2. What is Command Area, Why Command Area Development, Water Conveyance System & Irrigation Structures By C. K. S. Parmar Retd. Chief engineer, Specialisations: Command Area Development, Watershed Development and Soil Conservation, Government of Rajasthan

3. INTRODUCTION After Independence the Government of India launched a countrywide programme of multipurpose river valley projects to make use of unharnessed water resources in the country. The purpose of the scheme was to generate hydroelectric power and to supply water for irrigation. The culturable area which can be irrigated by a particular command are may be defined as the culturable command area (CCA) irrigated by that reservoir/dam. The total area covering home state area, roads, houses, barren land, and uplands coming under that command are added with C.C.A. may be known as gross command area. In rural development the construction and maintenance of CAD works can be given top priority because the area on one side will provide employment to the needy rural masses and on the other hand it will provide better irrigation and drainage facilities which will improve the socio economic conditions of the farmers and generate livelihood.

4. i.Minimization of water losses through lining of canals, increasing canal capacity, installation of control structure, the teaching improved technique for more efficient water use etc. ii.The maximization of grains from water use through on farm development works, the construction of an improved and wider road network, improved agriculture techniques brought by adaptive research and agriculture extension etc. iii.The equitable distribution of water throughout the command area and greater control over canal system as a whole. iv.The most important aspect of CAD works to save the most valuable water and increase optimum crop production per unit of water and per unit of area.

6. DETAILS OF CONCERNED GUIDELINES

8. There is a gap between the irrigation potential created and utilised. Many of the irrigation projects in the country have also been under operation below their scheduled potential due to in adequate maintenance, which is one of the important factor for reduced irrigation efficiency at project level. This has resulted in the problem of low efficiency of the water use and low productivity. Increasing trend of water logging, salinity and alkalinity is offsetting the advantages of irrigation by rendering the affected areas unproductive or under productive. The process of reclamation is very slow with the result an additional area becoming water logged saline/ alkaline. Therefore for integrated development of Command area the convergence if MGNREGA with the schemes of Ministry of water resources and schemes of MOA for gap filling and value addition should be made. Therefore the convergence of CAD and MGNREGA will be mutually beneficial.

9. In few Commands the OFD works (Full package) have been done where as in other command areas only water courses have been constructed. The water courses are also not constructed in the complete command that can be done by MGNREGA funds, so that water incomplete designed command can be made available. And where the water courses are not maintained there the maintenance can be done under MGNREGA.

15. The Water Conveyance System in any command area mainly comprises a reservoir, where the water is stored for irrigation in a dam. Thereafter, water goes to the field of a farmer through Main canal, Branch canal, Distributary canal, Minor and Watercourse.

21. Cross-Section A typical cross section of watercourse is given below-

22. Typical X-section of earthen levee of watercourse

23. Typical Cross Section of Earthen Watercourse

28. Typical Cross Section of Earthen watercourse showing details of dressing area

31. Figure 3-6: Cross Section of Earthen Levee and Section Cutting

33. Cross Section of Watercourse – Cement Concrete

34. S.No.Name of ItemLengthWidth Height/ Depth Quantity 1Dag belling 7.5 cm to 10 cm deep1.00 2 Cutting & clearanceof jungle, bushes,shrubs Ankara/Ipomoea, Julie flora typha etc. on canals and bunds in dry/moist/slushy conditions including disposal 1.004.28-4.280 3 Earth work in excavation including loading, unloading, disposal and dressing of excavated earth within initial lead of 100m and lift up to 1.5 m in dry or moist soil including dressing of excavated area With cost of dewatering wherever required, and all applicable taxes and levies etc. Complete in all respect. 1.003.630.4251.540

35. S. No.Name of ItemLengthWidth Height/ Depth Quantity 4 Earth work in excavation including loading, unloading, disposal and dressing of excavated earth within initial lead of 100m and lift up to 1.5m in dry or moist including dressing of excavated area With cost of dewatering wherever required, and all applicable taxes and levies etc. Complete in all respect. 1.000.830.3250.270 5 Supplying and laying sand in required profile including all lead & lifts. 1.001.340.050.070 6 Cement concrete(1:3:6) well mixed and laid in position complete including all leads of all construction materials including curing and finishing having well graded crusher broken stone aggregate of maximum size up to 20 mm. 1.001.2400.080.090 7Wire Mesh1.00 1.000

36. S.No.Name of ItemLengthWidth Height/ Depth Quanti ty 8 Plaster in cement sand mortar 1:4 including racking of joints, smoothfinishing& curingetc. Complete including allleadsof constructionmaterials; of thickness: 12mm. Inner1.00 1.142.280 Outer1.00 0.100.200 Total 2.480 Total Add Contingency 3 % Grand Total

37. Cross Section of Watercourse – Stone Masonry

38. S. No. Name of ItemLengthWidth Height/ Depth Quantit y 1Dag belling 7.5 cm to 10 cm deep1.00 2 Cutting & clearanceofjungle, bushes, shrubs Ankra/Ipomoea, Julie flora typha etc. on canals and bunds in dry/moist/slushy conditions. 1.004.00 4.000 3 Earth work in excavationincluding loading, unloading, disposal and dressing of excavated earth within initial lead of 100m and lift up to 1.5m in dry or moist including dressing of excavated area with cost of dewatering wherever required, and all applicable taxes and levies etc. Complete in all respect. 1.001.300.2250.290

39. 4 Supplyingandlayingsandinrequired profile Including all leads & lifts. 1.001.300.050.070 5 Cement concrete (1:4:8) M‐7.5 well mixed and laid in position complete including all leads of all construction materials including curing and finishing having well graded Crusher broken stone aggregate of maximum size up to: 20mm. 1.001.300.0750.100 6 Random rubble stone masonry (using R.R. stones where 75% stones to be not less than 15 cm in size in any direction and weighing not less than 23 Kg.) for super structure including curing all leads of construction materials,&all taxes and with initial lift / de‐lift of 5m from ground level etc. complete in cement sand mortar 1:6 1.000.3000.300.180

40. 7 Cement concrete (1:2:4) well mixed and laid in position complete including all leads of all construction materials including curing and finishing having well graded crusher broken stone aggregate of maximum size up to: 20mm. 1.000.4000.050.020 8 Plaster in cement sand mortar 1:4 including racking of joints, smooth finishing & curing etc. complete including all leads of construction materials ; of thickness: 12mm. Inner1.00 0.250.500 Outer1.00 0.200.400 Total 0.900

41. 9 Providing andlaying cement concrete coping in (1:2:4) with maximum size of crusher broken aggregate up to 20mm, including shuttering etc. with all leads of material complete in all respect in thickness of : 50mm. 1.000.324 0.650 10 Re‐handling ofexcavated material including loading nloading and dressing within initial lead of 100m and lift 1.5m With cost of dewatering wherever required and all applicable taxes and leveies etc. complete in all respect. Quantity as per Item no ‐1 0.290 Total Contingency charges @ 3 % Grand Total

42. Cross Section of Watercourse - Brick:

43. S. No. Name of ItemLengthWidth Height/ Depth Quantity 1Dag belling 7.5 cm to 10 cm deep.1.00 2 Cutting & clearance of jungle, bushes, shrubs Ankra/ Ipomoea, Julie flora typha etc. on canals and bunds in dry/ moist/ slushy conditions including disposal. 1.004.00 4.000 3 Earthworkinexcavation including loading, unloading, disposal and dressing of excavated earth within initial lead of 50m and lift up to 1.5m in dry or moist including dressing of excavated area with cost of dewatering wherever required, and all applicable taxes and levies etc. complete in all respect. 1.001.150.2250.260

44. S.No.Name of ItemLengthWidth Height/ Depth Quantity 4 Supplying and laying sand in required profile including all lead & lifts. 1.001.150.050.060 5 Cementconcrete(1:4:8) M‐7.5 well Mixed and laid in position complete including all leads of all construction materials including curing and finishing having well graded Crusher broken stone aggregate of maximum size up to: 20mm. 1.001.150.0750.090 6Brick Masonry1.000.2250.300.140

45. S.No.Name of ItemLengthWidth Height/ Depth Quantity 7 Cementconcrete(1:2:4) M‐15 well mixed andlaidin position complete including all leads of all construction materials including curing and finishing having well graded crusher broken stone aggregate of maximum size up to: 20mm. 1.000.4000.050.020

46. S.No.Name of ItemLengthWidthHeight/Depth Quant ity 8 Plasterincementsandmortar1:4 includingrackingofjoints,smooth Finishing&curingetc. Complete includingallleads of construction materials; of thickness: 12mm. Inner1.00 0.250.500 Outer1.00 0.200.400 Total 0.900

47. 9 Providing and laying cement concrete coping in (1:2:4) with maximum size of crusher broken aggregate up to 20mm, including shuttering etc. with all leads of material complete in all respect in thickness of : 50mm. 1.000.249 0.500 10 Re‐handlingexcavatedmaterial Including loading unloading and dressing within initial lead of 50m. and lift 1.5m With cost of dewatering wherever required, and all applicable taxes and levies etc. Complete in all respect. Quantity as per Item no ‐1 0.26 Total Add Contingency @ 3 % Total