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Tungabhadra Project: Gravity Based Micro Irrigation

Several agencies and researchers have thoroughly studied theproblems facing the TBP command area over the years. Tail-end

deprivation is well known and well documented as huge tracts of commandarea in tail-end is deprived of irrigation water and have low productivity.About 40% of the tail-end areas suffer from either full or partial waterdeprivation leading to low agricultural productivity. In addition, an estimated96,215 hectares is affected by water logging, salinity, alkalinity as per theAnnual Report: 2009-2010 of the Command Area Development Authority,Tungabhadra Project, Munirabad, thereby causing reduced cropproduction.

A number of approaches were adopted over the decades to solvethese problems, for example, lining the canals with precast slabs,participatory irrigation management (PIM), formation of Water UsersCooperative Societies (WUCS), cement concrete lining with a estimatedcost of Rs 1,844 Crores (as per the Detailed Project Report ofModernization of Canal System of Tungabhadra Project, 2011-12) from2008-9 onwards. However despite all these intervention there is marginalimpact on deprivation and large parts remain without irrigation water. Asthe irrigation duty is only 0.42 lps/ha in the entire TLBC command andmuch worse for most of the command area, there is just not enough water

with the conventional methods for farmers to grow financially attractivecrops. There is clear need to adopt effective solutions and new technology.

Gravity Based Micro Irrigation Concept: Gravity based Micro-irrigationtreats the potential head available because of unique topographicalfeatures as a useful natural resource in addition to the quantity of water.Both of these natural resources- water quantity and potential head, arepreserved and supplied through pipelines to agricultural fields in the form ofpressurized pipe flow, suitable for micro-irrigation, to fulfill the irrigation

water needs of the command area. There is possibility of covering about80% of command area through this method. In view of the prevalentsituation adoption of gravity based micro-irrigation at large scale remains apotential solution that can fulfill the water needs of the existing culturablecommand area and can also expand it, by covering non-irrigated areaswithin the Gross Command Area.

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Major Pipeline Projects:The Goldfields Water Supply Scheme: The scheme was designed andbuilt under the supervision of CY O'Connor between 1898 and 1903 topump fresh water from the Darling Range near Perth 560 km east to the

arid Goldfields. The scheme was designed with eight separate sections toovercome the difficulty of pumping water uphill over such a great distance.A dam, the pipeline and eight pump stations were the main components ofthe scheme. Cost of scheme was 2,655,220, ($5,310,440) in 1903,Number of pipes used 60,000, Amount of water 5.6 million gallons daily,(25.5 million kilolitres).Pipeline:The pipes were made of steel plates imported flat from Germanyand America. Two steel plates were bent to form semi-circles and joinedusing the innovative locking bar system invented by Mephan Ferguson.The locking bar replaced the practice of riveting the plates together. This

new system minimized the risk of leakage as no holes were drilled into thepipes and it also reduced internal friction as there were no rivet heads toslow the flow of water inside the pipes. Where possible the pipeline wasbuilt alongside the route of the existing railway line to enable the pipes tobe easily transported. The length of the train carriages determined thelength of the pipes (28 feet or 8.5 metres). The pipes were laid in trenchesto reduce contraction and expansion caused by temperature extremes.Lengths of pipe were joined as they were laid using a process that packedthe joint with lead, known as caulking. Over 60,000 joints were required

and this process was done by hand until a caulking machine that producedconsistent joints and saved time and labour was invented.Mundaring Weir: A dam, known as Mundaring Weir, was built on theHelena River to store water to be pumped to the Goldfields. O'Connor'sassistant, TC Hodgson considered 17 sites before choosing this one. In1898, during the excavation of the weir foundations, a huge boulder wasunexpectedly revealed. When it was removed a deep fault in the bedrockwas found. Overcoming these problems delayed construction for one year.The concrete wall was completed in June 1902. A construction camp onthe site was home to around 300 workers and their families during the

building of the weir.

The Wimmera Mallee Pipeline Project: The Wimmera Mallee PipelineProject (WMPP) is the largest water infrastructure project in Australia,replacing 18,000 kilometres of inefficient earthen channel with 9,159kilometres of pressurized pipeline and associated structures. Constructionof this great engineering feat commenced in November 2006 with the last

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pipe being laid in April 2010 - well ahead of the ten year timeframeoriginally proposed and within the $688 million project budget. Officialopening of the Wimmera Mallee Pipeline took place on 15 April 2010. Thepipeline project is supplying water to 36 towns and over 7,000 ruralcommunities with high quality and reliable water supply.

Virginia Pipeline Scheme: This scheme in Northern Adelaide Plains,South Australia was Completed in 1999. This waste-water reuse schemeincludes 150 km of pipeline distribution network to supply recycled water to200 square kilometres of horticultural land. The Virginia Pipeline projectwas one of the first of its type in South Australia, and consequently, asimilar scheme has been completed, south of Adelaide. This schemePlays a significant role in reducing pollution into marine environment by70%. Provides opportunity to secure access to water, a particularly limited

resource in the context of a semi-arid climate where existing groundwaterresources were facing overuse. Provides about 250 vegetable growerswith reliable supply of water, to a quality suitable for irrigation use.Estimated volume of recycled water is 22,500 ML per year whichrepresents over 50% of annual plant flow. (Source: Kracman, Martin, &Sztjanbok, 2001)

Northern Mallee Pipeline: This project in Northern Mallee, Victoria wasCompleted in 2002. The project makes provision of an alternative water

distribution system: Conversion of earthen channels to 2500 km pipelinesfor stock and domestic water supply system in agricultural region. Projectcommenced in 1991 and completed 2002. It has several benefits such as:Security of water supply on farms for stock, and increased, effectiveness ofpesticides & spray units, Increased flexibility of water systems on farms,Increase productivity of land through channel decommissioning, Improvedquality of farm life and increased financial security. Estimated volume ofwater recovered is 50, 000 ML per year. The project also helps in increasedenvironmental flows with an allocation of 34,000ML per year. (Source:WIDCORP, 2006)

The Tungamah Pipeline- Lake Mokoan project: The project situated nearBenalla, Victoria was completed in 2006-07. A water recovery schemeinvolving decommissioning of Lake Mokoan and installation of 360km ofpipelines to replace 520km highly inefficient earthen channels. TheTungamah pipeline links the Tungamah domestic and stock system

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between Shepparton and Yarrawonga. The project envisages to providereliable water supply to irrigators. Estimated volume of water recovered is18,000 ML per year for environmental flows to the Snowy River. Also helpto restore flows to Broken and Goulburn Rivers.

Performance of Micro-Irrigation Schemes

Several pilot projects have been taken up in Karnataka and other parts of

India during last two decades. Performance of these projects demonstrates

efficacy, efficiency and effectiveness of micro irrigation systems. However review

and study of the existing pilot projects on micro irrigation indicates that not only

the technology has been fully demonstrated but also reasonably large pilot

projects have been successfully completed. Some of these schemes are reviewed

below:

Shiggaon Lift Irrigation Scheme: Shiggaon Lift Irrigation Scheme isproposed to irrigate 9900 ha dry lands in 30 villages of Shiggaon, Savanurand Hanagal Taluks in Haveri district. The villages coming under thisscheme are poverty offended drought area. Agriculture is the economicactivity of the Haveri district. Low annual rainfall of the order of 532 mmcoupled with large variance in annual rainfall and uncertainty within a yearcauses the agriculture a risky venture. Hence the proposed schemeenvisages diversion of 42.45 M. Cum (1.5 TMC) of water by constructing a

diversion weir across Varada River near Halasur village of Savanur taluk,Haveri district, lifting of water to higher lands and providing SprinklerIrrigation facility. Thus providing irrigation and stabilizing the agriculturalproduction and improving per capita income and standard of living of thepeople.

Shiggaon LIS is proposed to irrigate dry lands in villages of Shiggaon,Savanur and Hanagal taluks of Haveri district. The Jackwell is located atLongitude 75017'00?E and Latitude 140 51'00?N near Halasur village ofSavanur Taluka. The project site (Head works) is approachable by Roadand is at a distance of 21km along NH-4 from Shiggaon, the Taluk headquarters. The total water allocated for the proposed project is 42.45 M.Cum(1.5 TMC) but the current utilization of water for the proposed project is31.696 M.Cum (1.12 TMC) by adopting Sprinkler Irrigation with pipedconveyance system as suggested by EAC, MoEF and thereby saving 10.77M.Cum (0.38 TMC) of water. Further, the quantum of saved water will beutilized for irrigating balance area through sprinkler irrigation at later stages.

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The scheme also envisages construction of 6 Bandaras and to providedrinking water facility and sub soil replenishment by filling of existing MItanks with in the command area. The proposed project doesntenvisagedisplacement of the families/houses for the project activities. The total landrequired for the project is 45 ha which is dry in nature and will be acquiredas per Land Acquisition Act, 1894. Land resources conservation achievedis 94%. The total cost of the project is ` 238 Crores and the Benefit costratio is 1.28.

AP Micro Irrigation Project (APMIP):After successfully completing pilot projects,

Andhra Pradesh has taken up micro irrigation at large scale having an area of 1.5

lakh acres under Andhra Pradesh Micro Irrigation Project (APMIP). Plans and

survey number wise details for an ayacut of about 80,000 acres in Alimineti

Madhava Reddy Project (AMR Project) under packages 77, 78, 79, 80 and

Distributary Nos.16 & 7/A are furnished to Andhra Pradesh Micro IrrigationProject (APMIP) authorities for implementation of Micro Irrigation by Kharif in

2007. The above area has been allocated to 11 M.I companies by the APMIP

authorities. For the entire ayacut of 2 lakh acres developed under the lift

irrigation projects of Pulivendula Branch Canal, Lingala and Gandikota in

Rayalaseema region, use of micro-irrigation systems such as sprinklers and drips

has been made mandatory. As in the case of other lift schemes, the government

of A.P. has taken a policy decision to make sprinklers and drips a must for the

farmers of these three lift schemes to ensure optimum utilisation of the scarcely

available water.

Government of A.P. estimates that under micro-irrigation system one tmcft

(thousand million cubic ft) of water can irrigate 15,000 acres instead of 10,000

acres under traditional system. It also clarified that all the ayacut under these

three lifts would switch over to micro-irrigation systems from January 2009. The

AP Government announced 90 per cent subsidy purchase of micro-irrigation

systems and related equipments. The pilot micro-irrigation projects being

implemented under AMR Canal in Nalgonda and Pulivendula Branch Canal in

Kadapa were considered successful.

All India Experience: A number of pilot projects as well as full scale micro

irrigation projects are implemented all over India. These projects have invariably

resulted in success on the basis of a number of parameters. Evaluation Study of

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Centrally Sponsored Scheme on Micro Irrigation, Conducted by NABARD

Consultancy Services Private Limited, (NABCONS), March 2009 are as follows:

1)

Major impact of drip irrigation was found tobe crop diversification.

2)

Savings of irrigation water due to sprinkler was found to vary from 40 to 65percent for horticulture crops, ground nut and cotton it was 35-40 percent

and for vegetables it was 30 to 47 percent.

3)

Adoption of micro irrigation resulted in significant reduction of labour

(irrigation, weeding, harvesting) and aided convenience by eliminating

drudgery in form management.

4) Savings in irrigation water due to micro irrigation resulted in directly

reduction of power consumption.

5) Adoption of micro irrigation resulted in significant increase in yields in all

major crops. The impact of micro irrigation technology on yield waspervasive.

6)

Micro irrigation technology also reported by the beneficiaries to have

resulted in improved quality of produce and therefore resulting in

realization of higher prices.

7)

Gross Value of Produce (GVP) per hectare increased with adoption of micro

irrigation, which varied from crop to crop and state to state.

Internationally there are several success stories including that of Israel which has

over 50% of total area under micro irrigation. At this stage it is possible to adopt

the technology at large scale without any need for taking up another pilot project,

as the technology has been amply demonstrated and also successfully working for

last several decades.

Tungabhadra Project: Gravity Based Micro-Irrigation: TLBC Bed Level at Off-take Sluice is +472.44 m and at Tail-end +362.02 m. Thus a potential headof 110.42 m (363.40 Feet) is available along the Main Canal itself. Inaddition there are bed level differences of about 50-70 meters along thedistributaries. For example D-36 has +433.75 m total head at offtake and

+384.44 m at tail-end. Thus 49.31 m additional head is available along D-36. Further potential head becomes available along the minors.Tungabhadra Reservoir Project command area thus offers a uniqueopportunity in view of its topographical features in combination with suitablecanal hydraulic particulars, making it possible to convert open channelbased irrigation system into gravity based pressurized pipe flow systemsuitable for micro irrigation like drip and sprinkler in large portion of the

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command area, without any need for electric power and pumpingmachinery.

Upstream Pipeline: The system envisaged here consists of a Pipeline starting from

Bhoruka Reservoir located at Km 17 (Mile 10) on TLBC and moving South-East andsubsequently running parallel to Raichur Gangavathi State Highway. The Pipeline

extends upto D-36. Location of the pipeline is shown in google map below:

Design data for u/s Pipeline is as follows: The Pipeline has a length of 58.20 Km,

diameter 4.00 m, flow velocity 1.775 m/sec. and discharges 22.07 Cumecs (779.40

Cusecs) of water to irrigate 1,16,908 Acres Ayacut at a duty of 150 Acers per

cusecs. The Pipeline intake has +474.77 m total head and exit elevation is +393.00

m, thus a potential head of 81.77 m (268.27 Feet) is available along this Pipeline.

The pipe flow calculations are made using Hazen-William Equation with a friction

factor of 141 for concrete pipes of diameter larger than 1.20 m. Ground levelprofile along the Pipeline alignment is also shown in the above figure. Calculation

results are shown in figures below:

U/s Pipeline: Ground Level Profile:

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U/s Pipeline- Dynamic Pressure Head:

471

452445443444

449

437438

454454445

412416

404403

417424

417

403407

415425

414424

412414

402407407

394393

380

400

420

440

460

480

0 10 20 30 40 50 60

GroundLevelinm

Distance in m

Pipeline_us Gound Level

4

2228 29 28

22

33 31

14 14

22

5449

61 61

4739

46

6055

47

37

48

38

49 47

5954 54

6768

0

10

20

30

40

50

60

70

80

0 10 20 30 40 50 60

PressureHeadinm

Distance in m

Pipeline_us: Dynamic Pressure Head

4

2330 32 31

26

38 37

21 21

30

6359

71 72

5851

58

7268

60

50

61

51

63 61

7368 68

8182

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60

PressureHeadinm

Distance in m

Pipeline_us: Static Pressure Head

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Sub-Distributary From Upstream Pipeline: This Pipeline is selected to

demonstrate that in worst case scenario also enough pressure head is available.

The Pipeline has a length of 14.00 Km, diameter 0.90 m, flow velocity 1.50 m/sec.and discharges 0.945 Cumecs (33.33 Cusecs) of water to irrigate 5,000 Acres

Ayacut at a duty of 150 Acers per cusecs. The Pipeline intake has +461.374 m total

head and exit elevation is +434.00 m, thus a potential head of 27.374 m (89.81

Feet) is available along this Pipeline. The pipe flow calculations are made using

Hazen-William Equation with a friction factor of 141. Ground level profile along

the Pipeline alignment is also shown in the above figure. Calculation results are

shown in figures below:

0.00

0.20

0.40

0.60

0.80

1.00

0 10 20 30 40 50 60

HeadLossinm

Distance in m

Pipeline_us: Head Loss

393398

407413 413 414

417422

427423 423 426

434 435 434

345355

365

375

385

395

405

415

425

435

445

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

GroundLevelinm

Distance in Km

US_PIPE_SD: Ground Level

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6862

5246 45 44

4035

2933 33

30

22 21 22

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

PressureHeadinm

Distance in Km

US_PIPE_SD: Dynamic Pressure Head

68

6354

48 48 4744

3934

38 3835

27 26 27

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

PressureHeadinm

Distance in Km

US_PIPE_SD: Static Pressure Head

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

HeadLossinm

Distance in Km

US_PIPE_SD: Head Loss

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Downstream Pipeline: Another major pipeline is proposed from KM 167.372

(Mile 106.50) towards Tungabhadra River in the South-East Direction as shown in

the figure below. The Pipeline intake is just upstream of balancing reservoir and

as well as canal drop.

The Pipeline has a length of 35 Km, diameter 4.00 m, flow velocity 1.50 m/sec.

and discharges 18.57 Cumecs (656 Cusecs) of water to irrigate 1,31,221 AcresAyacut at a duty of 200 Acers per cusecs. The Pipeline intake has +419 m total

head and exit elevation is +369.00 m. The pipe flow calculations are made using

Hazen-William Equation with a friction factor of 141 for concrete pipes of

diameter larger than 1.20 m. Ground level profile along the Pipeline alignment is

also shown in the above figure. Calculation results are shown in figures below:

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0

10

20

30

40

50

60

70

0 5 10 15 20 25 30 35 40

PressureHea

dinm

Distance in Km

PIPE-DS: Pressure Head

350

360

370

380

390

400

410

420430

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

GroundLevelinm

Distance in Km

PIPE-DS: Ground Levels

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The main conclusion can be drawn from above calculations that just beyond 5 Km

head reach of this Pipeline, there is about 10-15 meters pressure head is

available. Dynamic pressure head reaches upto 60 m and static head upto 63 m. It

can also be seen that the Pipeline passes through the undulating ground and it is

possible to refine the alignment after detailed survey and contour maps are

prepared. Also, the results indicate that there is enough pressure head available

above the hillocks and all the high grounds and hillocks can be covered under this

system. This offers an opportunity that entire gross command area can be

brought under pressurized pipe flow irrigation.

Pipeline D-36:This calculation is made to demonstrate that the concept of gravity

based micro-irrigation can be applied to individual distributaries also as entirely

independent system. This also offers opportunity for phased implementation of

this concept.

0

10

20

30

4050

60

70

0 5 10 15 20 25 30 35 40

PressureHeadinm

Distance in Km

PIPE-DS: Static Pressure Head

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The Pipeline has a length of 39.010 Km, diameter 3.00 m, flow velocity

1.272 m/sec. and discharges 8.95 Cumecs (316.23 Cusecs) of water to irrigate

47,434 Acres Ayacut at a duty of 150 Acers per cusecs. The Pipeline intake has

+433.75 m total head and exit elevation is +384 m. Thus the Pipeline has a

potential head of 49.75 m (163.22 Feet). The pipe flow calculations are made

using Hazen-William Equation with a friction factor of 141 for concrete pipes of

diameter larger than 1.20 m. Ground level profile along the Pipeline alignment isalso shown in the above figure. Calculation results are shown in figures below:

345

355

365375

385

395

405

415

425

435

445

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

GroundLevelinm

Distance in Km

D-36: Ground Level

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12 1 1 2

7 7

13 13

20 22 22

25

24

2826

27 2829

33

42 4037 36

3935

42

31

3834

3033 33

25

3234

0

5

10

15

20

25

30

35

40

45

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

PressureHea

dinm

Distance in Km

D-36: Dynamic Pressure Head

0

1

1

2

2

3

3

4

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

PipeDiameterinm

Distance in Km

D-36: Pipe Diameter

1 3 2 2 39 9

15 1623 25 26

30 2934 32 34 35

3741

51 50 4848 51 4855

45

5656 5560 62

65

7984

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

PressureHeadinm

Distance in Km

D-36: Static Pressure Head

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Calculation results clearly indicate that over 10 m pressure head is available at 8

Km from Distributary Off-take. Maximum head available reaches upto 42 meters.

Sub-Distributary 36/6:Additional head available is for Sub-Distributary 36/6. The

Pipeline has a length of 7.63 Km, diameter 1.10 m, flow velocity 1.000 m/sec. and

discharges 0.944 Cumecs (33.33 Cusecs) of water to irrigate 5,000 Acres Ayacut at

a duty of 150 Acers per cusecs. The Pipeline intake has +422.445 m total head and

exit elevation is +364.000 m. Thus the Pipeline has a potential head of 58.445m

(191.75 Feet). This is much larger than D-36 head 49.75 m (163.22 Feet).

386390 391

388 388

382

370374

364

345

350

355

360

365

370

375

380385

390

395

1 2 3 4 5 6 7 8 9

GroundLevelinm

Distance in Km

D-36/SD6: Ground Level

3631 30

32 32

37

4945

55

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9

PressureHeadinm

Distance in Km

D-36/SD-6: Dynamic Pressure Head

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The main conclusion can be drawn from above calculations that just beyond 8 Km

head reach of this Pipeline, there is about 10-15 meters pressure head is

available. It can also be seen that the Pipeline passes through the undulating

ground and it is possible to refine the alignment after detailed survey and contour

maps are prepared. Also, the results indicate that there is enough pressure head

available above the hillocks. This offers an opportunity that entire gross command

area can be brought under pressurized pipe flow irrigation.

Small Scale Gravity Based Micro-Irrigation: Conditions and requirements forlarge scale schemes described above are completely different from small scale

schemes considered here. A number of potentially promising locations are

available on TLBC system suitable for Small Scale Gravity Based Micro-Irrigation.

These locations offer unique geographical features of the command area in

combination with suitable canal hydraulics, making it possible to convert open

channel based irrigation into gravity based pressurized pipe flow suitable for

micro irrigation like drip and sprinkler, without any need for electric power and

pumping machinery. For example, just downstream of Bhadruka Reservoir and

Hydel Power Station there is a small command area that can be completelyconverted to pressurized flow on pilot basis, as 17.85 meters head is available.

Additionally between Km. 0.00 to 30 many places offers suitable conditions. Other

potential locations are three mini Hydel Power Stations at Sirwar (Km. 174.00)

with 9.37 Meters head, Ganekal (Km. 182.00) with 11.66 Meters head and

3632 31

34 3440

5248

58

0

10

20

30

40

50

60

70

1 2 3 4 5 6 7 8 9

PressureHeadinm

Distance in Km

D-36/SD-6: Static Pressure Head

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Kalmala (Km. 199.00) with 7.62 Meters head appear to-be suitable sites and may

be taken up on pilot basis.

For the purpose of feasibility study for small scale schemes, location of

Bhoruka Reservoirs offers suitable conditions. Here Distributaries No. 9, 10 and10A have command areas of 675, 183 and 563 Acres respectively. These

distributaries have designed discharges of 25.12, 12.53 and 20.00 cusecs

respectively and duties of 27, 15 and 18 Ac/Cusecs respectively.

Pipeline D9_D10_D10A: This Pipeline takes off from Bhoruka Reservoir located at

Km 17 (Mile 10.00) of the Tungabhadra Left Bank Main canal. The Pipeline

replaces Distributaries No. 9, 10 and 10A, those have very high water

consumption as their duties are only 25.12, 12.53 and 20.00 Acers/Cusecs

respectively. Length of the Pipeline is 6.75 Km and initial diameters 0.90 m (3

Figure 4: downstream of Bhadruka

Power Station there is small

command

area that can completely

converted to pressurized flow on

pilot basis.

Figure x: Areas near Three mini

Hydel power stations at Kms. 174,

182 and 199 With Available Head of

9.37, 11.66 & 7.62 Meters Head offer

suitable sites for gravity based

pressurized Micro Irrigation.

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Feet) from Km 0.00 to Km 4.00, and 0.60 m (2 Feet) from Km 4.00 to Km 6.75. The

Pipeline has a duty of 50 Ac/Cusecs, discharge 0.8046 Cumecs (28.42 Cusecs), and

ayacut 1421 Acres.

458 458452

447 444 444 442433

345

365

385

405

425

445

465

1 2 3 4 5 6 7 8

GroundLevelinm

Distance in Km

D9_D10_D10A: Ground Level

17 16

21

26 27 2628

37

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8

PressureHeadinm

Distance in Km

D9_D10_D10A Dynamic Pressure Head

17 17

2328

31 31 33

42

0

10

20

30

40

50

1 2 3 4 5 6 7 8

PressureHeadinm

Distance in Km

D9_D10_D10A: Static Pressure Head

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Indicative Estimate:

U/s Pipeline including Rs 500 Crores.

Full TLBC Command: Rs. 2,000 Crores

Cost of per Acre: Rs. 40,000/-

Gross Command Area: 7,50,000 Acres

Localized Area: 6,05,000 Acres

New Irrigated Area: 1,20,000 Acres

Conclusions: These gravity based systems potentially offer several advantages

over the present flood irrigation system. Gravity based flow is highly reliable asthere is no need for electricity, which is very irregular. Gravity based system is

cheap as there is no need for expensive electricity and hence no energy cost. Lowcapital cast for gravity based systems as no electrical motors, pumping sets etc.

Low maintenance cost as no machinery is required. Very robust and reliablesystem as it has fever moving parts. Potentially huge saving (40 to 60%) in scarce

water resources. Accurate volumetric measurements becomes practical andfeasible. Water logging problem can be avoided as there is controlled water

application. Soil salinity problems can be avoided. Formers can enjoy assured

water supply and improve their productivity and diversification for achievingeconomic prosperity. Farmers can enjoy flexibility in water use and can use this

flexibility to produce economically and commercially attractive crops. The system

completely eliminates rigidity of timing, quantity and method of water availability.Completely avoids the need for expensive soil reclamation and subsoil drainage.

Only possible way to convince the head reach water users to willingly agree toreduced water consumption because this makes economic sense.

Objectives for gravity based micro irrigation system may be listed as below:

Gravity based Micro-Irrigation Systems uses Natural Topographical Situations.

Complete Adoption of Volumetric based Water Supply. Introducing flexibility in

Water Availability to Individual Water Users. Fixed Quota of Water allocated with

full freedom to use it as per their best needs. Prevent the need for drainage of

polluted standing water and avoid fresh water supply.

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Tranche 1: The following works are suggested tobe taken up in Tranche 1, in view

of very tight time schedules and other constraints:

1)

Bhoruka Small Scale Gravity Based Micro-Irrigation.

2)

Further investigations and topographical survey for large scale schemes.

3)

Preparation of Detailed Project Reports.

4)

Preparing documentations for obtaining permissions from Central Water

Commission etc.

Dr M K Khaishagi,

Irrigation, O&M Engineer

26th

May 2012.