

125 0.96 1.6 2 2.9 3.9 4.7 6.3

150 0.84 1.4 1.8 2.6 3.4 4.2 5.5

175 0.75 1.2 1.6 2.3 3 3.7 4.9

200 0.69 1.1 1.5 2.1 2.7 3.3 4.4

250 0.6 0.97 1.3 1.8 2.4 2.9 3.8

300 0.53 0.85 1.1 1.6 2.1 2.6 3.4

Another method of releasing water from laterals is through small perforations in the walls which are sometimes called "soakers".

3.1.4 Performance of EmitterWater from emitters fall on ground and is absorbed by soil. The wetted area depends upon the soil type and rate at which water comes out of emitters. The infiltration rate for various types of soil and the surface area wetted due to drippers at various flow rates are given in Table 4&5.

In orchards having widely spaced plants, two or more line of laterals may be required for each row. Sometimes a loop with 3 to 4 emitters is placed around each plant to provide the required wetted area. This should be away from the plant stem.

Table – 4 : Infiltration Rate of Soil

Sr.No. Texture Infiltration Rate (cm/hr)

1 Coarse Sand 2.0 to 2.5

2 Find Sand 1.2 to 2.0

3 Fine Sandy loam 1.2

4 Silty loam '1.0

5 clay loam 0.8

6 clay 0.5

Table – 5 : Surface Area Flooded by Emitters

Sr.No. Emitter flow Soil infiltration rate (Cm/hr)

Rate (lph) 0.25 0.5 0.75 '1.0 1.25 '1.50

Wetted Area (sqm)

1 '1.0 0.4 0.2 0.13 0.1 0.08 0.07

2 '2.0 0.8 0.4 0.27 0.2 0.16 0.13

3 '3.0 1.2 0.6 '0.40 0.3 0.24 '0.20

4 '4.0 1.6 0.8 0.53 0.4 0.32 0.27

5 '5.0 '1.0 '1.0 0.67 0.5 '0.40 0.33

6 '6.0 1.2 1.2 '0.80 0.6 0.48 0.4

7 '7.0 1.4 1.4 0.93 0.7 0.56 0.47

8 '8.0 1.6 1.6 1.07 0.8 0.64 0.53

3.1.5 No. of emittersThe number of emitters is based on the volume of wetting for each plant. Generally, 30-70 percent of the area is wetted dependent upon plant spacing, nature & development of root zone. The number of emitters required per plant is estimated as the ratio of rate of irrigation requirement to the emitter discharge. If single emitter is provided, it must be placed 15-30 cm. from the base of the plant.

4.0 LAYOUT OF DRIP SYSTEMThe main Line in a drip system should follow land contour as closely as possible. If there is a slope, should be made for pressure differences due to change in elevation. A fall of 1 m in elevation is equivalent to an increase in pressure of about 0.1 atmosphere. Where main lines are laid down on a slope, the increase in pressure due to elevation change may partly compensate the friction head loss. To provide nearly uniform pressure at each emitter, the tubing should be of sufficient diameter to avoid excess friction losses. The water delivered in the supply line is released through emitters spaced along the supply line. The total friction head loss due to lateral openings can be calculated by multiplying the head loss over the total length by a Reduction Co-efficient given in Table 6. However, the additional head loss on account of diversion of flow from the main/laterals into the emitters has to be separately added while estimating the total head for purpose of calculating hp of the pump set. Friction head loss for various flow rates in plastic tubing of different sizes are given in Table 7.

The allowable pressure drop in mainline and laterals depend upon the operating pressure required at emitters. The pressure difference between the proximate and distant point along the supply line should not exceed 20% which will keep the variation of discharge within 10% of its value at the first emitter.

Table - 6 Reduction Co-efficient 'F' for Multiple Outlet Pipeline Friction Loss Co-efficient

No.of outlets F No of outlets F

1 1 8 0.42

2 0.65 10 to 11 0.41

3 0.55 12 to 15 '0.40

4 '0.50 16 to 20 0.39

5 0.47 21 to 30 0.38

6 0.45 21 to 37 0.37

7 0.44 38 to 70 0.36

Table - 7 Friction Head Loss in Meters per 100 m. Pipe Length

Flow(lph)

Inside diameter (mm)

9.2 11.7 12.7 13.9 15.8 '18.0 '19.0

Head loss in meters per 100 m length of pipe

200 10.2 5.2 2.5 1.7 0.8 0.4 0.3

400 '39.0 '18.0 8.6 5.7 2.7 1.6 1.1

600 -- '39.0 '18.0 '13.0 5.9 3.2 2.5

800 -- -- '30.0 '21.0 '10.0 5.5 4.1

1,000 -- -- '45.0 '30.0 16 8.3 6.2

1,200 -- -- -- '42.0 '21.0 '11.0 8.8

1,400 -- -- -- '56.0 '28.0 '16.0 '11.0

1,600 -- -- -- -- '36.0 '20.0 '15.0

1,800 -- -- -- -- '45.0 25 '19.0

2,000 -- -- -- -- '54.0 '30.0 '23.0

4.1 MainlineTo design the main line, the pressure required at proximate end of laterals and the maximum friction loss at that point should first be determined. Friction losses due to valves, risers, connectors, etc., should be added to this. Sometimes, two or more laterals simultaneously operate from the mainline and these have to be properly accounted for in the design.The friction head loss in mains can be estimated by Hazen-Williams formula is given bellow.hf = 10.68x(Q/C) xD x(L+Le)Where : hf = Friction head loss in pipe (m)Q = Discharge (M /sec)

C = Hazen Willian constant (140 for PVC pipe) D = Inner dia of pipe (m)L = Length of Pipe (m)Le = Equivalent length of pipe and accessories

4.2 LateralsThe design of lateral pipe involves selection of required pipe size for a given length to meet the required quantity of water to the plant. This is the most important component of the system as large amount of pipe per unit of land is required and the pipe cost is such that system is economically viable.In designing the lateral, the discharge and operating pressure at emitters are required to be known and accordingly, the allowable head can be determined by the same formula as the main line.

4.3 Design CriteriaThe pressure head of emitter of any lateral should be calculated based on discharge requirement of each emitter.

1. It should be ensured that the head loss in the lateral length between the first and last emitter is within 10% of the head available at the first emitter.

2. The friction head loss in the mainline should not exceed 1m/100m length of the mainline.

Friction head loss for various discharges is given in table 8 and equivalent lengths of straight pipe in meters giving equivalent resistance to flow in pipe fittings in Table 9.

Table-8 : Friction Losses for Flow of Water (m/100m) in smooth Pipes(c=140)

Discharge(lps)

Bore diameter (mm)

20 25 32 40 50 65 80 100 125 150

0.5 16.4 5.5 1.6 0.56 - - - - - -

1 - 10 6 2 0.68 - - - - -

1.5 - - 12.7 4.3 1.45 0.4 - - - -

2 - - 16 7.3 2.5 0.68 0.25 - - -

3 - - - 15.5 5.2 1.45 0.53 - - -

4 - - - 26.4 6.9 2.5 0.9 0.3 - -

5 - - - - 13.4 3.8 1.36 0.46 - -

6 - - - - 18.8 5.2 1.9 0.64 0.22 -

7 - - - - - 6.9 2.5 0.84 0.29 -

8 - - - - - 8.9 3.2 1.1 0.37 0.15

9 - - - - - 11.1 4 1.36 0.46 0.19

10 - - - - - 13.4 4.9 1.65 0.55 0.32

For other type of pipes (new) multiply foregoing figures by factor given below

Sr no Particulars C Multiplication factor

1 Galvanised iron 120 1.33

2 Uncoated cast iron 125 1.23

3 Coated cast iron, Wrought iron coated steel 130 1.07

4 Coated spun iron 135 1.07

5 Uncoated Asbestos cement and concoated steel pipes

140 1

6 Coated asbestos cement spun concrete or bitumem lines

145 0.94

7 Smooth pipes ( lead, brass, copper, stainless steel, glass, PVC

150 0.86

Table - 9 : Length of Straight Pipe in Meter giving Equivalent Resistance to Flow in Pipe Fittings [ IS : 2951 ( Part II ) - 1965 ] (Equivalent Length in Mtrs.)

Sr. No.

Pipe size (mm)

Elbow Bend 90 Bend Standard Tee Sluice valve Foot or Reflux valve

(Ks=0.7) (ks=0.12) (Ks=0.4) (Ks=0.4) (Ks=3.5)

1 25 '0.536 '0.396 '0.704 '0.077 '2.04

2 40 '0.997 '0.569 '1.131 '0.142 '3.05

3 50 '1.296 '0.741 '1.704 '0.185 '3.96

4 65 '1.814 '1.037 '2.384 '0.259 '5.18

5 80 '2.241 '1.281 '2.946 '0.320 '6.10

6 100 '2.959 '1.691 '3.889 '0.422 '8.23

7 125 '4.037 '2.307 '5.306 '0.576 '10.0

8 150 '5.125 '2.928 '6.735 '0.732 '12.0

5.0 UNIT COST The unit cost of Drip Irrigation system depends upon the shape and size of command area,

spacing and number of plants and their water requirement. The unit cost should include the cost of following main items.

1. Mainline/Submain 2. Laterals

3. Drippers/micro-tubes

4. Lateral connectors

5. Straight connectors

6. Filters (Screen or Gravel)

7. Bends/end plugs, couplers, joint, tees

8. Pressure gauge, water meters

9. Water regulators

10. Installation charges

The average unit costs of drip irrigation system for different crops are given in Table-10. This is for guidance only.

Table - 10 Unit Cost of Drip Irrigation System

Sr.No. Crop Spacing (m) Cost (Rs/ha)

1 Coconut 8x8 23790/-

2 Sapota/Mango 10x10 17030/-

3 Oranges/Guava 6x6 28010/-

4 Pomegranate 4.5x2.7 32010/-

5 Grapes 2.7x1.8 54370/-

6 Banana/ Papaya 1.8x1.5 73010/-

7 Sugar Cane [(0.75m+1.25m) x 0.15m] lateral spacing-2.25m 60440/-

8 Vegetables 0.6x0.45 103020/-

9 Mango 5x5 32060/-

10 Litchi 6x8 42000/-

The Estimated cost of drip irrigation system for Litchi cultivation on 1 ha plot is given in Annexure-I

6.0 Lending terms & Conditions

6.1 Margin Money : The beneficiaries may contribute towards down payment/margin money ranging from 5 to 25% depending upon their category, i.e., small and other farmers in accordance with the NABARD’s norms. Beneficiary’s own labour can also be taken as his contribution towards the margin money requirement.

6.2 Security : As per RBI norms.

6.3 Interest Rate : The rate of interest to be charged to the ultimate borrowers would be decided by the financing banks as per the RBI guidelines from time to time. However, for working out the financial viability and bankability of the model project, the rate of interest is assumed as 12%.

6.4 Repayment Period : Gestation period can be considered while fixing the repayment period. The repayment of interest shall commence from the end of the Gestation period onwards and would continue till the entire principal and interest thereon is repayed.

Appendix : IIMODEL FOR A SCHEME OF DRIP IRRIGATION This model scheme for drip irrigation system to avail loan assistance give details about estimation of water requirement of plantation crops, system design, HP of pumping unit, unit cost and financial viability of the investment. Let us assume that the beneficiary has an open well of 4m dia and 25 m depth fitted with 5 HP electric pump set. The area has a land slope of 0.5m/100m and the soil is clayey loam. The farmer proposes to install drip irrigation system for a new citrus plantation on a 1ha plot.

a. Design parameters Scheme formulation for installation of drip irrigation system against bank loan requires both technical and financial details. The important items that should be included in a scheme for drip irrigation system are given bellow :

b. Command area A command area map giving systems layout is necessary to plan and design a drip irrigation system. It may not be necessary to have a detailed contour plan but it is helpful if a plan showing the highest and lowest points along with well location is given in the scheme. This enables proper design of main line and laterals to suit the spacing and number of plants.

The present scheme is prepared for application of drip irrigation on one hectare farm of Litchi.

c. Spacing and Plant Population of Litchi in one ha. The No of plants required for cultivation of 1 ha litchi with above spacing would be 100m x 100m /6 m x 8 m = 208 plants. However, the plant spacing adopted by earlier farmers was planting at 8x8m to 12x12m.

d. Water requirement for litchi plants. Water requirement for litchi crop (WR) is a function of surface area covered by plants, evaporation rate and infiltration capacity of soil. The irrigation water requirement for each plant has been calculated for each plant and thereafter for the whole plot of 1 ha based on plant population for the different seasons. The maximum discharge required during any one of the three seasons is adopted for design purposes.

The daily water requirement for fully grown plants can be calculated as under. WR = A X B X C X D X E .................Equation (1) Where : WR = Water requirement (lpd /plant) A = Open Pan evaporation (mm/day) B = Pan factor (0.7) C = Spacing of plant (m2) D = Crop factor (factor depends on plant growth for fully grown plants = 1) E = Wetted Area (0.3 for widely spaced crops )

The total water requirement of the farm plot would be WR x No.of Plants .

e. Estimation of Water Requirement The irrigation water requirement is determined using IMD pan evaporation data. The average season wise pan evaporation data for the area is given below.

S.No. Season Days (Nos)

Total Pan (evaporation during the season (mm)

Avg. Daily Pan Evaporation (mm/day)

1 Kharif (15/6 to 15/10) 122 506.30 4.15

2 Rabi (16/10 to 15/4) 183 649.65 3.55

3 Summer (16/4 to 14/6) 60 408.00 6.45

The daily water requirement of plants using above equation has been worked out as under.

Sr.No Season Evaporation (mm/day) Water requirement

Lpd /plant M3/ day/ha

1 Kharif 4.15 41.83 8.31

2 Rabi 3.55 35.78 7.44

3 Summer 6.45 65.07 13.53

Therefore, the drip irrigation system has to be designed for the maximum requirement of 65.07 litre /day/plant during the summer season and for this the water required would be 13.53 m3/ day/ha of plantation. If the average working hour of pump set is taken as 4 hours per day, the discharge required would be as below :

Pumping rate per hectare = 13.53 m3 /day/ha = 3.38 m3 /hr/ha = 0.94 LPs or say 1 LPs. As required discharge is only 13.53 m3 /day/ha, it can be pumped for one hour only from a well giving a discharge of 5-6 lps. This is also the normal well yield in the scheme area using a 3-5 HP pump set. For the estimated water requirement of 1 lps only, an arrangement to divert excess water to irrigate other crops would be provided, especially during Kharif and Rabi periods. Alternatively, a tank of 14 m3 capacity can be provided where necessary so that uninterrupted irrigation may continue even in areas where power shut down are frequent.

f. Emitters Depending upon the type of emitter and discharge required their number can be estimated. For a pressure head of 4m and discharge at 17.5 litre /hour the number of emitters required are :

No. of emitters/plant = Rate of Pumping/hour/plant /Avg. discharge of one emitter = 13.53/4 = 3.38 or say 4 emitters/ plant The plot is square and of 1 ha. As such the mainline would be 100 m long and laterals would also be 100 m in length. As plant spacing is 6m x 8m, a total of 13 laterals would be required. Each lateral would serve approximately 16 plants and there would be 4 emitters per plant. Thus, the total number of emitters per lateral would be 16x4 = 64 nos. As the total length of one lateral is 100m the emitters would be spaced at 1.5 m i.e. 100/64.

g. Main Line The main line is designed to carry the maximum discharge required for total number of plants in the farm plot. Maximum discharge required = No. of plants x peak discharge per plant = 208x 13.53 = 2814 lph =0.78 or say 1 LPs

h. Friction Head loss in Pipes (m) Total length = 100.0 Equivalent length of 13 straight connectors = 6.5 Equivalent length of tee, bends etc = 5.5. Total =112.0 m.

The value of coefficients has been taken from tables given below. It would be seen from table 1 that for a discharge of 1 LPs through a pipe of say 40 mm diameter, the friction loss would be 2 m per 100 length or 2.2 m for 112 m equivalent length. Friction Losses for Flow of Water (m/100m) in smooth Pipes(c=140)

i. Discharge| Bore diameter(mm)

(lps) 20 25 32 40 50 65 80 100 125 150

0.5 16.4 5.5 1.6 0.56 - - - - - -

1 - 10 6 2 0.68 - - - - -

1.5 - - 12.7 4.3 1.45 0.4 - - - -

2 - - 16 7.3 2.5 0.68 0.25 - - -

3 - - - 15.5 5.2 1.45 0.53 - - -

4 - - - 26.4 6.9 2.5 0.9 0.3 - -

5 - - - - 13.4 3.8 1.36 0.46 - -

6 - - - - 18.8 5.2 1.9 0.64 0.22 -

7 - - - - - 6.9 2.5 0.84 0.29 -

8 - - - - - 8.9 3.2 1.1 0.37 0.15

9 - - - - - 11.1 4 1.36 0.46 0.19

10 - - - - - 13.4 4.9 1.65 0.55 0.32

For other type of pipes (new) multiply foregoing figures by factor given below Friction head loss = 2.2 x 0.88 = 1.94 or say 2.0 Conversion factor = (0.88) As the proposed system uses multiple openings, the friction loss is taken as 1/3 of the total friction loss i.e. 2.0/3 i.e. 0.66 m. Thus, the loss in mains is within 1.0 m/100 m and a pipe of 40 mm diameter is ideal in the layout.

j. Laterals A lateral is so selected that the pressure difference from the proximate end to the last emitter do not exceed 10% of the normal operating head which in the present case is 4m. The maximum permissible variation in friction loss in the pipe is 4x10/100 = 0.4 m for a lateral of 100 m length. The land slope is 0.5 m/ 100m. Thus the total friction loss allowable is 0.4 + 0.5 = 0.9 m. In addition to 100 m length of laterals there is additional loss due to connectors. This is generally taken as 0.1 to 1m (on an average 0.5) of the equivalent length of an emitter. The equivalent length of 64 emitters would thus be 64x0.5 = 32 m. Thus, total equivalent length for calculation of friction loss in laterals would be 132 m (100+32). The total flow in laterals is 256 lph i.e. 4 x 4 x16. It may be seen from Table No 4 that for 200 LPs flow the friction loss in 13.9 m length would be 2.25 m. It is a general practice that friction losses are taken at 1/3 of the total equivalent length of pipes with multiple emitter/connections. Thus, the friction loss works out to 1/3 x 2.25 = 0.75 m which is within the maximum permissible limit of 0.9 m. Therefore, 14 mm (outer dia) lateral pipe of 100 m length is suggested in this scheme. The friction loss in micro tubes need not be considered as a minimum of 4m head is prescribed which includes friction loss. Friction Head Loss in M per 100 m. Pipe Length

Flow Inside diameter (mm)

9.2 11.7 12.7 13.9 15.8 18.0 19.0

(lph) Head loss in m per 100 m length of pipe

200 10.2 5.2 2.5 1.7 0.8 0.4 0.3

400 39.0 18.0 8.6 5.7 2.7 1.6 1.1

600 -- 39.0 18.0 13.0 5.9 3.2 2.5

800 -- -- 30.0 21.0 10.0 5.5 4.1

1,000 -- -- 45.0 30.0 16 8.3 6.2

1,200 -- -- -- 42.0 21.0 11.0 8.8

1,400 -- -- -- 56.0 28.0 16.0 11.0

1,600 -- -- -- -- 36.0 20.0 15.0

1,800 -- -- -- -- 45.0 25 19.0

2,000 -- -- -- -- 54.0 30.0 23.0

k. HP of Pump set The HP of pump set required is based upon design discharge and total operating head. The total head is the sum of total static head and friction losses in the system.

(i) Static Head.The total static head is the sum total of the following (m).

Depth to water (bgl) 16 m (assumed)

Draw down 3 m (assumed)

Height of Delivery pipe (agl) 1 m

Friction loss in pipes, bends, foot valves etc. 2.25m

Total 22.25 m

(ii) The friction loss in the drip unit as under (m)

Friction loss in main pipe 2.2 m

Friction loss in laterals 0.75 m

Minimum head required over emitters 4.0 m

Total 6.95 m

Total Head = Static Head + Friction head loss = 22.25 + 6.95 = 29.20 m or say 30 m The required HP of the pumpset has been calculated as per the following formula. Hp of pump set = Q x H/ 75 x e Where Q = discharge (lps) H = Head (m) e = Pumping efficiency (o.6)

HP = 1x30 /75x.6 = 0.66 or say 1 HP. Appendix - III

CHECK LIST MINOR IRRIGATION - DRIP IRRIGATION (To be completed by the Executive/Officer of the bank forwarding the scheme)

NOTE : Tick (/ ) across the line to signify that the relevant information has been furnished in the scheme.

GENERAL

Specifications of the scheme area

Nature and objective proposed development

Name(s) of the financing bank(s) / branch(s)

Approval of the schemes by the competent authority, including State Government in the case of SLDB. Coverage of the loans under the Guarantee Schemes of Deposit Insurance and Credit Guarantee Corporation

Status of beneficiaries (individuals/partnership firms/company/Corporation/Co-operative Society) and the coverage of borrowers in weaker sections like small (as per norms given by National Bank) or marginal farmers/SC/ST, etc.

Land-use pattern, source-wise irrigated area, present cropping pattern, yield and income per acre, land holding distribution, land tenure system etc. in scheme area

Capability/experience of the persons/institutions implementing the scheme

TECHNICAL ASPECTS

Command area map with levels

Type of soil

IMD Normal Annual Rainfall

IMD Monthly Evaporation

Proposed cropping pattern with plant spacing and number of plants per hectare for a modal farm

Peak water requirements per plant/day and per plant/season

Designed discharge and water availability in hours per day

Existing pumping equipment

i. Range of HP

ii. Whether electric/diesel

Water availability

i. Geology of the area

ii. Category of block

iii. Chemical quality of water

iv. Design of well (dia/Depth)

v. Well discharge

Design of Drip system for a model

i. Main line

ii. Sub main

iii. Laterals

iv. Emitters/Micro tubes

v. Lateral/Straight connectors

vi. Filters/screens

vii. Fertilizer unit

viii. Bends/end plugs, joints etc.

ix. Pressure gauge, water m

x. Water regulators

xi. Item-wise break-up of unit cost

xii. Comments on technical feasibility of the project

FINANCIAL ASPECTS

Lending terms : rate of interest, grace period, repayment period, down payment, nature of security, availability of Government guarantee for bank loan/refinance (if necessary), source and extent of availability of subsidy etc.

Year-wise physical and financial programme, bank loan and refinance requirement

Income "without project and "with project" with reference to the representative of the holdings in the scheme area and the estimate of incremental income

Comments on the financial viability of the project along with cash flow, BC Ration, net present worth, financial rate of return (IRR) etc.

Comments on the financial position of the borrowers/implementing agency. In the case of partnership firms/companies/Corporation or Society an analysis of their financial position, debt-equity ratio and profitability along with copies of audited financial statements for the last three years.

INFRA STRUCTURAL FACILITIES

Sources of availability of capital assets/drip irrigation system, the approximate distance and arrangements for their maintenance/servicing

Arrangements for availability of raw-material, improved seeds/fertilizers, pesticides, etc., for agriculture

Agencies providing crop loans/maintenance expenses to the beneficiaries and the adequacy of the arrangements.

Availability of technical staff for implementation of the scheme with the bank/implementing authority.

Details of technical guidance, government support/extension service available and whether budgetary provision has been made for the same.

Supervision and monitoring arrangements available with the financing institution.

Availability of power and diesel.

Signature and Designation of the Bank Officer

Minor Irrigation Dugwells CHAPTER 1 : REQUIREMENTS OF A MODEL SCHEME FOR FORMULATION BY BANKS 1.0. GENERAL This document gives broad guidelines for scheme formulation by banks for financing of dugwells in hard rock areas. The aspects that are necessary in scheme formulation are groundwater availability, well design, cost estimates, cropping pattern, pumpset selection and scheme economics. It is always desirable to formulate a scheme giving the resource availability, physical programme and financial aspects over a fixed time frame for completion of the project. Scheme formulation helps in the following ways.

1. Planned and sustainable development of groundwater resources. 2. Proper planning and fixing of targets on area specific basis under a given time frame.

3. Ensuring quality of lending, systematic development, assured income to the beneficiary, assured repayment and recycling of credit.

4. Quality control of minor irrigation works and equipments for efficient and economic use.

5. Systematic monitoring.

6. Periodical review about achievements and shorfall and taking timely remedial measures for successful implementation of the programme.

In view of the above NABARD recommends proper scheme formulation and its techno-economic appraisal by banks before extending any refinance facilities.

3.0. SCHEME REQUIREMENTS

Scheme formulation for construction of dugwells in hard rock areas against bank loans requires both technical and financial details. The important items that should be included in a scheme for dugwells are indicated below.

3.1. Introduction

This should briefly give the present status of agriculture, irrigation and need for increasing irrigation for improving the socio-economic conditions of the area, location of the scheme area,

its areal extent and topographical features. Infrastructure availability like power, roads, etc should be described here.

3.2. Selection of Area

Guidance of the state groundwater department should be taken to select the project area for minor irrigation development so that adequate groundwater potential is available for future development and that the area does not come under over-exploited or critical category. The area selected should be a compact block / taluka or a watershed with adequate groundwater potential, easy accessibility by road and adequate outlets for sale of agricultural produce. This information can be obtained from the state groundwater department and local district authorities. Brief details about the area selected and the project benefits should be given in the scheme.

3.3. Soils

The general nature of soils prevailing in the area should be indicated. These can be classified as sandy, loamy, clayey or black cotton, red soils etc. Soils have a bearing on irrigation scheduling and depth of irrigation required to meet the water requirement of crops. Type of soils also helps to select a suitable cropping pattern and the fertilizer doze.

3.4. Climate and Rainfall

Rainfall is the main source of recharge to groundwater and groundwater availability largely depends upon it. It also governs the supplementary irrigaion requirement of crops. The scheme should therefore, indicate the monsoon and non-monsoon rainfall as per data recorded by the India Meteorological Department (IMD). This should also give the minimum and maximum temperatures during different seasons.

3.5. Hydrogeology

The geological formations in the area, nature and types of aquifers and their water yielding capacity, average depth to pre-monsoon and post-monsoon water table and well design suitable for the area should be indicated. The aquifers in hard rock areas suitable for tapping groundwater are generally weathered zones, joints, fractures etc. Their availability in depth and areal extent from the point of view of groundwater development may be indicated in the scheme. This information is available with the district geologist of the state groundwater department.

3.6. Groundwater Availability

Before any programme of groundwater development is taken up, it is essential to ascertain whether adequate potential is available in the blocks covered under the scheme. The state groundwater department estimates groundwater resources on a blockwise, taluka wise or watershed wise basis and also keeps a record of the status of groundwater development at a given period of time. The categorisation of blocks as dark (critical and over-exploited) , grey (semi-critical) and white (safe) is made on the basis of stage of groundwater development expressed as

a ratio of draft to utilisable resources,as well as trend of groundwater table. For over-exploited areas it is greater than 100%, for dark(critical) areas it is greater than 90%, for grey (semi-critical) areas it is greater than 70% but less than 90%, and for white (safe) areas it is less than 70%. This information is available with the NABARD regional office and state groundwater department. Banks can obtain it from them.

Since long term behaviour of water table is a manifestation of the long duration availability of groundwater resources, it is necessary to ensure that there is no declining trend of water table in the area selected for the scheme. Information on pre-monsoon water table is also necessary to decide the depth of well and to ensure that the yield of well is not affected due to depletion of water table.

Keeping these in view and for sustainability of the structure and investment, new well schemes should not be formulated in dark (critical and over-exploited) areas.

3.7. Groundwater Quality

Groundwater quality in the scheme area as indicated by the state groundwater department should be given. Its suitability for irrigation may be indicated in terms of total dissolved solids, sodium adsorption ratio etc.

3.8. Physical Programme

This is desirable to assess the demand for new wells in the area before formulating the scheme either by interaction with the farmers or the state agencies like DRDA, SCSTDFC, ITDA or other organisations involved in groundwater development programme. This facilitates fixing the physical targets for wells and pumpsets. If the demand is more and targets assessed are large, the programme could be phased over 2 to 3 years instead of envisaging entire programme for one year. Such a phasing helps better monitoring and leaves scope for mid term correction wherever required.

Normally single design of well is uniformly followed in block suitable for the geological formation. However , if different designs of wells are considered necessary for differnt geological formations, physical programme should be given for each type of well design.

3.9. Well Design

An optimum well design suited to local hydrogeological conditions is important for success of any minor irrigation scheme. The well diameter should be based on hydraulic conductivity of the aquifer and the well depth or thickness of the saturated zone available during the peak demand. At least a 2m of water column in summer is desirable. Guidance from the state groundwater department should be taken for this. The recommended well diameter and depth should be indicated in the scheme. Unit Cost Committee constituted by regional office of NABARD also recommends average design of well in different formations. The same should be adopted.

3.10. Well Siting

Normally, the state ground water department provides the map or list of villages within the block or watershed which are ground water worthy. For actual siting of well, further assistance/advice could be sought from the local hydrogeologist of the SGD. However, Annexure I gives the broad guidelines for financing institutions to enable them to decide the suitability or otherwise of the site for new wells.

3.11. Spacing

In absence of any groundwater legislation, institutional agencies exercise technical discipline in the form of spacing between two ground water structures for proper and efficient development of groundwater resources. Spacing is determined by aquifer performance tests conducted by the state groundwater department. However, to avoid over-capitalisation, economic spacing should also be considered and higher of the two spacings adopted for financing of minor irrigation works under a scheme. Spacing between two ground water structures is recommended by the state groundwater department. Therefore any variation or changes in the spacing stipulated has to be authenticated by that department.

3.12. Unit Cost

Based on the average design of well in the scheme areas, unit cost of well should be estimated adopting district schedule of rates and the total financial outlay of the scheme should be worked out for the physical programme envisaged. However, actual cost of well may vary from location to location and loan should be sanctioned for actual cost of well. It is important to avoid under financing of well that may render the investment infructuous.

3.13. Pumpset

Proper selection of pumpset in conformity with BIS 10804-1994 is important to achieve maximum output at minimum capital and operation cost. The scheme should give the type of pumpset (diesel / electric), requirement of horse power of the pumpset, size of suction / delivery pipes for the required discharge and operating head as per average agronomical practices and hydrogeological conditions in the scheme area. If site conditions require construction of a pit or provision of a platform in the well steining for placement of the pumpset at different levels , these should also be given in the scheme and its cost provided for. (Please refer to NABARD publication on Selection and Financing of Agricultural Pumpsets).

3.14. Economics

The economics of investment should be given in detail to justify the loan. The scheme should also give details about subsidies, repayment schedule, rate of interest etc.

3.15. Check list

A checklist should always accompany the proposal. This would help to check at a glance whether or not the details or essential items of scheme formulations have been incorporated. A check list is given in Annexure - II.

CHAPTER II : MODEL FOR A SCHEME OF DUGWELLS IN HARD ROCK AREAS

1.0. INTRODUCTION

Formulation of a scheme is explained in the subsequent paragraphs taking the case of a model block.The scheme aims to provide financial assistance for construction of 150 dugwells with pumpsets to individual farmers for irrigation development through groundwater sources. These wells would mostly benefit small and marginal farmers in the area where at present irrigation facilities either by surface or groundwater sources are inadequate. Dugwells are the most suitable stuctures for the hydrogeological conditions obtaining in the area and would be constucted by local contractors using conventional methods. Infrastructural facilities like road, powerlines and extension services by the state government are available for successful implementation of the minor irrigation programme.

go to top2.0. SELECTION OF SCHEME AREA

The block in the district has been selected to formulate model scheme for minor irrigation development. The block has a geographical area of 17,500 ha of which 14,000 ha are cultivable. It is located 15 km from the district headquarter town. It has an undulating topography and the elevation ranges from 300 m to 400 m above mean sea level . A canal of 9 km length with wetted perimeter of 2.5 m flows for about 90 days during the non-monsoon period. An area of 9200 ha is presently irrigated from canal and 1157 existing irrigation wells.

3.0. SOILS

Soils in the scheme area are of black cotton type and suitable for growing jowar, wheat, vegetables and cash crops like sugarcane and groundnut.

4.0. CLIMATE AND RAINFALL

The scheme area in general has a sub-humid to tropical climate. The monsoon season extends from mid-June to September end. About 90% of the total annual rainfall of 750 mm occurs during this period only. The average temperature and humidity are 27o C and 65% respectively. The fair weather season extends from mid October to February during which a winter rainfall of about 60 mm is recorded. The temperature during the months of December and January comes down to about 18oC. The hot weather conditions last from March to mid June and are characterised by high evaporation with temperature going upto 36oC. The rainfall pattern varies from year to year and on an average there is a dry spell once in 5 years. As per IMD records, the normal annual rainfall in the area is 760 mm.

http://www.nabard.org/modelbankprojects/mi_dugwells.asp#top

5.0. HYDROGEOLOGY

The area comprises of basaltic rocks with an aggregate thickness of over 100 m. The individual basaltic lava flows vary in thickness from 10 to 15 m and are made up of alternating massive and vesicular units. The massive units are hard and compact but highly weathered upto a depth of 10 m and are jointed and fractured upto a depth of about 50 m. Vesicular units are generally soft and make upto 30% of the total thickness of individual lava flows. These individual flows are sometimes separated by beds of red clays. Groundwater in the scheme area occurs under water table conditions. The weathered and jointed zones in massive units and vesicular zones are the main water bearing formations. These aquifers are inter-connected forming a type of multi-layered system but show lateral and vertical variations due to heterogenity of aquifers which governs the well yield. Hydrogeologically, aquifers in the scheme area are good and are suitable for construction of dugwells. Their hydraulic conductivity as estimated by the state groundwater department varies from 8 to 12 m/day. Dugwells in the area vary in diameter from 4 to 6 m and in depth from 15 to 20 m. These wells give a discharge of 4 to 6 litres per second for a pumping period of 4 to 6 hours per day for a draw down of 2 to 3 meters. The well recoups by next day.

6.0. GROUNDWATER AVAILABILITY

6.1. Recharge

The state groundwater department (SGD) has estimated the available annual recharge by water table fluctuation and specific yield method. This includes recharge from monsoon rainfall and from supplementary sources like canals and tanks, re-cycled irrigation water, non-monsoon rainfall etc. The available recharge as estimated by SGD in the block is given below.

Total Annual Groundwater Recharge(ham)4200

Net annual groundwater availability (ham)3780.

After allowing for the existing and projected demand for drinking water and industrial use, the balance groundwater recharge available for irrigation is estimated at 3570 ham. 6.2. Draft Irrigation by electric and diesel operated pumpsets is the common method of groundwater extraction in the area. The average draft of a dugwell with pumpset is about 1.2 ham/year. Thus the total annual groundwater draft is about 1326 ham and is given in Table 1 below. Table 1. Draft from Existing Minor Irrigation Structures

Sr.

No.

MI Works Nos Unit Draft (ham)

Gross Yearly Draft (ham)

Monsoon Non-monso-on Yearly

1 Dugwell 114 0.65 22 52 74

2 Dugwell with pumpset

1,043 1.2 376 876 1,252

Total 398 928 1,326

6.3. Water Balance

Net annual Groundwater availability for future irrigation development use is 2244 ham.

6.4. Stage of Groundwater Development

The stage of groundwater development is defined by ratio of existing gross annual groundwater draft to net annual groundwater availability and expressed as percentage. From the groundwater estimates by the state groundwater department, the stage of groundwater development in the block is 41%. Further the long term behaviour of water levels in the observation wells as recorded by the state groundwater department, does not show any progressive decline during past 10 years. Accordingly, the block is categorised as white (safe) and new well programme in the block is feasible.

7.0. PHYSICAL PROGRAMME

A programme of 150 dugwells with pumpsets is proposed under the scheme. The unit gross draft of a dugwell is taken as 1.2 ham per year. The gross draft works out to be 180 ham, against a water balance of 2244 ham. Thus the proposed programme in the block is feasible. The stage of groundwater development after financing the proposed programme would be within 70% and the block would remain in the white (safe) category.

8.0. SPACING

The spacing between two dug wells as based on aquifer performance test conducted by the SGD works out to be 120 m. However, spacing on economic considerations has also been examined. A dugwell with pumpset can irrigate an area of about 2 ha and thus, on economic considerations, the spacing would be 150 m. Thus, spacing between two wells would be kept at 150 m.

9.0. GROUNDWATER QUALITY

As per report of the state groundwater department, groundwater in the block shows low values of total dissolved solids (TDS less than 700 ppm) with Sodium Adsorption Ratio (SAR) less than 10. The water is therefore, suitable for irrigation purposes.

10.0. WELL DESIGN

In the scheme area a saturated thickness of about 6 m is available in a well depth of 15 m. The water table aquifers in the weathered and jointed zones, vesicular units have good hydraulic conductivity and are capable of yielding about 5 to 6 lps. The state groundwater department has

recommended a well of 5m diameter and 15m depth in the scheme area and the same is adopted. Predictably, within this depth, atleast 2 m of water column would be available in the wells during summer season.

11.0. CROPPING PATTERN AND COMMAND AREA

The crops grown in the scheme area under irrigated conditions are jowar, wheat, vegetables, groundnut and sugarcane. The command area of a dugwell varies from 1.5 to 2 ha. The well discharge can meet the crop water requirement for such a farm model. The cropping pattern and water requirement for a 1.6 ha farm model are given below in Table 2. Table 2. Cropping Pattern and Water Requirement Command Area = 1.6 ha Working Period = 4 hrs/day

Season Crop Area (ha)

Number of Irrigations (nos)

Irrigation Interval (days)

Depth of Irrigation (cm)

Kharif

Vegetables 0.4 4 20 5

Groundnut 0.8 2 30 7.5

Sugarcane 0.4 4 15 7.5

1.6

Rabi

Jowar 0.8 4 30 7.5

Wheat 0.4 6 20 7.5

Sugarcane 0.4 12 12 8.75

1.6

Summer

Groundnut 0.4 10 12 7.5

Sugarcane 0.4 12 10 10

0.8

Cropping Intensity 200% Irrigation Intensity 250%

12.0. Discharge Required

The discharge required has been calculated from the following formula:

Q = ( 28 AxI ) / ( Rxt )

where, A = Crop area in ha

I = Depth of irrigation in cm

R = Rotation period in days

t = Working hours per day

Q = Required discharge in lps

The discharge required during the different crop seasons is calculated below:

KHARIF Q = 28 [ (0.4x5) / (20x4) + (0.8x7.5)/(30x4) + (0.4x7.5) / (15x4) ]

= 3.50 lps

RABI Q = 28 [(0.8x7.5)/(30x4) + (0.4x7.5)/(20x4) + (0.4x8.75)/(12x4)]

= 4.49 say 4.5 lps

SUMMER Q = 28 [( 0.4x7.5) / (12x4) + (0.4x10)/(10x4)]

= 4.55 lps

Considering water losses at 20% (irrigation efficiency at 80%) the required discharge would be:

Kharif = 4.4 lps

Rabi = 5.6 lps

Summer = 5.7 lps

The discharge required during the Rabi and Summer season is 5.6 lps and 5.7 lps respectively, say 6 lps. This can be met from the design of well proposed under the scheme. A discharge of 6 lps is therefore taken for selection of pumpset.

13.0. PUMPSET SELECTION

A centrifugal pumpset is suitable for installation on dugwells. This type of pumpset, both electric and diesel are also commonly used in the scheme area. The pumpset has been selected as per IS-10804-1994 keeping in view the discharge and the total pumping head and the pump/motor efficiencies as observed from the relevant tables and curves.

13.1. Discharge Required

The discharge required is 6 lps for a daily pumping period of 4 hrs.

13.2. Total Pumping Head

The total pumping head to meet peak demand (5.7 lps) in summer season is likely to be 15.4 m (apprx) with 65 mm dia GI pipe. This includes total static head, friction losses in pipes, allied fittings, foot valve and offset pipe as per norms on suction and delivery side. The required HP of the pumpset under these conditions works out to be 3.0. This includes 10% additional input to nominal pump input to take care of tolerance on pump efficiency and variation in duty. Accordingly, pumpsets of 3 HP are considered under the scheme.

13.3. Pumpset Specifications

The specifications of the electric pumpset selected for the scheme area are as below:

a) Centrifugal Pump

Total Head (H) = 16.3 m

Discharge(Q) = 6 lps

Efficiency (n) = 54%

b) Piping System

Suction/Delivery pipes = 65 mm

Foot valve = 65 mm

( K = 0.8 m)

Straight length = 17 m

of 65 mm GI pipe

Long radius bend (65 mm) = 2 Nos.

c) HP of pumpset (electric/diesel) = 3

The complete pumping system would be installed as per IS 10804 - (1994).

14.0. COST ESTIMATE

The cost estimate for the well with suggested design is made on the basis of prevalent schedule of rates. The unit cost works out to Rs.37000/-. The cost estimate of the dugwell in the scheme

area is given below in Table 3. Table 3. Cost Estimate of a Dugwell

(Indicative Only)go to top

Dia (m): 5 Steining (m) : 0.35

Depth (m): 15 Depth (m) : 4.5

Type : Brick Masonry

S.N.r

No

Item of Work Qty.

(m3)

Rate

(Rs/m3)

Amount

(Rs)

1 Excavation

a. Soil and Murum (0 to 2.5 m) 116.35 24 2,792.4

b. Hard Murum (2.5 to 4.5 m) 70.47 30 2,114.1

c. Soft Rock (4.5 to 6 m) 29.44 33 971.52

d. Soft Rock (6 to 7.5 m) 29.44 80 2,355.2

e. Soft Rock (7.5 to 9 m) 29.44 85 2,502.4

f. Weathered Jointed Rock

(9 to 10.5 m)

29.44 85 2,502.4

g. Hard Rock (10.5 to 12 m) 29.44 165 4,857.6

h. Hard Rock requiring blasting

(12 m to 15 m)

58.40 185 10804.0

28,899.62

2 Steining

a. Lining in Cement Mortar

(1:6) 0.35 m thick upto 4.5 m

26.46 201 5,318.76

b. Lining in Cement Mortar

(1:6) for parapet wall of 0.90 m

5.30 201 1065.30

3 Dewatering During Excavation LS 1,500

7,884.06

Total cost of well 36783.68 say Rs.37000/-

4 Pumphouse 7000


2.5 m x 2.5 m x 2.1 m

5 Pumpset

3 HP (electric/diesel) pumpset conforming to ISI standards including accessories, piping system,transportation and installation charges etc.

The above unit cost is as approved by NABARD regional office Unit Cost Committee.

15.0. TOTAL Financial Outlay

The unit cost of a dugwell with 3 HP pumpset is Rs.59000 (Rs.37000 + Rs. 7000 + Rs.15000). The financial outlay of the scheme for 150 dugwells with pumpsets is Rs.88.50 lakhs.

16.0. Economics

The scheme economics is given in Annexures III and IV. It is seen therefrom that the net incremental income is Rs.26,870 per year and the IRR works out to be 49%. Thus, the scheme is considered economically viable.

17.0. INFRASTRUCTURAL FACILITIES

Adequate extension services are available in the scheme area. The beneficiaries having irrigation facilities have adopted modern cultivation practices. A good net work of low tension/high tension power lines exist and energisation of pumpsets can be expected without any delay. A sugar factory is located in the nearby block and marketing of sugarcane produce will not be a problem. A market yard exists within 3 km for marketing the agricultural produce and there are good all weather roads for transport of agricultural produce.

18.0. Supervision and Technical Guidance

The technical officer of the sponsoring bank would look after the supervision and implementation of the proposal and also extend technical guidance wherever necessary.

19.0. Lending Norms

Majority of beneficiaries (70%) are in the small and marginal farmers category.

20.0. Repayment Period

For small and marginal farmers, the loan repayment period of a dugwell would be 11 years excluding a gestation/grace period of 23 months and for pumpset 9 years. The beneficiary may, if he so desires, repay the loan instalment with interest earlier than the stipulated period. For

other farmers, the loan repayment period would be 9 years.

21.0. Rate of Interest

The present (2003-04) refinance rate to the financing bank for minor irrigation investments is 5.50% for NE region including Sikkim, A&N Island, whereas for other regions, it is 5.50% and 6.25% respectively for loansizes upto Rs. 50.000/- and above Rs. 50,000/-. The minimum down payment would be 5%.

ANNEXURE- I

Guidelines for Selection of Well Sites

Broad guidelines for financing institutions to enable them to decide upon the suitability (or non-suitability) of the site for new wells are given below :

Guidelines for Location of Wells :

1. Areas included between two nalas near the confluence having a soil thickness of over 30 cm and weathered mantle of over 5 meters (A weathered mantle comprises of morum, loose sandy material, etc.)

2. Alluvial flats close to river or streams.

3. Depressions in landscape having more than 30 cm of soil cover and 5 meters depth of weathered mantle.

4. On the banks of nalas towards the high ground provided the banks are not clayey.

5. Zone of luxuriant, vegetation with leafy plants.

6. Old courses of rivers and streams which are represented by presence of sands and gravels.

7. Near the sharp bends of the streams or rivers.

8. Damp or moist areas.

Wells should not be located in :

1. Areas where hard rocks are exposed.

2. Areas adjoining ridges and spurs and within about 50 meters of them.

3. Areas with a soil cover less than 30 cm.

4. Areas with a weathered mantle less than 5 meters in depth.

The thinkness of the weathered mantle can be roughly determined by looking at existing wells in the nearby area. If no wells exist, the exposures in nalla beds will give an indication of the depth of weathering.

The above guidelines, if rigidly followed, would minimise the chances of failure of wells and ensure location of wells in the groundwater worthy areas. ANNEXURE-II

CHECK LIST

Minor Irrigation

Groundwater Development Schemesgo to top

(To be completed by Bank Officer forwarding the Scheme) Tick in boxes to signify that the relevant information has been furnished in the scheme.

1. Name of scheme :

2. Scheme location :

3. Area - geographical area, cultivated area and area irrigated by different sources :

4. IMD normal rainfall :

5. Geological formations

6. Present level of groundwater development giving number of wells, filter points, tubewells, and other structures with unit draft/year for each :

7. Length of canal and distributories with wetted perimeter and number of days of running in the scheme area :

8. Soil conditions, cropping pattern and crop water requirement :

9. Stage of groundwater development and category of block as indicated by NABARD :

10. Chemical Quality of groundwater :

11. Spacing between different types of minor irrigation works :

12. Groundwater draft per well and total groundwater draft under the proposed scheme :


13. Design of minor irrigation works :

14. Specifications for pumping machinery, diameter of suction and delivery pipes, discharge, total head and HP of pumpset :

15. Cost estimates of minor irrigation works :

16. Area map :

17. Yearwise physical programme and financial outlay :

18. Availability and arrangement for procurement and distribution of material :

19. Financial returns on investments with reference to representative size of holdings in different agro-climatic zones in the scheme area :

20. Lending terms i.e. interest rate, down payment, repayment period, extent of subsidy, etc. :

21. Agency providing crop loan and its adequacy :

22. Supervision and monitoring arrangements :

23. Technical guidance for location of wells, specifications and design, selection of pumpsets, etc. :

24. Availability of extension services :

25. Availability of power /diesel supply :

26. Availability of seeds/fertilizers, pesticides and their distribution :

Annexure III

PRE-DEVELOPMENT AND POST DEVELOPMENT INCOME FOR A FARM MODEL OF 4 ACRES (1.6 HA) Techno-Economic Parameters

Acres Hectare

Culturable Command Area 4 1.6

Irrigable Command Area 4 1.6

Cost (Rs.)

Civil : a) dugwell 37000

b) pump house 7000

Mechanical : complete pumping system 15000

Total Cost (Rs.) 59000

Margin money @ 5% 2950

Bank Loan 56050

Interest on bank loan 0.15

Grace period (years) 1

Annual equated instalments (years) 12

Capital recovery factor for 12 years 0.184481

Diesel charges (Rs. for 783 hrs.) 14851

Horse Power 3

Cost per acre (Rs) 14750

Cost per hectare (Rs) 36875

Land revenue (Rs./ acre) pre-dev 2

Cost of cultivation from borrowed funds 0.6

Interest on borrowed funds 0.12

Land revenue (Rs./ acre) post-dev 8

Repairs & Maintenance

% of civil works 0.025

% of mechanical works 0.03

Annexure IV

Pre and Post-Development Income

Crop AreaYield/Acre

Total yield

Unit Sale

Total Sale

Cost of cultivation/Acre

Total Cost of cultivation

Net income

(Acres) (Q) (Q)Price Rs.

Price ( Rs.)

(Rs.) (Rs.) (Rs.)

(3x4) (5x6) (3x8)

2 3 4 5 6 7 8 9 10

PRE DEVELOPMENT

KHARIF

Maize 2.5 2.5 6.3 550 3438 840 2100 1338

Jowar 1.5 2.5 3.8 800 3000 1260 1890 1110

RABI

Gram 1 1.5 1.5 950 1425 885 885 540

Wheat 1 1.5 1.5 800 1200 790 790 410

Total 6 9063 5665 3398

Land revenue (Rs.2/acre)

8 Net income (Rs.)

2737

Interest on borrowed funds (Rs.)

653

Netincome/acre(Rs.)

684

POST DEVELOPMENT

KHARIF

Vegetables 1 75 75 400 30000 15735 15735 14265

Groundnut 2 8 16 1450 23200 5430 10860 12340

RABI

Wheat 1 12 12 800 9600 4725 4725 4875

Hybrid Jowar 2 8 16 525 8400 2195 4390 4010

Summer

Groundnut 1 9.5 9.5 1450 13775 6750 6750 7025

Perennial

Sugarcane 1 350 350 72.5 25375 14080 14080 11295

110350 56540 53810

Net income (Rs) 53810

Land Revenue (Rs)

32

ST interest (Rs) 7945

Diesel charges 14851

Repairs & Maintenance

2.5% of civil works

925

3% of Mech. works

450

Net Surplus 29607

Pre-Development net income

2737

Net Incremental income

26870

Net Incremental income/acre

6717

Interest on Bank loan

10340

Avg. repayment of loan & interest

per acre 2585

Avg. net income per acre

4132

Pumpsets

Field studies by NABARD and other agencies like Indian Pump Manufacturers' Association, Indian Diesel Engine Manufacturers' Association, Petroleum Conservation and Research Association, Rural Electrification Corporation, Institute of Co-operative Management, have revealed that most of the agricultural pumpsets selected and installed operate at much lower efficiency than desired. This is because of improper selection and installation of pumpsets by farmers who are often guided by the dealers and village mechanics. The financing institutions and other agencies who advance loans for pumpsets are expected to help farmers in proper selection and installation.

Improper selection of pump, prime mover and accessories results in wastage of energy and fuel causing financial burden to farmers and the nation. The Bureau of Indian Standards (BIS) has already brought out a standard IS-10804 (1994) for selection of efficient pumpsets. NABARD has conducted workshops to educate bank officials and farmers in proper selection and installation of agricultural pumpsets. This document on "Selection and Financing of Agricultural Pumpsets" is an endeavour to help bank officers, farmers and other agencies in selecting an energy efficient pumping system and would serve as a ready reckoner. The criteria for selection mentioned in the document are for guidance only. This document is also available on www.nabard.org. Any suggestion for further improvement is welcome.

CONTENTS FIELD STAFF GUIDE Introduction Minor Irrigation Units

Existing Well Practices

Suggested Well Dimensions

Agricultural Pumpsets

Selection of Centrifugal Pump

Selection of Electric Motor

Selection of Diesel Engine

Selection of Suction and Delivery Pipes

Selection of Foot Valve

Farmers' Guide for Selection of Agricultural Pumpsets

FINANCING OF AGRICULTURAL PUMPSETS Cost of Pumping System Loan for Pumping System

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Repayment Period

Economics

Subsidy

Rate of Interest

Maintenance And Repairs of Centrifugal Pumpsets

Further Guidance

ANNEXURES Matrix for Selection of Agricultural Pumpsets - with RPVC Pipes Matrix for Selection of Agricultural Pumpsets - with G.I. Pipes

National Bank Circular on Quality Control of Agricultural Pumpsets

Average Unit Cost of Complete Pumping System

National Bank Circular on Unit Cost under Schematic Lending

Economic Analysis of Financing of Agricultural Pumpset

Introduction

The necessity of having simple field oriented guidelines for selection of proper agricultural pumpset and its accessories arises out of the fact that studies so far conducted by various agencies in the country indicate that even at present majority of pumpsets are improperly selected, incorrectly installed and have deficiencies in selection of not only the major components of a pumpset namely, pump and motor but also in selecting proper size of suction and delivery pipes and foot valve. Studies have indicated that a farmer can save over his present expenses for pumpset operation if his pumping system is properly selected compared to an improper selection and installation. Such correct selection would not only salvage the farmer from his avoidable yearly financial loss but would also save the nation power by way of savings in diesel oil consumption and electric power input to the large number of pumpsets used in agricultural operations.

Minor Irrigation Units

A farmer generally draws water either from a dugwell or a shallow tubewell fitted with a pumpset. In both cases a horizontal centrifugal pumpset is mostly used. In all future references in this document such a unit would be called as 'well and a pumpset'.

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When a farmer decides to construct a well his first worry is to make an estimate about the volume of water he can expect from the well. The most convenient way to have an idea about this is to go to a nearby similar working well and find out the discharge that is being obtained from it. This type of field survey would also give an idea about the depth to water below ground level from where it has to be lifted. In an unexplored area where no ground water pumpage structures exist, the expected yield from well requires certain hydrogeological estimates for which guidance from the State Ground Water Department could be taken.

Criteria recommended in this document are in conformity with IS-10804 (1994) for selection of a complete pumping system (Fig.1) by Bureau of Indian Standards. This not only gives norms for estimation of head and discharge on a farmer's well but also indicates the steps that are required for proper selection of a pumpset and its accessories in accordance with the head and discharge conditions at a well.


1. Monobloc pumpset should be preferred over coupled pumpsets.

2. The BHP of the pump should match power output of the prime mover. However, for practical considerations the BHP of the prime mover is always kept about 10 percent more than what is theoretically required for the pump.

3. The efficiency of the motor as declared by the manufacturer should be considered. IS-10804 (1994) has provided the range of the following minimum efficiency ratings (Table V).

TABLE I

Range of yield and Size of Existing Dugwells in India

Sr. No.

Well Size Saturated thickness

of

formation

(m)

Discharge

(liters /sec)

States where encountered

Diameter

(m)

Depth

(m)

I. HARD ROCK AREAS

1 3 to 4 20 to 25 6 to 8 4 to 6 Rajasthan, Gujarat

2 4 to 6 10 to 15 4 to 5 4 to 6 UP, MP, Orissa, Bihar, Kerala

3 5 to 7 10 to 20 4 to 5 4 to 6 MP, AP, Tamil Nadu, Karnataka, Maharashtra

II. ALLUVIAL AREAS

4 2 to 3 20 to 50 6 to 8 5 to 6 Rajasthan, Gujarat

5 2 to 3 15 to 30 4 to 5 6 to 10 UP, Bihar, Orissa

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TABLE II

Range of yield and Size of Existing Shallow

Tubewells in Alluvial Formations in India

Sr. No.

Well Size Saturated thickness of

aquifer tapped

(m)

Discharge

(liters/sec)

States where encountered

Diameter

(m)

Depth

(m)

1 80 to 100 30 to 45 10 to 15 8 to 12 Punjab, Haryana, Western UP

2 80 to 100 30 to 45 10 to 15 8 to 10 Eastern UP, Orissa, Bihar, Assam

3 80 to 100 30 to 50 10 to 15 8 to 10 West Bengal

Suggested Well Dimensions

Along with the existing type of irrigation wells, it would be desirable to indicate the well dimensions that would be appropriate for a given set of conditions existing in an area. For this purpose the most important consideration is the type of water yielding strata encountered in a well. This is also called an aquifer. For design purpose these water yielding strata have been grouped here into three categories as below.

1. Excellent

2. Very Good

3. Good

The recommended design of irrigation wells for the above three categories of aquifers are given in Tables III and IV both for Dugwells and Shallow Tubewells/Borewells.

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TABLE III

Expected Yield and Size of Dugwells in

Hard Rock and Alluvial Areas

Sr. No.

Type of Aquifer

HydraulicConducti-vity

(m/day)

Well size Thickness of Aquifer required

(m)

Average Discharge

(liters /sec)

Diameter

(m)

Depth

(m)

I. HARD ROCK AREAS

Excellent 20 3 10 to 15 5 5

15 4 12 to 15 5 5

Very Good 12 5 10 to 15 5 5

10 6 15 to 18 5 5

Good 8 6 12 to 20 5 4

II. ALLUVIAL AREAS

Excellent 40 2.5 10 to 15 4 8

Very Good 30 2.5 to 3 10 to 15 4 7

Good 20 3.5 to 5 15 to 20 4 6

TABLE IV

Expected Yield and Size of Shallow Tubewells/Borewells

in Alluvial and Hard Rock Areas

Sr. No.

Type of Aquifer Hydraulic Condu-

ctivity

(m/day)

Size of Well Thickness of Aquifer required

(m)

Average Discharge

(liters /sec)

Diameter

(mm)

Depth

(m)

I. ALLUVIAL AREAS

Excellent 40 80 to 100 30 10 8 to 12

Very Good 30 80 to 100 40 12 8 to 10

Good 20 80 to 100 50 12 8 to 10

II. HARD ROCK AREAS

Excellent 20 80 to 100 45 10 to 15 6

Very Good 12 100 to 150 45 20 to 25 5

Good 8 100 to 150 50 20 to 25 4

Agricultural Pumpsets

A complete pumping system for lifting water for irrigation comprises of the following main components.

1. Centrifugal Pump (coupled or monobloc)

2. Prime Mover - Electric Motor or Spark Ignition Diesel Engine

3. Piping System - Suction and Delivery pipes

4. Foot Valve, Reflux Valve

5. Pipe Fittings (Bends and other Fittings)

All the above components constitute a pumping system. Each of the above components has to be properly selected to match the field requirement. If any component is wrongly selected, it makes the system inefficient. Thus, an efficient pumping system aims at maximum output at minimum capital and operating cost. Proper selection of an agricultural pumpset requires estimation of discharge and head over which water is to be lifted. The discharge required depends on peak irrigation requirement of crops grown in the command area of the well. Hydrogeological conditions should be such that this discharge is available from the well. The total head comprises of maximum depth to water in the well, depression in the water level during pumping and friction losses in the piping system and allied fittings, valves, etc.

Having estimated the maximum discharge and head over which water is to be lifted, a right pumping system should be selected so that it works efficiently with minimum operating cost.

Guidelines given below would be helpful in selecting a centrifugal pumpset for agricultural purposes. Centrifugal pumpsets normally operate at 440 volts 3 phase power supply and at an RPM of about 1500. These guidelines are meant for guidance of technical staff in the banks and other extension workers for selecting a proper pumping system for a farmer.

Selection of Centrifugal Pump

The following are the main guidelines for selection of Centrifugal Pumps.

1. The Brake Horse Power (BHP) required for a pump can be calculated from the following formula :

BHP = ( Q x H ) / ( 75 x e )

Where Q = Discharge in liters per second

H = Total Head in meters (including friction losses)

e = Efficiency of the pump, as percentage

For belt drive pumps the BHP may be increased by about 10 percent.

2. The pump should be selected so as to have a maximum efficiency at the operating head likely to be obtained during peak demand period. For example, if the duty condition of the system is for a discharge of about 8 litres/sec at a total head of approximately 11.4 m then the centrifugal pump for which the characteristic curves have been given in Fig. 2 will be ideally suited as the same will have efficiency nearly at optimum level at the operating conditions. If, however, the duty condition of the system demands a discharge of about 12 litres/sec at a total head of about 11 m, this particular pump will not be suitable for the purpose as the pump will not give the requisite discharge at that head and also its efficiency will be much lower than optimum. In that case another suitable pump will have to be selected which will operate at optimum or near optimum efficiency at the required duty condition of total head and discharge.

3. For the site conditions of head and discharge the centrifugal pump should have the minimum efficiency of 43 percent as per the efficiency curves provided by Bureau of Indian Standards (BIS) under IS-10804 (1994).

4. On practical considerations the vertical distance between the deepest water level at which the pump would be required to operate and centre line of the pump should not be more than 5 metres.

5. The pump should have BIS certification conforming to IS - 6595 or IS - 9079 or IS-11501.

6. The pump which has a maximum efficiency for the head and discharge required at site should be selected from a range of BIS marked pumps available in market. This criteria should over-ride cost considerations.

7. Only those pumps for which genuine spare parts are readily available should be preferred.

8. Only those pumps for which after sales service is easily and effectively available should be preferred.

9. The pumps which have reputation of giving efficient and trouble free service should be preferred.


1. Monobloc pumpset should be preferred over coupled pumpsets.

2. The BHP of the pump should match power output of the prime mover. However, for practical considerations the BHP of the prime mover is always kept about 10 percent more than what is theoretically required for the pump.

3. The efficiency of the motor as declared by the manufacturer should be considered. IS-10804 (1994) has provided the range of the following minimum efficiency ratings (Table V).

TABLE - V

Minimum Efficiency in percentage of Electric Motors for Centrifugal Pumpsets

Motor

Rating

Horizontal Centrifugal Pumps

Speed ( 1200 to 2000 RPM ) Speed (2001 to 3600 RPM )

(kw) Single Phase Three Phase Single Phase Three Phase

0.37 56 - 54 -

0.75 66 - 63 -

1.1 70 76 68 73

1.5 72 77 70 74

2.2 - 77.5 - 75

3.7 - 80 - 79

5.5 - 82 - 80

7.5 - 83 - 81

9.3 - 85 - 81.5

11 - 85.5 - 82

15 - 86 - 83

4. The motor should have BIS certification conforming to IS - 7538.

5. The motor which has a maximum efficiency for a given BHP should be selected from a range of BIS marked motors. This criteria should over-ride cost considerations.

6. Motors for which genuine spare parts are easily available should be preferred.

7. Motors for which after sales service is easily available should be preferred.

8. Motors which have a reputation for giving efficient and trouble free service should be preferred.

9. An electric motor should always be provided with a starter and a capacitor matching the motor. In general, for motors upto 3 HP a 1 KVAR capacitor should be used and for motors between 3 to 5 HP a 2 KVAR rating capacitor should be used.

Selection of Diesel Engine

Where electric power is not available and a diesel engine is required to be used to run an agricultural pumpset, following guidelines should be used in selecting a diesel engine.

1. BHP of the diesel engine should be 10 percent more than the required BHP of the pump. 2. Specific Fuel Consumption (SFC) of the selected diesel engine should be as low as

possible and it should not exceed 188 gms/bhp/hour (252 gms/kwh) for diesel engines in RPM range 1000 to 2000 and 210.5 gms/bhp/hour (282 gms/kwh) for diesel engines in RPM above 2000. The SFC is specified in terms of the diesel oil consumed in grams per BHP for one hour operation of engine.

3. The diesel engine should have BIS certification conforming to IS-11170 or IS-7347.

4. The lubricating oil consumption of diesel engine should be about 1 percent by volume of diesel oil consumed. Engines having low lubricating oil consumption should be preferred.

5. Engines for which spare parts are easily available should be preferred.

6. Engines for which after sales service is easily available should be preferred.

7. Engines which have a reputation of giving efficient and trouble free service should be preferred.

Selection of Suction and Delivery Pipes

Suction and delivery pipes for centrifugal pumpsets are generally of either GI or RPVC. HDPE pipes conforming to IS-4984 can also be used for suction and delivery pipes but are not normally preferred by farmers.

1. The size of the suction and delivery pipes should be such that the friction head loss does not exceed 10 percent of the equivalent length of piping system upto the delivery point.

2. The size of pipes on the suction and delivery side should be equal.

3. The pipes should be BIS marked conforming to IS-1239 (for GI pipes) and IS-4985 or IS- 12231 (for RPVC pipes).

4. Although the size of the suction and delivery pipes should be estimated from BIS Tables for each individual case, the following table gives general guidelines for selection of G.I. and RPVC pipes as per BIS standard. If the delivery offset distance is more than 3 m, then larger pipe size may be used to reduce friction losses.

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TABLE VI

Size of Suction and Delivery Pipes for Centrifugal Pumpsets

Discharge

(lps)

Pipe Size (mm)

(Both Suction and Delivery Pipes)

Medium Grade GI Pipe (C = 140) RPVC Pipe (C = 150)

Nominal Pipe Size Inside Dia Nominal Pipe Size

Inside Dia

2 40 41.85 40 36.8

4 50 52.95 63 58.1

6 65 68.65 63 58.1

8 65 68.65 75 69.3

10 80 80.65 75 69.3

12 80 80.65 90 83.2

14 80 80.65 90 83.2

16 100 105.05 90 83.2

18 100 105.05 110 102

20 100 105.05 110 102

22 100 105.05 110 102

24 100 105.05 110 102

26 100 105.05 110 102

28 100 105.05 110 102

GI = Galvanised Iron RPVC = Rigid Poly-Vinyl Chloride C = Coefficient of friction.


Generally pipes are selected as per normal pipe size as given in the table.

Selection of Foot Valve

1. The size of the foot valve shall be equal to the size of the suction pipe.

2. Only BIS marked foot valves should be selected conforming to IS -10805.

3. The open area of the foot valve for entry of water should be about 2.5 times the cross sectional area of the suction pipe to which it is attached

Farmers' Guide for Selection of Agricultural Pumpset

Detailed method of pumpset selection necessarily requires a certain minimum expertise both with respect to hydrogeology of the area and other hydraulic aspects for selection of pump, motor and accessories. It has generally been observed that even the minimum technical guidance required for selecting a proper pumpset and its accessories is at present not available to farmers. Therefore, to assist the farmers and field staff a Matrix for selection of pumpset is given in Annexure I and II which would serve as a ready reckoner. This matrix gives the diameter of suction and delivery pipes and the BHP of motor under various conditions of total head and discharge. The total head includes the static suction and delivery head, friction loss in pipes and other accessories and variation in head due to lowered water level during the operation of the pump. Besides, in the matrix the nominal pump input has been increased by 10 percent to take care of tolerance on pump efficiency and variation in duty conditions. Further, minimum motor efficiency has also been considered in accordance with the motor ratings. Parameters given in the matrix may not have general applicability under all conditions but these would be useful in selecting proper size of pumpset and its accessories. The size of pipes and BHP of electric motor or diesel engine should be selected so as to be nearest to those indicated in the matrix depending upon their market availability.

FINANCING OF AGRICULTURAL PUMPSET AS PER IS-10804 (1994)

Financing of agricultural pumpsets involves, interalia, proper selection of different components of pumpset like electric motor or diesel engine, pump, foot valve, suction and delivery pipe, bends and joints etc. To ensure that each of these components is of good quality and efficient, BIS has brought out a Complete Pumping System Standard for selection of agricultural pumpset and is covered under IS-10804 (1994) which gives selection standards for each component.

The dealer or supplier of the pumpset is expected to guide and assist farmer in proper selection and installation of pumpset depending on season wise water levels and discharge from the well, cropping pattern and area under different crops and method of irrigation. It is always advantageous to select a Monobloc Pumpset than a Coupled one. National Bank's circular in regard to adherence of BIS-10804 by banks while financing for pumpset is given in Annexure III.

Cost of Pumping System

Cost of pumping system is decided by the type of pumpset i.e., electric motor or diesel engine, Horse Power of pumpset, diameter and length of suction and delivery pipes and other accessories. Centrifugal pumpset of 3-7.5 HP are adequate for normal irrigation conditions. To help farmers to receive the pumping system at site and to utilise the services of the dealers, supplier or the village mechanic for proper selection of the pumpset on the well, cost of transport and installation could also be included in the total cost of the pumping system for the purpose of bank loan.

Cost of pumping system varies with make and brand name. The farmer is free to select any BIS marked pumpset as per IS-10804 (1994) out of the various brands and makes available in the market. Cost of pumping system also changes with time and has to be reviewed from time to time as is being done by the Regional Unit Cost Committee of NABARD.

Average cost of centrifugal pumpsets for agricultural use in the state shall be adopted for formulation of the scheme. Notwithstanding these average costs financing banks are expected to finance the actual cost of the pumpset. National Bank has issued necessary circular to banks in this regard (Annexure-IV).

Loan for Pumping System

Depending upon the Horse Power, type and make of pumpset, type of suction and delivery pipes selected by the farmer, the cost of pumping system as quoted by the supplier is considered by the Bank. The loan for purchase of pumping system is decided after allowing for farmer's own contribution or margin money. NABARD has advised financing banks to consider actual cost of the pumpset selected by the farmer after allowing margin money and that the loan amount need not be restricted to average unit cost of pumpset for the District or the State. This would avoid under financing as well as borrowing by farmer from other sources if the bank loan is inadequate.

Repayment Period

Serviceable life of pumpset without much wear and tear and without much drop in efficiency is usually considered as 9 years. Therefore, the loan repayment period is considered at 9 years. Since immediate benefits start soon after installation and installation does not take longer time, no grace period is considered for loan repayment. It is presumed that the loan for electric pumpset is sanctioned by the bank after ensuring that electric power supply is readily available so that the pumpset financed by the bank would be immediately energized and commissioned.

Economics

Economics of financing of pumping system are worked out based on average command area, cropping pattern and average cost of pumping system. This is given in Annexure V. These are only indicative and for guidance. The economics have to be worked out in individual cases.

Financial analysis shows that availment of pumpset loan for agricultural purpose is a viable proposal.

Subsidy

As applicable from time to time.

Rate of Interest

As applicable from time to time.

Maintenance And Repairs of Centrifugal Pumpsets

Breakdown of pumping system during irrigation specially at critical crop growth stage results in great loss to farmer. To avoid such a breakdown, it is necessary to attend to regular upkeep and maintenance of the pumping system. Following are some of the important points that should be observed for smooth operation of the equipment :-

1. Pump and motor/diesel engine should be in perfect alignment to avoid extra load on bearings that damages impeller and couplings.

2. Suction and delivery pipes should be self supporting. Adding weight to pipes damages casing of the pump.

3. Gland packing should be periodically replaced. Do not tighten the gland packing more than necessary.

4. Check oil levels. Do not run the electric motor when the voltage is below 370 volts and electric supply is receivable from a single or two phases for three phase motor.

Despite regular maintenance, the pumpset might develop some trouble. Common troubles encountered and their probable causes and remedies are given in Table VII :-

TABLE VII

Common Troubles in Operation of Centrifugal Pumpsets,

Its Causes and Remedies

Trouble Causes Remedies

1 2 3

Difficulty in starting the diesel engine pumpset

Faulty fuel injection nozzle.

Air in fuel pipe

Check fuel injection nozzle

On operating the plunger it should give a peculiar squeaking noise

Engine starts but fires intermittently or stops

Faulty fuel supply

Fuel filter choked

Tighten fuel connection

Replace the parts

Overheating of diesel engine

Overloading of engine

Lubricating oil faulty

Avoid overloading

Check oil level

Motor starts jerking when starter is switched on

Broken circuit in starter

Alignment of motor is not proper

Belt is not properly joined

Damaged bearings

Repair circuit in the starter

Replace foundation bolts properly

Rejoin belt properly

Change bearings

Motor gets heated Low voltage

Starter winding may be wrongly connected

Motor bearings improperly lubricated or damaged

Stop motor and wait till proper voltage is restored

Change connection

Change bearings and lubricate them

Knocking or strapping noise

Ball bearings may be contaminated

Worn out bearings

Clean bearings and put fresh grease

Replace bearings

Engine consumes more oil

Worn out cylinder and piston rings

Check and replace wornout rings

Exhaust smoke is dark/ blue

Engine operating at high speed

Mobil oil leaks in combustion chamber

Control speed with governor

Control flow of mobil oil

Further Guidance

The Regional Office of NABARD in the State could be contacted for any further advice and guidance for formulation of schemes for financing of agricultural pumpset etc.

Annexure - I

MATRIX FOR SELECTION OF AGRICULTURAL PUMPING SYSTEM

CONFORMING TO IS-10804 (1994)

(with RPVC pipes)

Notes :

1. For computing HP, total head is considered as sum of total static head, friction losses in pipes, fittings, foot valve and discharge velocity head. While computing friction losses an additional pipe length of 10 m is considered over and above the pipe length equivalent to static head to take into account submergence of suction pipe (1 m), offset pipe length of suction and delivery side (5 m) and 2 bends (4m equivalent pipe length).

2. Class 3 RPVC pipes considered with C = 150.

3. For offset pipe line (more than 5 m) and additonal fittings in the system, frictional losses are to be added over and above total head.

4. Matrix restricted for head & discharge for which minimum pump efficiency values are available (Speed 1200-2000 RPM).

Notes :

1. For computing HP, total head is considered as sum of total static head, friction losses in pipes, foot valve and discharge velocity head. While computing fricitonal losses an additional pipe length of 10 m is considered over and above pipe length equivalent to static head to take into account submergence of suction pipe (1 m), offset pipe length of suction and delivery side (5 m) and 2 bends (4 m equivalent pipe length).

2. New medium series galvanised MS pipes are considered with C = 140.

3. For offset pipe line (more than 5 m) and additional fittings in the system, frictional lossess are to be added over and above the total head.

4. Matrix restricted for head and discharge for which minimum pump efficiency values are available (Speed 1200-2000 RPM).

Annexure III

NATIONAL BANK FOR AGRICULTURE AND RURAL DEVELOPMENT

Shiv Sagar Estate, 1st floor, Sterling Centre Dr.A.B.Road, Worli, Mumbai - 400 018.

Ref.No.:NB.ICD/513/PPS.113/1997-98

12 November 1997

The Chairman/Managing Director

All Scheduled Commercial Banks

All Regional Rural Banks

All State Co-operative Banks

All State Co-operative Agriculture

and Rural Development Banks

Dear Sir,

Automatic refinance Facility for activities under Farm Sector

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- Quality Control of Agricultural Pumpsets

Please refer to our letter No.NB/ICD/2566/PPS. 113/94-95 dated 09 March 1995 advising introduction of Automatic Refinance Facility (ARF) for traditional activities under Farm Sector. The ARF was introduced primarily to simplify the procedure for drawal of refinance but the banks have to observe all the basic norms of project lending while financing investments under ARF (FS) and ensure that durable and quality assets are acquired by the ultimate borrowers. It is observed that after introduction of ARF(FS), the banks have not been submitting along with drawal application, certificate to NABARD to the effect that the irrigation pumpsets financed by them under MI conform to IS-10804 specifications.

2. As you are aware, a large number of power/diesel/kerosene pumpsets are being used for irrigation purpose. It is necessary to encourage use of pumping mechanism to bring new areas under irrigation but there is an imperative need to conserve energy through quality control and efficient use of the pumping systems. To achieve this, the farmers have to be encouraged to use only BIS marked pumpsets and other components of quality pumping systems and to maintain the pumps at optimum efficiency level. The banks may, therefore, finance only BIS marked pumping systems.

3. We shall be glad if you please advise all your branches including controlling offices to ensure financing of BIS marked pumpsets and furnish a certificate with each drawal application claiming refinance from NABARD against loans disbursed for irrigation pumpsets, the format of which is given in Annexure.

Please acknowledge receipt.

Yours faithfully


( N. Raghavan )

Format - I

Format of certificate to be furnished by the dealer

of the pumping equipments to the financing bank

Name and address : M/s.

of the dealer

To

____________________ Bank

Dear Sir

We hereby certify that we have on ______ (date) installed a Complete Pumping System conforming to IS-10804 (1994) at the well of Shri/Smt. _________________________________ ___________________________ (Name and address of the borrower). The pumping system installed by us conforms to BIS standard IS-10804 (1994) except in regard to foot-valve.

Yours faithfully

( Signature of the dealer)

Format - II

Format of certificate to be furnished by

the financing banks to the National Bank

while submitting drawal applications

To

The Managing Director

National Bank for Agriculture

and Rural Development

Dear Sir

We hereby certify that the pumpsets covered under this drawal application have been installed in accordance with IS-10804 (1994) prescribed by the Bureau of Indian Standards for a Complete Pumping System.

Yours faithfully

(Signature of the Officer )Name and Designation

Annexure IV

NATIONAL BANK FOR AGRICULTURE AND RURAL DEVELOPMENT

Shiv Sagar Estate, 1st floor

Sterling Centre, Dr.A.B.Road

Worli, Mumbai - 400 018.

Ref.No.:NB.ICD/1354/PPS.8/1999-2000

31 December 1999

The Chairman/Managing Director

All Participating Banks

(CBs/RRBs/SCARDBs/SCBs)

Dear Sir

Schematic Lending - Unit Costs

of items of investments approved

by National Bank

Please refer to our circular letter No.NB.DPD.FS/3602/IRDP-4/1994-95 dated 14 February 1995 on the above subject (copy enclosed for ready reference). It may please be observed therefrom that the unit cost as approved by NABARD may be treated as indicative cost only and banks are at liberty to vary the cost wherever necessary, to any extent, depending upon the local conditions and merits of each case. Despite clear instructions in this regard, it has been brought to our notice during the seminars/workshops conducted by us in the case of development of minor irrigation projects as well as in certain other form participated by NABARD that the banks still follow rigidly the unit costs as approved by NABARD for various investments. It is once again

reiterated that the unit costs approved by NABARD are only indicative costs and banks may evolve a mechanism under which they may ensure that the borrower is able to acquire the quality asset with the loan amount, subject to the generation of adequate repaying capacity and other relevant factors. Accordingly, you may kindly issue instructions to all the operating units in this regard.

Kindly acknowledge receipt.

Yours faithfully

( K. G. SHASTRY )

Chief General Manager

Annexure V

FINANCIAL ANALYSIS OF AGRICULTURAL PUMPSETS

Assumptions

1. Location : Wardha Dist., Maharashtra

2. Command Area : 1.2 ha

3. Type of Pumpset : Diesel Pumpset

4. Horse Power of Pumpset : 5 HP

5. Cost of Pumpset : Rs.15,500/- including cost of transportation and installation

6. Cost of operation per year : Rs.13,478/-

(including maintenance)

A. Pre Development Income

Sr.

No.

Crop Area

(ha)

Yield

(Qntl./ha)

Price

(Rs./Qntl.)

Gross Value of Produ-

Cost of Culti-

vation

Total Cost of culti-

Net Income

(Rs.)

ction

(Rs.)

(Rs./ha)vation

(Rs.)

1Bajra (HYV)

0.8 25 550 11,000 4,200 3,360 7,640

2Cotton (HYV)

0.4 18 1,550 11,160 10,000 4,000 7,160

3Wheat (HYV)

0.4 30 750 9,000 9,000 3,600 5,400

4Gram (HYV)

0.2 24 1,200 5,760 8,500 1,700 4,060

Total 36,920 12,660 24,260

Less :

Land Revenue @ Rs.50/- ha : Rs. 60/-

Interest on Short Term Loan : Rs. 3,125/-

Operation & Maintenance cost

(A pair of bullock, mhot@ Rs.25/- per day) : Rs. 9,125/-

Total : Rs.12,310/-

Net Surplus : Rs.11,950/-

B. Post Development Income

Sr.

No.

Crop Area

(ha)

Yield

(Qntl./

ha)

Price

(Rs./

Qntl.)

Gross Value of Produ-

ction

(Rs.)

Cost of Culti-

vation

(Rs./ha)

Total Cost of culti-

vation

(Rs.)

Net Income

(Rs.)

1Jowar (HYV) 0.8 30 700 16,800 6,200 4,960 11,840

2Cotton (HYV) 0.4 20 1,550 12,400 10,000 4,000 8,400

3Wheat(HYV) 0.6 35 750 15,750 9,000 5,400 10,350

4Vegetables 0.2 185 250 9,250 9,250 5,000 4,250

Total 2 270 3,250 54,200 19,360 34,840

Less :

Land Revenue @Rs.50/ha : Rs. 60/-

Interest on Short Term Loan : Rs. 5,000/-

Net Surplus : Rs.29,780/-

Incremental Income : Rs.17,830/-

Internal Rate of Return

Assumptions

1. Economic life of Pumpset : 9 years

2. Full income from investment from the first year onwards

3. No delay in energisation of pumpset

4. Investment is assumed in zero year

Cash Flow Statement

(Rs.)

NPW @15% : 4579.1

IRR : 24.04%

NAbard Model Bank Projects

Documents

multiply foregoing

automatic

genuine spare

total dissolved

bis certification

diesel oil

minor irrigation

detailed contour