Service Contract No 2007 / 147-446 - Swaziland

Restructuring and DiversificationManagement Unit (RDMU)to coordinate the implementation ofthe National Adaptation Strategy tothe EU Sugar Reform, SwazilandService Contract No 2007 / 147-446EuropeAid/125214/C/SER/SZ: Restructuring andDiversification Management Unit to coordinate theimplementation of the National Adaptation Strategy to theEU Sugar Reform, SWAZILANDEC General Budget – SU-21-0603SWAZILAND Technical Audit of Farmers AssociationA s i h l u m i s a n e Far m e r s A s s o c i a t i o nSubmitted to:The Delegation of the European Commission to Swaziland4 th Floor Lilunga House, Somhlolo Road, Mbabane, SwazilandMinistry of Economic Planning and DevelopmentP.O. Box 602Mbabane H100, Swaziland

Your contact personswith GFA Consulting Group GmbH areDr. Susanne PecherAnke SchnoorRestructuring and Diversification Management Unit(RDMU)to coordinate the implementation of the National AdaptationStrategy to the EU Sugar Reform, SwazilandTechnical Audit of Farmers AssociationAuthors: Tiekie de Beer,Designer Member of the South African IrrigationInstitute (SABI)&Bongani BhembeMission ReportAddressGFA Consulting Group GmbHEulenkrugstraße 82D-22359 HamburgGermanyPhone +49 (40) 6 03 06 – 111Fax +49 (40) 6 03 06 - 119Email: afrika@gfa-group.deAsihlumisane Farmers Association Report - 2009Page ii

DISCLAIMERThe contents of this report are the sole responsibility of the RDMU and can in no waybe taken to reflect the view of the European Union.Asihlumisane Farmers Association Report - 2009Page iii

TABLE OF CONTENTSAsihlumisane Farmers Association ............................................................................................................. iTABLE OF CONTENTS ................................................................................................................................. ivLIST OF TABLES ............................................................................................................................................ viLIST OF FIGURES ......................................................................................................................................... viiLIST OF APPENDICES ................................................................................................................................ viiiABBREVIATIONS ........................................................................................................................................... ix1 INTRODUCTION ............................................................................................... - 1 -2 BACKGROUND ON IRRIGATION DEVELOPMENT ....................................... - 2 -3 TECHNICAL AUDIT REPORT .......................................................................... - 4 -3.1 REVIEW OF THE IRRIGATION DESIGN CRITERIA AND SPECIFICATIONS .....................- 4 -3.1.1 Irrigation Design Criteria and Specifications by consulting engineer ................................................- 4 -3.1.1.1 General Description of phase one Contract ................................................................................- 4 -3.1.1.2 Phase two Irrigation Design Criteria ..........................................................................................- 4 -3.1.1.3 System Pumping Station ............................................................................................................- 5 -3.1.1.4 River Pump Sets .........................................................................................................................- 5 -3.1.1.5 Irrigation Pump Sets ..................................................................................................................- 5 -3.1.1.6 Irrigation System ........................................................................................................................- 5 -3.1.1.7 Mainline, sub-mains and irrigation system layout .....................................................................- 6 -3.1.1.7.1 Mainline and sub-mains ........................................................................................................- 6 -3.1.1.7.2 Hydrants ................................................................................................................................- 6 -3.1.1.7.3 Laterals .................................................................................................................................- 6 -3.1.1.7.4 Pump control valve in booster pump station .........................................................................- 7 -3.1.1.8 Review of Contractor Irrigation Design Criteria and Specifications .........................................- 7 -3.1.1.8.1 Planning ................................................................................................................................- 7 -4 FIELD EVALUATION OF IRRIGATION SYSTEM .......................................... - 11 -4.1 Pumps and Pump Stations ..................................................................................................................- 11 -4.1.1 Pump Suction Side ............................................................................................................................- 11 -4.1.1.1 Suction Pipe Flow Rate ............................................................................................................- 11 -4.1.1.1.1 Requirements for Fittings ...................................................................................................- 12 -4.1.1.1.2 Suction Pipe Inlets ..............................................................................................................- 15 -4.1.1.1.3 Suction side losses ..............................................................................................................- 17 -4.1.1.1.4 Suction height .....................................................................................................................- 18 -4.1.1.2 Pump evaluation .......................................................................................................................- 19 -4.1.1.2.1 Pump Operation ..................................................................................................................- 20 -4.1.1.2.2 Power required on the pump shaft ......................................................................................- 20 -4.1.1.2.3 Pump Station General Evaluation .......................................................................................- 21 -4.1.2 Power Supply And Consumption .....................................................................................................- 23 -4.1.3 Supply System ..................................................................................................................................- 26 -4.1.3.1 Mainline size ............................................................................................................................- 26 -4.1.3.2 Mainline class ..........................................................................................................................- 27 -4.1.4 System capacity evaluation ...............................................................................................................- 27 -5 FIELD EVALUATION OF SPRINKLER IRRIGATION SYSTEM .................... - 29 -5.1.1 Sprinkler pressure .............................................................................................................................- 33 -Asihlumisane Farmers Association Report - 2009Page iv

6 ASSESSMENT OF OPERATION, MANAGEMENT AND MAINTENANCE OFTHE IRRIGATION SYSTEM .................................................................................. - 34 -6.1 Operation .............................................................................................................................................- 34 -6.2 Management Practices ........................................................................................................................- 36 -6.3 Maintenance Survey ...........................................................................................................................- 38 -6.4 HISTORY OF SYSTEM PERFORMANCE ....................................................................................- 39 -7 CONSTRAINTS TO EFFICIENT SYSTEM PERFORMANCE ........................- 41 -8 RECOMMENDATIONS ...................................................................................- 46 -9 CONCLUSION ................................................................................................- 49 -10 LITERATURE REFERENCES .....................................................................- 52 -11 PRODUCT INFORMATION .........................................................................- 54 -12 APPENDICES .............................................................................................- 60 -Asihlumisane Farmers Association Report - 2009Page v

LIST OF TABLESTABLE 1. PUMP AND MOTOR SPECIFICATIONS AND MEASUREMENTS CONDUCTED ON ALL PUMPS .............. - 20 -TABLE 2. SPRINKLER VALUATED BLOCK SUMMARY ........................................................................................... - 29 -TABLE 3.TECHNICAL PROPERTIES OF SPRINKLERS FOUND ON SITE AT 35M OPERATING PRESSURE ................ - 32 -TABLE 4.TECHNICAL PROPERTIES OF SPRINKLERS FOUND ON SITE AT 35M OPERATING PRESSURE ................ - 33 -TABLE 5. MAINTENANCE SCHEDULE FOR SPRINKLER IRRIGATION SYSTEMS ..................................................... - 38 -TABLE 6. MAINTENANCE PRACTICES IMPLEMENTED BY FA ............................................................................... - 38 -TABLE 7. PUMPS MAINTENANCE COSTS INCLUDING MAJOR BREAKDOWN REPAIR COSTS .............................. - 39 -Asihlumisane Farmers Association Report - 2009Page vi

LIST OF FIGURESFIGURE 1. RIVER PUMP STATION ALONG THE KOMATI RIVER ............................................................................. - 2 -FIGURE 2. BOOSTER PUMPS ................................................................................................................................. - 3 -FIGURE 3. SAPWAT SCREEN INDICATING WATER REQUIREMENT FOR SPRINKLER IRRIGATION WITH RAINFALLTAKEN INTO ACCOUNT .............................................................................................................................. - 10 -FIGURE 4. REQUIRED RADIUS OF 90 BENDS (SOURCE: ARC (2007)) .................................................................. - 12 -FIGURE 5. RIVER PUMPS SUCTION AND DELIVERY SIDE FITTINGS ..................................................................... - 13 -FIGURE 6. BOOSTER PUMP STATION 250MM 90° SUCTION BEND .................................................................... - 14 -FIGURE 7. CONCENTRIC AND ECCENTRIC REDUCERS ......................................................................................... - 14 -FIGURE 8. CORRECT INSTALLATION OF ECCENTRIC REDUCERS ON BOOSTER PUMPS ...................................... - 15 -FIGURE 9. SPACING AND PLACING OF SUCTION PIPE INLETS............................................................................. - 16 -FIGURE 10. RIVER PUMP STATION’S SUCTION INLETS IN THE KOMATI RIVER ................................................... - 16 -FIGURE 11. MINIMUM WATER DEPTH ABOVE SUCTION PIPE INLET ................................................................. - 17 -FIGURE 12. ATMOSPHERIC PRESSURE VS. HEIGHT ABOVE SEA LEVEL ............................................................... - 18 -FIGURE 13. RECOMMENDED INSTALLATION HEIGHT ........................................................................................ - 19 -FIGURE 14. TRANSFORMER AND REMAINS OF THE STOLEN MAIN SUPPLY CABLES .......................................... - 29 -FIGURE 15. FULLY EQUIPPED BLOCK HYDRANT HYDRAULIC VALVE .................................................................. - 30 -FIGURE 16. MEASURING APPARATUS FOR SPRINKLER NOZZLE SIZE ................................................................. - 31 -FIGURE 17. TONNES CANE PER HECTARES ......................................................................................................... - 34 -FIGURE 18. ANNUAL ELECTRICITY COSTS ........................................................................................................... - 35 -FIGURE 19. AMOUNT SPENT ON PUMPS MAINTENANCE AND/OR REPAIR ....................................................... - 40 -Asihlumisane Farmers Association Report - 2009Page vii

LIST OF APPENDICESAppendix 1: SEB usage for river pump stationAppendix 2: Capital recovery factors (CRF)Appendix 3: Soil map and block layoutAsihlumisane Farmers Association Report - 2009Page viii

ABBREVIATIONSAbbreviationAEARCASAECUCVDUEACEUFAGARHDPEMCCNARNPSHPVCRSSCSABISESSASWADEUsDescriptionApplication EfficiencyAgricultural Research CouncilAmerican Society of Agricultural EngineersChristiansen’s uniformity coefficientCoefficient of VariationDistribution Uniformity coefficientEquivalent Annual CostEmitter UniformityFarmers AssociationGross Application RateHigh Density PolyethyleneMotor Control CentreNet Application RateNet Positive Suction HeadPolyvinyl ChlorideRoyal Swaziland Sugar CorporationSouth African Irrigation InstituteSystem EfficiencySwaziland Sugar AssociationSwaziland Water & Agricultural Development EnterpriseStatistical UniformityAsihlumisane Farmers Association Report - 2009Page ix

1 I N T R O D U C T I O NAssociation general information1. Farm name: Bhalekane Prison Farm2. Name of Association: Asihlumisane Farmers Association3. Location:Area:MadlangempisiLatitude -2 882 954.604Longitude 57 594.778Altitude 315Maximum Temperature 40Minimum Temperature 84. Postal address: 1107 Matsapha5. Contact Details:Chairman – Mr. C. Mkwanazi 605 0544Farm Supervisor – Mr. Ngozo 624 40106. Area of farm (ha) 2117. Crops irrigated: Sugarcane8. Designers name and details: No.1 Irrigation and Maxflow9. Date of evaluation: 13 August 200910. Evaluators: Tiekie de Beer and Bongani BhembeAsihlumisane Farmers Association Report - 2009 Page - 1 -

2 B A C K G R O U N D O N I R R I G A T I O ND E V E L O P M E N TAsihlumisane is a savings and credit cooperative society exclusively for prison police officers(prison warders). Asihlumisane was founded in 1999 by the then commissioner of police Mr.E. Hillary. Water rights, sucrose quota and a 25 years lease agreement from the Governmentwere ratified in 2002 and phase one was implemented. The first phase of 108ha wasdesigned and installed by No. 1 Irrigation and the second phase is currently underconstruction and was designed by Dlamini Stewart Scott, an authorised representative ofSWADE.The project‣ Phase one of 108 hectares was executed under a design, supply, install and commissioncontract by No. 1 irrigation in 2002.‣ Phase two of 103 hectares is currently under construction and is implemented byMaxflow. This phase was designed by DSS Consulting Engineers.‣ The river pump station consists of an intake sump with a leading open channel into thesump, offset at an angle from the river. The sump was sized to accommodate 9 pumps.Three positions are being utilised. Four more pumps will be installed in phase two‣ Three KSB KRSv Cantilever Dewatering Pumps are installed at the river pump station forPhase One. The pumps are installed vertically mounted on the concrete walls of the sumpand extract water from the Komati River. These pumps are driven by 11kW 4-Pole electricmotors.Figure 1. River pump station along the Komati RiverAsihlumisane Farmers Association Report - 2009 Page - 2 -

‣ Flow between the concrete reservoir and the river pump is controlled by a float valvewhich trips the river pump when the reservoir reaches full capacity. This device is out oforder.‣ A flow meter is installed on the bulk water mainline inside a chamber.‣ The booster pump station is located next to the concrete reservoir and houses four KSBETA 125-50/2 pumps each powered by 4-pole 75kW motors. These pumping units areconnected in pairs to the two phases and can be interchangeable used.Figure 2. Booster pumps‣ Only Phase two pumps delivery pipelines are equipped with Bermad 700 series pressurerelieve valves.‣ The Motor Control Centres (MCC) of all pumps is well constructed.‣ Asihlumisane FA sugarcane varieties are N23 and N19.Asihlumisane Farmers Association Report - 2009 Page - 3 -

3 T E C H N I C A L A U D I T R E P O RT3 . 1 R E V I E W O F T H E I R R I G A T I O N D E S I G N C R I T E R I AA N D S P E C I F I C A T I O N S3.1.1 I r r i g a t i o n D e s i g n C r i t e r i a a n d S p e c i f i c a t i o n s b yc o n s u l t i n g e n g i n e e rThe original design criteria for the irrigation systems as given by the consulting engineer(Stewart Scott) to all contractors during tendering are given below.3.1.1.1 General Description of phase one ContractThis contract comprised of:A. The design, supply and commission of a river pump station, tracks, intake, electricaltelemetry and mechanical equipment, meter and installation and commissioning.B. Design, supply, and construction of pumping main, including layout, details and material.C. Design, supply, and construction of reservoir, including inlet, outlet, scouring, overflowsand screening facilities and telemetry.D. Design, supply, installation and commissioning of a booster pump house, electrical &mechanical equipment & telemetryE. Design, Supply, Install and commission 211Ha irrigation system for Phase 1 and 2.No. 1 irrigation was responsible for the complete design, supply, delivery, installation,excavation and backfilling, testing, commissioning, preparation of Operation and maintenancemanuals, training of operating personnel for Mechanical and electrical equipment,associated civil works and all irrigation piping for the initial 108 Ha.3.1.1.2 Phase two Irrigation Design CriteriaThe main criterion for the design of the irrigation system for Phase One was not supplied. Themain criteria for the design of the irrigation system given to the contractor for Phase 2 are asshown below:Crop…………………………………………………Sugar caneIrrigation cycle………………………………………12daysNet Application………………………………………39mmAsihlumisane Farmers Association Report - 2009 Page - 4 -

Application efficiency…………………….…………75%Gross application……………………………………26mmStand time………………………………….…………12HoursGross precipitation…………………………………….4.33mm/ hourSprinkler spacing………………………………………18m x 18mAnnual irrigation Hours…………………………………3300 hours3.1.1.3 System Pumping StationThe existing river pump station consists of an intake sump with a leading open channel intothe sump, offset at an angle from the river. The sump was sized to accommodate 9 pumps.Currently, 3 pump positions are being utilised. There is also a settling tank, pump station anddelivery mains.The sump is a rectangular structure with a narrow section that permits only vertically mountedpumps to be installed as attached drawings show. The suction head is variable depending onselected pump positions and water level in the river. The sump has no access ladder, andprotective rails.3.1.1.4 River Pump SetsThe existing pumps are KSB KRSv Cantilever Dewatering Pumps, driven by 37 kW 4-poleTEFC electric motors. The motors are directly coupled and vertically placed above thepumps. These units supply 108 l/sec in total. There are no pressure gauges installed on thedelivery manifold. The pumps are installed vertically mounted on the concrete walls of thesump.An 18m diameter reservoir, 2m height is located between at booster pump station3.1.1.5 Irrigation Pump SetsThe booster pump station has two KSB ETA 125-50/2 end suction pumps, driven by 75 kW 4-pole TEFC electric motors. The pumps and motors are mounted on base plates which arebolted on to the concrete floor slab of the booster pump house.3.1.1.6 Irrigation SystemThe development is a semi-permanent overhead sprinkler system. A Bermad 300 seriespressure reducing valve controls each individual irrigation block. Laterals are 32mm HDPEAsihlumisane Farmers Association Report - 2009 Page - 5 -

Class 6 Econothene pipe and compression type fittings. Aluminium hydromatic withgalvanised standpipe connect the hydromatic to the saddle of the lateral. Rainbird brasssprinkler with 11/64” nozzle is mounted on 3m sugar tripod. Laterals are installed 600mmunder the surface while the submains are 1m with a 50mm flush valve at the end.PVC AND HDPE PIPEAll PVC pipe supplied are Class 6 or Class 9 mPVC to SABS 966 Part1 or 2 specifications.Fittings comprise of Boseng PVC fittings or cast iron with Z joints. All HDPE pipe supplied areClass6 or Class 10 Type 4 to SABS 533 Part 2 specification. Fittings comprise of Plassoncompression and saddle fittings..SURFACE DRAINAGEThe Farmers Association is responsible for surface drainage to prevent erosion damage tothe fields and the system.3.1.1.7 Mainline, sub-mains and irrigation system layout3.1.1.7.1 Mainline and sub-mainsDepth:1.2 metersMaterial:PVCMaximum Diameter: 350 mm UPVC Class 9Flushing Valve:50 mm ball valve (at the end of eachsubmain) VaSA or similar3.1.1.7.2 HydrantsPressure testing valve:Shraeder Valve (SIV)Point Tester:50 mm Pressure testinggauge with (SN) connection.Height above ground:0.3 metersValve:Gulf, Bermad, Gal, Saunders or KimStand Pipe: Galvanized or HDPE Class 103.1.1.7.3 LateralsDepth:0,6m for Dragline FieldsDepth:0,6m for Semi Solid set FieldsPipe:HDPE for diameter less than 50mm andPVC for diameter greater than 5mmHDPE Pipe:SABS or Econothene HDS AS4130Flushing Valve:Required for a group of lateralsAsihlumisane Farmers Association Report - 2009 Page - 6 -

Dragline hose: 20mm Conflex 7793.1.1.7.4 Pump control valve in booster pump stationBermad valve – double chamberPressure sustaining and pressure reducingLimit switchSolenoid controlled on/off3.1.1.8 Review of Contractor Irrigation Design Criteria and Specifications3.1.1.8.1 PlanningOf the four major input of planning namely crop, climate, soil and irrigation system, the studyrevealed that crop and climate information used as supplied by the SSA (Swaziland SugarAssociation). Attached in appendices is a soil map of Asihlumisane Farmers Associationindicating major soil types the project was developed on.The purpose of this study was, therefore, to determine the quantity of water required by thecrops per cycle during peak demand periods and how often it was to be applied takingpractical operating practice into account.Taking soils into account the following planning schedule was developed;Peak Design-Norm For Sprinkler Irrigation At Asihlumisana Farmers Ass.1 GENERAL INFORMATION1,1 Owner Asihlumisana Farmers Association1,2 Farm Name - Number - Co-ordinates Swazi nation land1,3 Telephone number1,4 Area developed 86 Ha1,5 Water Allocation 86 l/s2 CLIMATE2,1 Month state Jan2,2 Weather station state Mhlume2,3 Evaporation mm/day 7mm A-Pan or 5mm Grass Factor3 MANAGEMENT3,1 Available working days per week days 73,2 Available working Hours per day hours 244 CROP BLOCK NO Lesibovu/Shortlands Betusile/Oakleaf4,1 Type state Sugar SugarAsihlumisane Farmers Association Report - 2009 Page - 7 -

4,2 Area Ha 20 94,3 Plant spacing m NA NA4,4 Row spacing m 1.8 1.84,5 Effective root depth m 0.45 0.454,6 Plant time date August August5 SOIL Lesibovu/Shortlands Betusile/Oakleaf5,1 Effective soil depth m 1 15,2 Water holding capacity mm/m 180 1405,3 Easy available water (10-50 kPa) 50% mm/m 90 405,4 Easy available water in root zone mm 40.5 186 WATER6,1 C en S Classification of water C+S Komati River7 EMITTER7,1 Type type Vyrsa 70 Vyrsa 707,2 Nozzle size mm 11/64 11/647,3 Discharge l/h 1390 13907,4 Working pressure kPa 350 3507,5 Application efficiency % 70 707,6 Emitter spacing m 18 187,7 Lateral spacing m 18 187,8 Wetted diameter m 36 367,9 Gross Application rate on wetted area mm/h 4.29 4.297,10 Nett Application rate on wetted area mm/h 3.33 3.338 SCHEDULING8,1 Crop factor (max) max 1.15 1.158,2 Evaporation mm/day 5 58,3 Evapotranspiration mm/day 5.75 5.758,4 Net Irrigation requirement mm/day 5.75 5.758,5 Gross Irrigation requirements mm/day 6.04 6.048,6 Theoretical cycle length day 7.04 3.138,7 Theoretical Stand time hour 12.16 5.408,8 Practical Cycle length day 6 38,9 Practical Stand time hours 12 68,10 Working days per week days 7 78,11 Irrigation hours per day hours 24 248,12Gross application rate per practicalcycle mm 51.48 25.748,13 Gross application per month mm 220.62 257.409 SCHEDULE OF BLOCKS THAT IRRIGATE TOGETHERAsihlumisane Farmers Association Report - 2009 Page - 8 -

10 HYDRAULICS10,1 Pressure difference over block m 40 4010,2Pressure at beginning of sub main orlateral m 40 4010,3 Velocity in mainline (max) m/s 1 111PRACTICAL STAND TIME / START TIMEfor 6 Day Cycle length11,1 Position 111,2 Position 211,3 Position 311,4 Position 411,5 Position 511,6 Position 611,7 Position 711,8 Position 811,9 Position 911,10 Position 1011,11 Position 1111,12 Position 1211,13 Position 1 start at beginning againStart EndDay 106,00 Day 1 18,00Day 118,00 Day 2 06,00Day 206,00 Day 2 18,00Day 218,00 Day 3 06,00Day 3Day 306,0018,00Day 3Day 418,0006,00Day 406,00 Day 4 18,00Day418,00 Day 5 06,00Day 506,00 Day 5 18,00Day 518,00 Day 6 06,00Day 6 Day0606,0018,00Day 6Day 718,0006,00Day 806,0012 FILTER12,1 Type State12,2 Total total12,3 Filtration size micron12,4 Pressure loss over filter (clean) m12,5 Pressure lose over filter (dirty) m13 DESIGNER13,1 Name Tiekie de Beer13,2 Company Tiekie de Beer Consulting13,3 SABI Membership Designer FellowAsihlumisane Farmers Association Report - 2009 Page - 9 -

Climatic information:Climatic information used when compiling the above schedule was obtained from SAPWATand a summary of which is shown by the figures below.Figure 3. SAPWAT screen indicating water requirement for sprinkler irrigation with rainfalltaken into accountSoil informationSoil properties used when compiling the afore schedule was obtained from the below charts.These are the three major soils found within the farm, an outline of which is shown on a soilmap attached in annexes.Asihlumisane Farmers Association Report - 2009 Page - 10 -

4 F I E L D E V A L U A T I O N O F I R R I G A T I O NS Y S T E M4 . 1 P u m p s a n d P u m p S t a t i o n s4.1.1 P u m p S u c t i o n S i d eThe majority of problems occurring with pumps are usually the result of poor suction sidedesign and installation. The installation and design of the suction side must ensure thatturbulence occurring and collection of air in high places in the suction pipe, is prevented. Inview of the above, the different suction side components were evaluated.4.1.1.1 Suction Pipe Flow RateThe suction pipe flow velocity of river and booster pumps was calculated as follows:353,68 QV m / s2d ………………………………….… (1)Where: V = flow velocity in pipe (m/s)Q = flow rate (m³/h)d = inner diameter of suction pipe (mm).RIVER PUMP STATIONThe river pump station consists of 3 KSB KRSv 100-250 Cantilever Dewatering Pumps,driven by 11kW 4-Pole TEFC electric motors. According to the design criteria provided byDSS these units supply 108l/s (388.8m³/hr) in total, each pump therefore must generate atleast 36l/s (129.6m³/hr) flow. Four additional pumps, of the same make and model will beinstalled with phase two installation currently under construction. Flow meter recordsindicated that these pumps, for the past 30 days were generating at most 76m³/hr flow.The suction piping should be firmly secured to the suction flange, preventing any air fromentering into the system. Generally these types of pumps are supplied with a suction strainersecured either directly to the suction flange or the suction spool. Asihlumisane pumps haveneither of the above and to ensure flow velocity of 1.5m/s and under the suction pipe must beat least 200mm.Asihlumisane Farmers Association Report - 2009 Page - 11 -

BOOSTER PUMP STATIONWater is pumped from the river pumps into a 425m 3 balancing reservoir from which two KSBETA 125-50/2 end suction booster pumps are installed. Two additional identical pumps will beinstalled upon completion of phase two. The ultimate flow, calculated from river pumps ofboth phases is 907.2m³/hr (252l/s). A 500mm suction manifold is installed from the reservoirsupplying water into the intake manifold of these pumps and the suction flow velocity throughthis manifold is 1.3m/s.In total, four booster pumps will be installed and each will generate an ultimate flow of226.8m³/hr (63l/s). These pumps are connected to the 500mm main suction manifold through250mm steel pipelines and the suction flow velocity through these is 1.34m/s. According tothe Agricultural Research Council, ARC (2007) the ideal suction pipe flow velocity must be1.0 m/s, but suction pipe flow velocities up to 1.5 m/s are acceptable. Booster pumps suctionpipelines are therefore of the correct diameter.4.1.1.1.1 Requirements for Fittings90º BendsThe radius (mm) of a 90º bend must be, at least, as shown in Figure 4.rdFigure 4. Required radius of 90 bends (source: ARC (2007))r 2d100mm …………………………………... (2)Where: r = radius of bend (mm)d = inner diameter of suction pipe (mm).Asihlumisane Farmers Association Report - 2009 Page - 12 -

RIVER PUMP STATIONAll 90° bends measured from the three pumps have shorter radiuses than required. 100mm90° bends are connected to the delivery pipes of the individual pumps have a radius of150mm. According to figure 4 and equation 2 above the required minimum radius is 300mm.However, there is more than five time the suction and delivery pipe size diameter pipe furtheron from these bends; the effects of the incorrect sizes are insignificant.Figure 5. River pumps suction and delivery side fittingsBOOSTER PUMP STATIONA 250mm 90° bend is installed on the suction pipe of all booster pump and are 300mm inradius. According to figure 4 and equation 2, 250mm 90° bends should have a radius of atleast 600mm.Asihlumisane Farmers Association Report - 2009 Page - 13 -

Figure 6. Booster pump station 250mm 90° suction bendReducersThe inlet on the pump suction side must be eccentric with the straight side towards the top, toprevent air collecting in the suction pipe and causing cavitation (ARC, 2006). The lengths ofboth eccentric and concentric reducers were evaluated against equation 3 below, adoptedfrom the ARC (figure 7).Figure 7. Concentric and eccentric reducers ( d )………………………... (3)52d1Where: = length of the reducer (mm)d1 = smaller inner diameter (mm)d2 = larger inner diameter (mm)Asihlumisane Farmers Association Report - 2009 Page - 14 -

The submersible dewatering river pumps have neither eccentric reducers nor concentricreducers. Concentric and eccentric reducers were installed as per recommendations on allbooster pumps. Eccentric reducers were installed with the straight side towards the top, toprevent air collecting in the pipe and causing cavitation. The length of the 150-250 eccentricreducers attached to all booster pumps 700mm and according to equation 3 above theseshould be at least 500mm. these are correctly dimensioned.150-125 concentric reducers are installed on the delivery side of all booster pumps and are140mm long. According to equation 3 this reducers should be 125mm. Again these arecorrectly dimensioned.Figure 8. Correct installation of eccentric reducers on booster pumps4.1.1.1.2 Suction Pipe InletsRIVER PUMP STATIONSpacing and placing of suction pipe inletsIn a well constructed sump the inlet of the suction pipe must be in accordance to therequirements of at least 0,5d (d = inner diameter of the suction pipe) from the bottom of thepump sump (figure 9) and at least 1,5d away from the side of the pump sump.Asihlumisane Farmers Association Report - 2009 Page - 15 -

d1.5d0.5dd3d 3d 1.5dFigure 9. Spacing and placing of suction pipe inletsThe river pump station consists of an intake sump with a leading open channel into the sump,offset at an angle from the river. The sump was sized to accommodate 9 pumps. Currently, 3pump positions are being utilised. The sump is a rectangular structure with a narrow sectionthat permits only vertically mounted pumps to be installed as attached drawings show. Theinstallation of these pumps was within the above requirements except for one pump whichwas lowered and is at the bottom of the sump. The rest of the pumps are at least 700mmfrom the sump base.Figure 10. River pump station’s suction inlets in the Komati RiverThe water depth above the river pumps was measure to be 300mm and the acceptedminimum water depth above the suction pipe inlet is determined based on the individualsuction manifold flow velocity. According to the graph below at 1.5m/s recommended suctionAsihlumisane Farmers Association Report - 2009 Page - 16 -

flow velocity the minimum water depth should be approximately 0.9m. With such aninstallation air enters into the pumping system thus significantly reducing pump efficiency andperformance.Figure 11. Minimum water depth above suction pipe inletBooster pumps are installed at a lower level than the minimum water level in the reservoirs,which ensured that there is always water in the pump casing and suction pipe. This is themost preferred pump design criteria and installation was in accordance to the standards.4.1.1.1.3 Suction side lossesDuring the evaluation of the pump station, attention was also given to the length of thesuction pipe and fittings that were used. Friction losses for pipes were calculated as for anyother pipe (using Hazen-Williams equation) and secondary losses for fittings were calculatedwith the aid of the following formula:hf6375kQ4d2………………………………….. (4)Where: hf = secondary friction loss in fitting (m)k = friction loss factorQ = flow rate in the fitting (m³/h)d = inner diameter of the fitting (mm).Asihlumisane Farmers Association Report - 2009 Page - 17 -

A summation of friction loss across each booster pump’s foot valve / suction strainer, the 90°bend, eccentric reducer and the suction pipe gave a total hf of 1.17 meters. River pumps donot have suction piping hence no suction side losses. Friction in the suction pipe has a directeffect of maximum suction height and consequently the available net positive suction head(NPSH) and is discussed below.4.1.1.1.4 Suction heightThe essence of this evaluation was to determine the actual static suction head of the installedpumps and then compare it to the designers suction height assumption. The maximumsuction height was calculated using equation 5 below;hs(max) hdhfhvp NPSHrequired ………………. (5)Where: hs (max) = maximum suction height (m)hd = atmospheric pressure on terrain (m) – figure 15hf = suction side losses (friction losses and secondary losses in fittings, m)hvp = vapour pressure of water (m)NPSH required = net positive suction head from the pump curve (m).Figure 12. Atmospheric pressure vs. height above sea levelAsihlumisane Farmers Association Report - 2009 Page - 18 -

River Pump StationThis pump has the capability of operating effectively at different suction heights but accordingto the manufacturer this pump must be installed as shown by the figure 13 below.Figure 13. Recommended installation heightThis pumping unit is mounted on the wall of the sump and 700mm from the base of the sump.This ensures that there is always water in the pump casing and suction pipe, a conditionreferred to as positive suction head. The installation of this pumping unit is within the ARCrecommendation of NPSHrequired < NPSHavailable. This confirms that the pump is installedat the correct height above sea level and with all factors equal pumps should functionproperly.BOOSTER PUMP STATIONThese pumps are installed at a lower level than the minimum water level in the reservoirs,which ensured that there is always water in the pump casing and suction pipe. This is themost preferred pump design criteria and installation was in accordance to the standards.NPSH required (from manufacture) was available (calculated using equation 5) and again thiswas within the requirements of NPSHr

table 1 below indicates Asihlumisane Farmers Association irrigation pumps and motorsspecifications as observed from the information plate of the respective units.Table 1. pump and motor specifications and measurements conducted on all pumpsPUMP SPECIFICATIONS FROM INFORMATION PLATE AND MEASUREMENTSRiver Pump Station Booster Pump StationMake / model KRS-v 100-250 ETA 125-50/2Number of units 3 + 4 (Phase 2) 2 + 2 (Phase 2)Pump duty point 36l/s @ 11m 63l/s @ 80mImpeller diameter mm STD F/S (405)Pressure under normal operation m - -MOTOR SPECIFICATIONS FROM INFORMATION PLATE AND MEASUREMENTSModel and type CMG AlstomPower (P motor) kW 11 75Power factor (cos ø) 0.85 0.87Motor efficiency (µ) 89.2 93Speed rpm 1460 14754.1.1.2.1 Pump OperationRiver Pump Station:All pumps were not in operation because supply cables from the transformer to the boosterpump station were stolen. Only two pumps were running before this incident. The third pumpwas removed for repairs more than two months back. Flow meter records of the two riverpumps revealed that these pumps were operating below capacity. For the past 30 days thesewere generating at most 76m³/hr flow instead of the required 259.2 m³/hr.Booster Pump Station:The performance of booster pumps could not be completely evaluated not only becauseelectrical cables from the transformer to the MCC were stolen but because its dischargecould not be determined due to a lack of flow measuring devices. Records revealed thatthese pumps generate around 850kPa pressure but when the two pumps are runconcurrently the second pump trips. Therefore, the conclusion as to whether these pumpsperform as indicated on attached pump curve or not could not be drawn.4.1.1.2.2 Power required on the pump shaftAsihlumisane Farmers Association Report - 2009 Page - 20 -

The power required on the pump shaft was calculated as soon as the total pump head anddelivery was calculated. The pump duty points of both the river and booster pumps are shownin table 1 above and the power required on the pump shaft was calculated with the followingformula and establishes whether motors were sized accurately.P g H Q36,000………………………………………. (6)Where: P = power required on the pump shaft (kW)ρ = density of water (1000 kg/m³)g = gravity acceleration (9.81 m²/s)H = pump pressure at service point (m)Q = pump delivery at service point (m³/h)η = pump efficiency at service point (%)Based on the design duty point, as shown in table 1 above the required power on the pumpshaft of river and booster pumps is a theoretical value of 10.3kW and 62.5kW respectively.The power output of the motor must be 10-15% greater than the power required on the pumpshaft giving a value of 11.89kW and 71.88kW for river and booster pumps respectively (ARC,2007). The three river pumps that are currently installed are powered by 11kW 4-Pole motor.According to the above calculation a 15kW motor was to be installed, but because the pumphead is estimated the 11kW motor can be used especially at low pump pressure. Boosterpumps on the other hand are driven by 75kW motors which are of the correct size.The required power, Prequired , of these pumps must be compared with the output power of theelectric motor obtained from measurements of voltage and current. As mentioned earlierneither river nor booster pumps were in operation during the audit.4.1.1.2.3 Pump Station General EvaluationRiver Pump Station‣ The river intake sump is not protected from storm water and/or flooding. Sand and debriscarried with runoff water are deposited into the sump. Otherwise this structure wasAsihlumisane Farmers Association Report - 2009 Page - 21 -

acceptable constructed offset at an angle from the Komati River. Sand intake from theriver is into the sump is minimal.‣ Recently Maguga dam was full and when water was released from the dam the riverpump station was flooded submerging even the motors. The farmers were not informedbeforehand so as to retract the pump, even if they were informed the water level duringthis period was above the support beams. A lot of money was lost as a result.‣ These pumps are vertically mounted and direct coupled to their individual motors. Thepump and motor shafts are, unfortunately inaccurately aligned. This misalignment resultsin excessive vibration and wears on the rotating component. In fact one of the threepump’s shaft was cut into half and the pump that is out for repairs will be cut as well.‣ The sump was designed for 9 pumps and only 3 were installed during the evaluation.‣ There are no pressure gauges on all river pumps.‣ The sump has no access ladder and protective rails‣ The strainer on the sump intake is not properly anchored on the sump walls and is wornout. Debris is able to pass through into the pumps.‣ Flow control and flood warning system must be incorporated into this design.‣ Starting and stopping of the river pump is controlled by an electric float valve inside theconcrete reservoir. This unit is currently out of order.‣ All river pumps do not have emergency stop buttons. The MCC for these are locatedinside the booster pump house 70m away.‣ These pumps generate a lot of noise during operation and noise reduction strategieshave to be implemented.‣ All phase one fittings are corroded. Galvanized fittings must be installed insteadBooster Pump Station‣ The booster pump station, storage reservoir and the river pump station are wellconstructed with good aesthetic value.‣ This pump station has well constructed MCCs, good security measures, ample workingspace and a well constructed lighting and ventilation system.‣ The booster pump station was designed for at least four pumps, two installed with theconstruction of phase one and two more have just been installed wih phase twoinstallation.‣ Only Phase two pumps delivery pipelines are equipped with Bermad 700 series pressurerelieve and pressure sustaining valves.Asihlumisane Farmers Association Report - 2009 Page - 22 -

Pumps alignmentRiver pumpsRiver pumps are vertically mounted and direct coupled to their individual motors. The pumpand motor shafts are inaccurately aligned. This misalignment results in excessive vibrationand wears on the rotating component.Booster pumpsThe alignment of the booster pumps and the motors was also evaluated. This was done byplacing the edge of a straight steel ruler over the coupling flanges at four points, 90º apart.This straight edge rested equally on all points on the flanges to ensure parallel alignment.The distance between the coupling levels at 90º intervals was also measured. A Verniercalliper was used. Measurements were the same on all the points and that meant the unit issquarely aligned.4.1.2 P o w e r S u p p l y A n d C o n s u m p t i o nPower consumptionA basic economic analysis was undertaken to ascertain the trade-off between capital andenergy costs. For this economic analysis the Equivalent Annual Cost method (EAC) wasused. The EAC adjusts the costs of items to a stream of equal amounts of payment overspecified periods (equivalent annual costs) in order to enable comparison.Items costed were:‣ Infield irrigation (tape and fittings including flusher lines and valves - considered aspolythene). Including installation costs.‣ Distribution system - pipelines (main lines and submains - considered as PVC).Including installation costs.‣ Pumping plant (including pump control valves, flow meters, electrical components,motors etc). Included installation costs. Where no new pumps were included, all andany supplementary equipment/operations connected with pumping e.g. upgrades,new impellors, new switchgear, new valves were included‣ Primary filter station (only filters and associated pipework, valves etc).Asihlumisane Farmers Association Report - 2009 Page - 23 -

Excluded were:‣ All existing infrastructure (e.g. AC pipe, balancing dam, MCC housing, etc)‣ Buildings (e.g. cluster houses, pump stations, filter station structure)‣ Valves external to pump stations and filter stations.‣ Irrigation controller systems‣ Fertigation systemsThe operational costs for the schemes are confined to energy costs and maintenance(excluded labour. Admin etc).Interest rate: 10%Useful life (this analysis)Infield irrigation (Tape etc):10 yearsPVC/Poly pipe:Filters:Pumping equipment and electricsMaintenanceInfield irrigation: 3%Distribution - pipelines: 2%Pumping plant: 1%Filters: 3%20 years15 years15 yearsCapital Recovery Rate (CRF)factors:Volume water applied per hectare:SEB tariff – Consumption:Maximum demand:Efficiency of pumping plantEAC COMPUTATION MATRIX(See attached table)9000mI\3/ha/annum0.22 E/kWh69.42 E/kVaCalculate at design duty pointAsihlumisane Farmers Association Report - 2009 Page - 24 -

ITEM COST ITEM Main Bid1 Infield irrigationCapital cost (E)Useful life (years) 10Annual maintenance (%) 3EAC of infield irrigation (E)2 Distribution systemCapital cost (E)Useful life (years) 20Annual maintenance (%) 2EAC of Distribution system (E)3 Pumping plantCapital cost (E)Useful life (years) 15Annual maintenance (%) 1EAC of Pumping plant (E)4 FiltersCapital cost (E) -Useful life (years) 15Annual maintenance (%) 3EAC of Filters (E) -5 Annual Energy Cost (E) 196181.00Total EAC (E)Energy cost as a % of total EACFor sprinkler irrigation a 40% EAC value is accepted. A higher and a lower figure indicatesover design and under design respectivelyAsihlumisane Farmers Association Report - 2009 Page - 25 -

4.1.3 S u p p l y S y s t e mThe evaluation of the supply system is discussed under the following headings;4.1.3.1 Mainline sizeSABI norm suggests that for raising main lines with a diameter of 200mm or smaller amaximum of 1.5m friction for each 100 m pipe length (1.5%) is allowed (ARC, 2003).Mainlines with pipe sizes greater than 200mm are evaluated by determining the mosteconomical pipe diameter; capital and annual cost for different pipe diameters werecompared and the following equation is used;dkQ0.37i …..……………………….……… (7)Where: di = inside diameter of pipe, mmK= constant derived from annual irrigation hoursQ= flow rate (m 3 /h)River Pump StationFor annual irrigation hours of 3300, adopted by the sugar industry, the most economical pipesize diameter for the bulk water pipeline was calculated for the design flow of 907.2m³/hr tobe 351.67mm. This corresponds to 400mm nominal PVC and/or 400mm diameter steel pipe.Design documentations and site investigations revealed that 12m x 250mm steel and 54m x200mm mPVC pipeline are installed from the river pump station to the reservoir. These areunder-designed. It is important to note, however that the flow used to calculate these pipesizes is for both phases.The pipeline under consideration was installed in phase one with only 388.8m³/hr flowrequirements. Under this consideration a 250mm steel and/or 315m PVC pipeline wassupposed to be installed. Based on the above calculations and observations it was concludedthat the bulk water mainline is under-designed.Booster Pump StationThe 150mm delivery pipes from the four pumps delivers into a 400mm steel main irrigationpipeline from which 315/9 mPVC pipelines are connected supplying the two phases. Basedon the design flow of 388.8m³/hr generated by phase one pumps, the most economicalAsihlumisane Farmers Association Report - 2009 Page - 26 -

nominal pipe size at 257.03mm inside diameter and this means that this section is correctlydesigned. Phase two is supplied through the same pipe size diameter and class.4.1.3.2 Mainline classFriction loss and required system pressure was used to determine pressure in variouspositions of the pipeline, according to which a suitable pipe class was determined. A hydraulicgradient (a line connecting the initial pressure to the end pressure) was drawn for the original(design) mainline. Static and dynamic conditions were studied to enable sensible and safepipe class selection. Irrigation mains start off as class nine and after approximately 13melevation head loss it changes to class six. The design pump pressure for booster pumps is80m and friction head loses in this 350m long pipeline is 2.3m leaving 64.7m availablepressure at the change-over position. This therefore, means a section 315/6 pipeline isunder-designed; the change-over from class 9 to 6 must be at 16m elevation head losses.4.1.4 S y s t e m c a p a c i t y e v a l u a t i o nThe following was noted;‣ irrigation requirement of the first phase were calculated based on the total irrigated area(108ha), industry norms of 2.57 sprinklers per hectare, 1.4m³/hr sprinkler discharge andwere approximately 388.58 m3/hr and 427.44m3/hr pump discharge (inclusive of 10%safety factor).‣ Phase two of 103 ha irrigation requirements were calculated just like above and areapproximately 307.6m3/hr and 407.65m3/hr pump discharge. This phase is still underconstruction.‣ Phase one was supplied by three identical river pump and four more will be installed uponcompletion of phase two. These pumps, in total will supply 907.2m3/hr compared to835.08m3/hr required pump discharges to meet irrigation requirements of both phases.This calculation, therefore indicates that six of these pump will generate this flow atapproximately 139.2m3/hr per pump and one will be a back-up pump.‣ The 139.2m3/hr is within the duty point of the installed KRSv 100-20-50 CantileverDewatering pumps at 13m maximum pump pressure, 1460 rpm pump speed and 13kWrequired power (refer to attached pump curve).‣ The design pressure of river pumps could not be ascertained and according but theheight from minimum river level to the water in the reservoir at full capacity was estimatedat 10m and allowing for 3m friction head losses across the bulk water pipeline pumpAsihlumisane Farmers Association Report - 2009 Page - 27 -

pressure must be around 13m. At this duty point the absorbed power increases to 12.9kWand this means that a 15kW motor should be installed.‣ The 11 kW motors currently installed in phase one pumps can generate a maximumpressure of 10m at 139.2m³/hr.‣ According to phase two designs, by DSS the four additional KRSv 100-250 will each bedriven by 37kW 4-Pole electric motors, directly coupled and vertically placed above thepumps. This size motor is too big and must not be installed as it will increase not only theimplementation costs but also the running costs of the scheme.‣ Four identical 75kW 4-pole motor driven ETA 125-50/2 pumps are installed andconnected to the two phases in pairs.‣ Phase one pumps must each generate at least 213.72 m³/hr flow. Phase two area issmaller than that of phase one hence smaller irrigation requirements. But in order for allfour pumps to be used interchangeable each of these must be able to generate thisoptimum flow.‣ Phase one design documents indicates a design pressure of 800kPa and phase twodesign document states that phase one design criteria and characteristics will be used forthe extension into phase two.‣ The duty point of all booster pumps should be 213.72 m³/hr pump discharge at 80m pumphead. This within the operating range of the installed pumps absorbing 59kW power at1460 rpm pump speed, 79% efficiency and 396mm impellor diameter.Asihlumisane Farmers Association Report - 2009 Page - 28 -

5 F I E L D E V A L U A T I O N O F S P R I N K L E R I R R I G A T I O NS Y S T E MTable 2. Sprinkler valuated block summaryArea (ha) 108Type of sprinkler system Semi-permanent Irrigation SystemName of DesignerNo. 1 IrrigationName of contractorNo. 1 IrrigationDesignmeasuredHydrant pressure (m) - -Sprinkler spacing (m x m) 18 18Lateral spacing (m) 18 17.5 -20Stand pipe height (m) 3 3Pressure regulator Yes NoDragline diameter (mm) 20 20Dragline length (m) 1 2 - 20A complete evaluation of the infields could not be carried out because the system was shutdown because electric cables supplying power to both pump stations from the transformerwere stolen.Figure 14. Transformer and remains of the stolen main supply cablesAsihlumisane Farmers Association Report - 2009 Page - 29 -

It is strongly recommended to conduct the distribution and delivery tests after harvesting todetermine defects, if any, in the design and installation of the infields. The followingobservations were made on the system;Hydraulic ValvesIn essence hydraulic valves maintain the design lateral/block pressure ensuring uniformpressure throughout the system. Block hydraulic valves are installed and equipped withpressure regulating pilots (figure 15). The installation of this unit (on the valve head) reducesa higher inlet pressure to a lower constant outlet pressure, regardless of fluctuating flow ratesand or varying inlet pressure. The pilot would sense down-stream pressure and modulatesopen or close, causing the main valve to throttle, thus maintaining constant delivery pressure.When down –stream pressure falls below the pilot setting, the pilot and main valve wouldmodulate open to increase pressure and maintain pilot setting. When downstream pressurerises above the pilot setting, the pilot and main valve would throttle close to decreasepressure and maintains pilot setting. The pilot has an adjusting screw to preset the desiredpressure.Figure 15. Fully equipped block hydrant hydraulic valveAsihlumisane Farmers Association Report - 2009 Page - 30 -

Nozzle wearingThe amount of sprinkler nozzle wear (mm) is on average 3 %, reaching a maximum of 4%.An increase of 5% in nozzle area means a 10% increase in flow and power demand, whichmeans additional operating costs and over-irrigation. The ARC therefore recommendssprinkler replacement if wear is greater than 5%. The amount of sand particles sucked bybooster pumps and pass through the nozzles is minimised because the river pump stationwas strategically positioned. Also, sand sucked by the river pumps is deposited in thereservoir. Scour valves to facilitate cleaning of the pipe work are well installed in all submains.Sprinkler nozzles were measured after the system was switched off with a specially machinedapparatus (Figure 16).Figure 16. Measuring apparatus for sprinkler nozzle sizeTechnical Properties of Sprinklers Found On Site:The effects of different nozzles/emitters and different sprinkler packages observed in thisproject were evaluated by identifying the response of the different emitters when subjected tothe same amount of pressure, all other factors equal. Table 3 below indicates the propertiesof the different sprinkler packages found on site when subjected to 35m sprinklerrecommended operating pressure.Asihlumisane Farmers Association Report - 2009 Page - 31 -

Table 3.Technical properties of sprinklers found on site at 35m operating pressureSprinkler Package Nozzle size Discharge (m3/hr Wetted Radius (m)Rain bird 30BH 5/32" nozzle 5/32” 1.14 14.8Rain bird 30BH 11/64" nozzle 11/64’’ 1.38 14.8Minimum Discharge (m 3 /hr) 1.14Maximum Discharge (m 3 /hr) 1.38Average Discharge (m 3 /hr) 1.26Flow variation (%) 19.05One sprinkler package with two different nozzle sizes were identified as shown in table 3above. Flow variation due to the different sprinkler – nozzle combinations is 19.05%, this ishigher than the ARC recommendation stating that the difference in discharge in a specificirrigation block may not vary by more than 10% from the average discharge. The averageapplication rate of the above combination is 1.26m³/hr and is below the design application of1.4m³/hr. This figure indicates that even on highly efficient pumping and supply system,irrigation efficiency will not improve, at least not until uniformity in this regard is obtained. Thisdifferent combination has an effect also on the wetting diameter due to their different bodytrajectory angles.Gross Application Rate (GAR)The gross application rate (GAR) of the sprinkler is thereafter calculated, by means of thefollowing formula;GAR qe1000A ....…………………………………. (8) mm/hWhere; GAR = Gross Application Rateqe = Sprinkler dischargeA = wetted area (m 2 )The GAR is a fraction of emitter discharge and sprinkler spacing as indicated by equation 8above. Emitter discharge of the identified sprinkler (table 3) at optimum performance wasused and their average discharge is 1.25m³/hr. with the 18m x 18m spacing the grossapplication rate is 3.9mm/hr. this is slightly lower than the design/recommended grossapplication rate of 4.2mm/hr. the evaluation of system capacity reflected that the design andAsihlumisane Farmers Association Report - 2009 Page - 32 -

the matching of the different components of the irrigation system are correctly implementedbut during the evaluation this system does not fully meet peak crop water requirements.Incorrect sprinkler nozzles were installed.5.1.1 S p r i n k l e r p r e s s u r eThe optimal operating pressure (kPa) of the sprinkler should be between 60 and 70 times thenozzle diameter (mm). This is applicable to nozzles of 3 to 7 mm diameter (ARC, 2006).Table 4.Technical properties of sprinklers found on site at 35m operating pressureSprinkler PackageRain bird 30BHRain bird 30BHNozzlediameterindicated11 / 64 "5 / 32 "NozzlediameterMeasuredRequired pressure according to normMinimum pressure Maximum pressurenozzle X 60 nozzle X 704.4 264 3084 234 273If the observed sprinklers are operated in accordance to these norms design sprinkleroperating pressure ranges between 234kPa to at most 308kPa. According to SABI norms,pressures in the block may not vary more than 20% from the average pressure. The aboveresults indicate a pressure variation of at least 27.3% and the average system operatingpressure of the entire system is below the recommended sprinkler operating pressure of350kPa.Asihlumisane Farmers Association Report - 2009 Page - 33 -

Average Tonnes Cane perHectare6 A S S E S S M E N T O F O P E R A T I O N , M A N A G E M E N TA N D M A I N T E N A N C E O F T H E I R R I G A T I O NS Y S T E M6 . 1 O p e r a t i o nFinancial viability for smallholder growerThe late conclusion of loan agreements (seasonal loans) results in the late delivery of inputsand late application of fertilizers and chemicals, which reduces yields and sucrose content,resulting in reduced financial returns per hectare and inability to recoup invested capital. Inaddition, the absence of any dividends for distribution to farming association members at theend of each season can lead to a decline in the cohesion of farmers’ associations/cooperatives,a cohesion which is essential to increasing on-farm efficiency.115.00110.00105.00100.00y = 1.892x + 93.4495.0090.0085.002003 2004 2005 2006 2007 2008Average TCH 89.64 96.37 107.61 100.06 111.22 95.48Figure 17. Tonnes Cane per HectaresThe first crop harvested in 2003 yielding 89.64 t/ha of sugarcane. The highest yield receivedby Asihlumisane is 111.22 t/ha and was in 2007. As indicated by the trend line productivity ofthis FA has been increasing over the years.Interest RatesIt can be argued that even relatively large reductions in interest rates have not had anysignificant impact on the sustainability of this sector. The sector appears to have deterioratedto one of a sustained financial crisis. This, therefore, calls for an integrated programme ofaction, to look at:‣ Discounted tariffs with regards to bank charges, including administration fees.Asihlumisane Farmers Association Report - 2009 Page - 34 -

Amount in Emalangeni‣ A re-look at the repayment period with regard to capital loans, with a view to having itextended from the current 7 years to at least 10 yearsConsidering the reduction of interest rates on all loans to a level not exceeding 12% perannum, such measures would allow smallholder growers to realize some return on theirinvestment and to be able to eventually pay dividends to the investing members. Alternativelyother financial arrangements can be put in place without any prejudice to the commercialoperations of the financial institutions currently engaged with the sector (SSA, 2008).ElectricityEnergy costs are too high. During dry periods the pumps run continuously for 24 hours perday and 7 days a week, there is a need to have the tariffs looked at and, maybe have thetariff rate discounted for sugar cane growers to enable them to be sustainable in thebusiness. It is imperative to train the farm manager and/or pump attendants on when and howmany pumps to start at a time as this affect electricity maximum demand.Figure 18 below indicates the actual amounts spent on electricity annually on both pumpstations since commissioning. This FA is, on average paying E25, 282.67 per month and has1.69kW energy requirements per hectare which is closer to the thumb-suck rule of 1.5kW perhectare. According to phase two design documentation energy requirements will increase to2.9kW per hectare. This is not acceptable. Also in view of the positioning of the two pumpstation, this irrigation project can be irrigated with only one pump station. Booster pumpshave enough capacity to pump from the river into the fields, by passing the storage reservoir.70,000.0060,000.0050,000.0040,000.0030,000.0020,000.0010,000.00Electricity BillAverage0.00Figure 18. Annual electricity costsAsihlumisane Farmers Association Report - 2009 Page - 35 -

Appendix three shows a calculation of the amount of energy used by this FA and compares itto what should have been used per season. This maximum demand calculation gives anindication of the amount small growers spend on electricity and how much could have beensaved when pumps are operated correctly.Production CostsSugar prices are on a continual downward spiral whereas production costs have taken theopposite direction, so that if no immediate plan of action is formulated to address theproblem, most smallholder growers will slowly but surely perish. Fertilizers, herbicides, farminputs, labour costs are making it difficult for the farmers to use the best farming practices.Maybe a solution to that could also be a consortium that can be formed for the sugarcanegrowing industry to have a muscle where buying of farm inputs is concerned (SSA, 2008).Transport costsSmallholder growers feel transporters have established a gold mine at the expense ofgrowers. A large chunk of sugarcane revenue goes to the transporters and growers feel thatthere is a need to address this issue and look at ways to improve the current situation. Thenon performance of transport operators leads to a heavy loss in cane quality which also leadsto a serious financial loss to the growers. The issue of mill distance from the farm is, in anumber of instances, of major concern. The mere construction of a bridge (s) across astream(s) would go a long way towards reducing these distances and, consequently, theattaching costs.MillersSmallholder cane growers feel that millers also have a significant role to play in assistingsmallholder growers technically, financially and otherwise. Bulk purchasing comes to mindhere as the millers are endowed with the financial muscle (economies of scale) which couldresult in discounted input prices for growers (SSA, 2008).6 . 2 M a n a g e m e n t P r a c t i c e sOperation and maintenance manual not availableThe different components forming the irrigation system require different operating proceduresand these are obtained from an operation and maintenance manual. This document is notavailable and for efficient performance of these components, it must be compiled. Theconsequence of not having this document is seen during this evaluation in that incorrectAsihlumisane Farmers Association Report - 2009 Page - 36 -

sequences are followed in opening and closing the pump. Also, this document helps in theformulation of a maintenance plan and provides guidelines to be followed duringmaintenance.Different Soil TypesThe different soil sets on which the project is developed have different water holdingproperties and require different irrigation patterns. However, only one irrigation pattern isimplemented by this FA. Irrigation stand time and irrigation cycle must be calculated based onindividual soil properties.SchedulingEffective scheduling ensures that the correct amount of water is applied at the right time andthe correct place. As a scheduling method Asihlumisane Farmers Association is using thegive and take method. This method utilizes long term evaporation means and rainfall isaccounted through rain gauge readings. There is no scheduling tool to accurately determinethe amount of water to be applied with every irrigation.Emitter discharge results of the identified sprinklers were used to calculate the amount ofwater applied to the crop. A 12 hour stand time starting at 0600hrs to 1800hrs is adopted witha 24hr working day. Two shifts are implemented daily and the following schematic is used forthis evaluationGiven:12 hours every 6 daysThus: 12 Standing time (hours)6 Cycle length (days)Already calculated: qe = 3.89 mmThus: hours x qe every 6 daysThus: 46.7 mm 6 daysGross mm per day = 7.8 mm/dayThus: Net mm per day = 5.85 mm/dayBased on this observation this system does not meet the 6.5mm/day recommendedsugarcane irrigation requirements. Management revealed that occasionally the cycle lengthincreases to two weeks especially when there is a problem with one of their pumps. This FAis thus under-irrigating.Asihlumisane Farmers Association Report - 2009 Page - 37 -

Training of farm manager and his assistantsSWADE, Swaziland Sugar Association and RSSC provide technical assistance to this FA.This evaluation revealed that particular attention has to be put into training this FA onoperation and maintenance of the irrigation system and ensure that equipment are replacedwith correct ones and by qualified technicians. Farmers do not have the required expertise onirrigation matters and end up making expensive mistakes. This FA is not in the position torectify mistakes hence they live with the results of an ineffective operation and managementregimes currently implemented. This capacity building exercise will go a long way intoimproving efficiency in this irrigation project.6 . 3 M a i n t e n a n c e S u r v e yWhen the impact of maintenance practices was evaluated, it was decided to classify theexisting maintenance practices followed by the producer, according to existing literaturesources as acceptable if it will not influence the performance of the system adversely andunacceptable/ineligible if it will impair the performance. The acceptable values are viewed asthe absolute minimum values for the sustaining of an acceptable Us value in the system.Table 5. Maintenance schedule for sprinkler irrigation systemsInspect the system for leakagesMonitor With each cycle AnnuallyCheck system pressure and system flowService air valves and hydrantsCheck sprinklers for wear and replace springs,washers and nozzles where necessaryXXXXFlush mainlinesXTable 6. Maintenance practices implemented by FAMonitor Results ClassificationInspect the system for leakages Daily AcceptableCheck system pressure and system flow Never UnacceptableService air valves and hydrants Attend to fault UnacceptableCheck sprinklers for wear and replace springs, washersand nozzles where necessaryNeverUnacceptableFlush mainlines Never UnacceptableAsihlumisane Farmers Association Report - 2009 Page - 38 -

6 . 4 H I S T O R Y O F S Y S T E M P E R F O R M A N C EFrom the compilation of table 7 below, the survey revealed that low yields experienced by thisassociation was not attributed only to the defective irrigation system and insufficient irrigationwater, but also to the fact that the occurrence of breakdowns is frequent. The downtime forthese breakdowns range from a week to one month and to date approximately E215 000.00has been spent on repair and maintenance of the system. About E168 000.00 of this amountwas spent only on pumps and the remainder on irrigation equipment (table 7).This high maintenance costs are attributed to various factors but mainly due to poorworkmanship by the engaged maintenance contractor. With the installation of phase two atleast one pump will be backup for both phases. The economic benefits of using only onepump station, i.e. pump from the river straight into the fields using the installed boosterpumps must be further evaluated. An alternative suction position will have to be identifiedwhere these pumps could efficiently operate.Table 7. pumps maintenance costs including major breakdown repair costsDate Details Amount9-Jul-03 Plumbing fitting done by No1. Irrigation 5,569.017-Jul-04 Plumbing maintenance done by No.1 Irrigation 2,043.8026-Nov-04 Pumps Maintenance done by Besproening 2,340.0018-Jan-05 Remove, repair, and replace river pump by HD Besproeing 8,845.0024-Feb-05 Repair river pumps by HD Besproeing 11,650.0010-Oct-05 Install new impellor and repair motor connect box 6,500.0010-Oct-05 Replace two booster pumps 6,500.0010-Oct-05 Electrical repairs done by HD Besproeing 4,590.0014-Dec-05 Pump maintenance on Pump No.1 and 2 8,634.0026-Apr-06 Service motor By Proton 3,450.0024-Jul-06 HRL coupling complete with element by Proton 1,260.0011-Oct-06 Pumps maintenance by Proton 12,085.0020-Nov-06 Pumps maintenance by Proton 4,979.4216-Jan-07 Plumbing fitting by Proton 672.1019-Feb-07 Plumbing pipes by Meduma investments 1,320.0024-Mar-07 Replace burnt motor on river pump by Proton 8,496.0024-Jul-07 Plumbing pipes by Meduma investments 819.6024-Sep-07 Supply, install and calibrate by Pro-Fluid 12,850.0024-Sep-07 Threading 12 pipes by Manzana Engineering 570.0027-Aug-07 Complete Pump set over-haul by Pro-Fluid 27,555.0027-Nov-07Supply and fit 1x6mx25mm UPVC, replace broken pipe byMeduma 4,104.00Asihlumisane Farmers Association Report - 2009 Page - 39 -

20-Jan-08 Maching a new shaft by Manzana Engineering 6,853.6025-Feb-08 Repairs to booster pump by Proton 4,920.1029-Apr-08 Repair river pumps by Proton 26,148.7730-May-08 Replacing new flow meter by Allen Mamba 1,800.007-Oct-08Trenching to remove and replace damaged pipe and backfilling by Meduma 2,064.5024-Nov-08 Repairs to river pumps by Proton 3,355.7021-Jan-09 Replacing new pipes by Meduma 18,304.0011-Mar-09 Installation of uPVC pipe by Meduma 8,905.007-Aug-09 Repairs to river pump drive motors by Industrilec 6,500.00TOTAL 213,684.60The graph below indicates only the amount spent on pumps maintenance and/or repairssince commissioning. Data in the above table is summarised below.60,000.0050,000.0040,000.0030,000.0020,000.0010,000.000.002004 2005 2006 2007 2008 2009Amount 2,340.00 46,719.00 21,774.42 48,901.00 41,278.17 6,500.00Figure 19. Amount spent on pumps maintenance and/or repairAsihlumisane Farmers Association Report - 2009 Page - 40 -

7 C O N S T R A I N T S T O E F F I C I E N T S Y S T E MP E R F O R M A N C EThe following constraints were identified to have an effect on productivity once the system isoperated.River pump station:‣ The river pump station consists of an intake sump with a leading open channel into thesump, offset at an angle from the river. The sump was sized to accommodate 9 pumps.Currently, 3 pump positions are being utilised.‣ According to the design criteria provided by DSS these units supply 108l/s (388.8m³/hr) intotal, each pump therefore must generate at least 36l/s (129.6m³/hr) flow. Four additionalpumps, of the same make and model will be installed with phase two installation currentlyunder construction. Flow meter records indicated that these pumps, for the past 30 dayswere generating at most 76m³/hr flow. These pumps are operating below the design flow.‣ Incorrectly sized fittings on the delivery manifolds affect system performance. The effectsof these are severe on the eccentric reducer because it is directly attached to the pumpand the sudden restriction in size increases turbulence occurrences and cause irregularfeeding of the pump hence cavitation. With such an installation wearing and maintenancecost of the pump will increase.‣ The water depth above the suction inlet was measure to be 300mm and the acceptedminimum water depth above the suction pipe inlet is determined based on the individualsuction manifold flow velocity. According to the suction flow velocity the recommendedminimum water depth is approximately 0.9m. Vortex forms when the pump is runningindicating that air is being sucked in with the water. This significantly reduces pumpefficiency.‣ Recently Maguga dam was full and when water was released from the dam the riverpumping units were submerged in the water. The farmers were not informed beforehandso as to retract the pump. A lot of money was lost as a result.‣ All pumps were not in operation because supply cables from the transformer to thebooster pump station were stolen. Only two pumps were running even before thisincident. The third pump was removed for repairs more than two months back.‣ The three river pumps that are currently installed are powered by 11kW 4-Pole motor.Power required calculations revealed that 15kW motors were supposed to be installed,but because the pump head is estimated the 11kW motor can be used especially at lowpump pressure.Asihlumisane Farmers Association Report - 2009 Page - 41 -

‣ According to phase two design documents four more river pumps are to be installed andeach driven by 37kW 4-Pole motors. These motors are over-sized and should beredesigned to match existing pumps.‣ Flow control and flood warning system must be incorporated into this design.‣ Starting and stopping of the river pump is controlled by an electric float valve inside theconcrete reservoir. This unit is currently out of order.‣ All river pumps do not have emergency stop buttons. The MCC for these are locatedinside the booster pump house 70m away.‣ These pumps generate a lot of noise during operation and noise reduction strategieshave to be implemented.Booster pump stations‣ The booster pump station is well designed and constructed with ample working space andventilation.‣ Water is pumped from the river pumps into a 425m 3 balancing reservoir from which fourKSB ETA 125-50/2 end suction booster pumps are installed. This pump is driven by a 4-Pole 75kW motor.‣ The concrete reservoir is leaking and reduced the conveyance efficiency of the irrigationsystem.‣ Incorrectly sized fittings in suction and delivery manifolds affect system performance. Theeffects of these are severe on the eccentric reducer because it is directly attached to thepump and the sudden restriction in size increases turbulence occurrences and causeirregular feeding of the pump hence cavitation. With such an installation wearing andmaintenance cost of the pump will increase.‣ The absence of flow measuring devices in this pump’s delivery manifold makes it difficultto measure and/or monitor pump performance.‣ Strainers inside the concrete reservoir are worn out.‣ Four identical 75kW 4-pole motor driven ETA 125-50/2 pumps are installed andconnected to the two phases in pairs. The duty point of all booster pumps should be213.72 m³/hr pump discharge at 80m pump head. This within the operating range of theinstalled pumps absorbing 59kW power at 1460 rpm pump speed, 79% efficiency and396mm impellor diameterAsihlumisane Farmers Association Report - 2009 Page - 42 -

MAIN LINE‣ The most economical pipe size diameter for the bulk water pipeline was calculated for thedesign flow of 907.2m³/hr to be 351.67mm. This corresponds to 400mm nominal pipesize. Design documentations and site investigations revealed that 12m x 250mm steeland 54m x 200mm mPVC pipeline are installed from the river pump station to thereservoir. These are under-designed. The pipeline under consideration was installed inphase one with only 388.8m³/hr flow requirements. Under this consideration a 250mmsteel and/or 315m PVC pipeline was supposed to be installed. Based on the abovecalculations and observations it was concluded that the bulk water mainline is underdesigned.‣ The 150mm delivery pipes from the four pumps delivers into a 400mm steel mainirrigation pipeline from which 315/9 mPVC pipelines are connected supplying the twophases. Based on the design flow of 388.8m³/hr generated by phase one pumps, themost economical nominal pipe size at 257.03mm inside diameter and this means that thissection is correctly designed‣ Identified sections of the sub-mains are slightly under-designed and some laterals areunacceptably long.‣ A section of the 315/6 pipeline is under-designed; the change-over from class 9 to 6 mustbe at the 16m contour.‣ Some sections of the mainline are leaking – overall system efficiency compromised.SPRINKLER INFIELD IRRIGATION‣ Block hydraulic valves are equipped with pressure regulating pilots. The installation of thisunit reduces a higher inlet pressure to a lower constant outlet pressure, regardless offluctuating flow rates and or varying inlet pressure.‣ Lateral and emitter spacing of this irrigation system is maintained between 17m - 20m.‣ The infields could not be completely evaluated because both pumps were not running.The system is shut down because electric cables from the transformer supplying bothpump stations were stolen.‣ The amount of sprinkler nozzle wear (mm) is on average 3 %, reaching a maximum of4%.‣ One sprinkler packages with two different nozzle sizes were identified and flow variationdue to the different sprinkler – nozzle combinations is 19.05%. This is higher than theSABI recommendation 10% flow variation.‣ The average sprinkler application rate is 1.26m³/hr and is below the design application of1.4m³/hr.Asihlumisane Farmers Association Report - 2009 Page - 43 -

‣ Gross application rate is 3.9mm/hr and is lower than the design/recommended grossapplication rate of 4.2mm/hr.‣ The evaluation of system capacity reflected that the design and the matching of thedifferent components of the irrigation system are correctly implemented but during theevaluation this system does not fully meet peak crop water requirements. Incorrectsprinkler nozzles were installed.‣ Sprinklers were not equipped with pressure regulators.‣ The first phase of the irrigation system was installed over 6 years ago, and as yearselapsed, the system efficiency reduces due to equipment wearing out. As a matter ofurgency some equipment must be replaced and the rest maintained for optimalperformance.‣ No drainage was planned with the development.OVERALL MANAGEMENT AND MAINTENANCEOperations‣ The late conclusion of loan agreements (seasonal loans) results in the late delivery ofinputs and late application of fertilizers and chemicals, which reduces yields and sucrosecontent, resulting in reduced financial returns per hectare and inability to recoup investedcapital‣ The first crop harvested in 2003 yielding 89.64 t/ha of sugarcane. The highest yieldreceived by Asihlumisane is 111.22 t/ha and was in 2007. As indicated by the trend lineproductivity of this FA has been increasing over the years.‣ It can be argued that even relatively large reductions in interest rates have not had anysignificant impact on the sustainability of this sector. The sector appears to havedeteriorated to one of a sustained financial crisis.‣ Electricity cost high: This FA is, on average paying E25, 282.67 per month and has1.69kW energy requirements per hectare which is closer to the thumb-suck rule of 1.5kWper hectare. According to phase two design documentation energy requirements willincrease to 2.9kW per hectare. This is not acceptable. Also in view of the positioning ofthe two pump station, this irrigation project can be irrigated with only one pump station.Booster pumps have enough capacity to pump from the river into the fields, by passingthe storage reservoir.‣ High Transport costs: A large chunk of sugarcane revenue goes to the transporters andgrowers feel that there is a need to address this issue and look at ways to improve thecurrent situation.Asihlumisane Farmers Association Report - 2009 Page - 44 -

‣ High Production Costs: Sugar prices are on a continual downward spiral whereasproduction costs have taken the opposite direction.Management and maintenance‣ The first crop harvested in 2003 yielding 89.64 t/ha of sugarcane. The highest yieldreceived by Asihlumisane is 111.22 t/ha and was in 2007. productivity of this FA has beenincreasing over the years‣ This FA is, on average paying E25, 282.67 per month and has 1.69kW energyrequirements per hectare which is closer to the thumb suck rule of 1.5kW per hectare.According to phase two design documentation energy requirements will increase to2.9kW per hectare. This is not acceptable. Also in view of the positioning of the two pumpstation, this irrigation project can be irrigated with only one pump station. Booster pumpshave enough capacity to pump from the river into the fields, by passing the storagereservoir.‣ Most equipment has been stolen and/or vandalised. This includes hydraulic valves,hydromatics, sprinkler stands, sprinkler and nozzles. These need to be replaced ormaintained.‣ Without an operation and maintenance manual, management have difficulty in operatingand maintaining the system. Incorrect operation procedures are followed and impropermaintenance schedules adopted.‣ No scheduling measurements were followed and under the current irrigation pattern theirrigation system cannot meet sugarcane irrigation requirement.‣ Based on the implemented irrigation pattern this system does not meet the 6.5mm/dayrecommended sugarcane irrigation requirements.‣ The different soil series on which the project is developed has different water holdingproperties and require different irrigation patterns. These are difficult to manage.‣ Farmers do not have the required expertise on irrigation matters and end up makingexpensive mistakes.‣ The downtime for these breakdowns range from a week to one month and to dateapproximately E215 000.00 has been spent on repair and maintenance of the system.About E168 000.00 of this amount was spent only on pumps and the remainder onirrigation equipment‣ This high maintenance costs are attributed to various factors but mainly due to poorworkmanship by the engaged maintenance contractorAsihlumisane Farmers Association Report - 2009 Page - 45 -

8 R E C O M M E N D A T I O N STo evaluate the constraints of the project properly we have decided to categorised therecommendations in four categories namelyA. Immediately: This has to been done direct after harvesting.B. Short term: This has to been done this seasonC. Medium term: This has to been done before replantD. Long term: This has to be rectified with replant.RIVER PUMPSImmediately:‣ Repair all faulty equipment ensuring that all river pumps running to full/design capacityE 30 000.00‣ Refurbish pump station i.e. construction of access ladder, rails, etc E 10 000.00‣ Establish arrangement with a reliable contractor to assist with the maintenance of allequipment.‣ The four 37kW 4-pole motors specified for phase two pumps must not be installed. theseare over-designedShort term:‣ Do routine maintenance on pumps and all equipment. E 20 000.00‣ Supply pumps with a suction strainer secured either directly to the suction flange or onthe suction spool. E 15 000.00‣ Replace all incorrectly dimensioned fittings (bends and reducers) on the delivery manifoldwith the correct size E 10 000.00‣ Improve pump and motor safety mechanisms E 20 000.00BOOSTER PUMPSImmediately:‣ Repair all faulty equipment ensuring that all river pumps running to full/design capacityE 30 000.00‣ Refurbish pump station and concrete reservoir E 25 000.00Asihlumisane Farmers Association Report - 2009 Page - 46 -

‣ Establish arrangement with a reputable establishment to assist with the maintenance ofall equipment.Medium term:‣ Replace all incorrectly dimensioned fittings on the suction and delivery manifold with thecorrect size E 15 000.00‣ Install flow and pressure measuring devices to monitor pump performance E 55 000.00Long term:‣ Change over to only one pump station. that is, pump from the river straight into the fields,using the already installed booster pumps E 200 000.00MAIN LINEImmediately:‣ Increase the size of the bulk water mainline E 75 000.00‣ Do routine maintenance on all equipment i.e. flow meter, air valves, mechanical valves,etc E25 000.00Medium term:‣ Correct all hydraulic errors in the irrigation mainlines and sub-mains, i.e. installing classnine pipes on identified mainline sections E 80 000.00‣ Install additional air valves E 7 500.00SEMI-PERMANENT INFIELD IRRIGATIONImmediately:‣ Fix all damaged/vandalised hydraulic valves at the beginning of semi-permanent blocks.E20 000.00‣ Fix all damaged sprinkler stands and replace leaking draglines and other malfunctioningequipment E10 000.00‣ Install uniform nozzle sizes of the acceptable discharge in all sprinklers E10 000.00Medium term:‣ Replant all block that perform badly E 50 000.00‣ Rehabilitate access/haulage roads E 120 000.00Asihlumisane Farmers Association Report - 2009 Page - 47 -

Long term:‣ Abandon soils with poor potential, and plant alternative crops‣ Install proper sub-surface drainageOVERALL MANAGEMENT AND MAINTENANCEOperations‣ Compilation of an operation and maintenance manual to assist in the implementation of aproper maintenance and operation strategies for the association.‣ Considering the reduction or termination of interest rates on all loans, such measureswould allow smallholder growers to realize some return on their investment and to be ableto eventually pay dividends to the investing members. Alternatively other financialarrangements can be put in place without any prejudice to the commercial operations ofthe financial institutions currently engaged with the sector.‣ There is a need to have the electricity tariffs looked at and, maybe have the tariff ratediscounted for sugar cane growers to enable them to be sustainable in the business.Pump attendance must be trained on economic ways of operating pumps.‣ A consortium could be formed for the sugarcane growing industry to have a muscle wherebuying of farm inputs is concerned. This could reduce production costsManagement‣ A proper scheduling tool must be adopted and, where possible, blocks scheduledaccording to soil type.‣ Establish arrangement with a reliable establishment to assist with the maintenance of allequipment.‣ Implement an irrigation pattern that will result into a 6.5mm/day net application.‣ Replace old equipment‣ Strengthen training of FA on operation and maintenance of irrigation systemAsihlumisane Farmers Association Report - 2009 Page - 48 -

9 C O N C L U S I O NAsihlumisane is a savings and credit cooperative society exclusively for prison police officers(prison warders). Asihlumisane was founded in 1999 by the then commissioner of police Mr.E. Hillary. Water rights, sucrose quota and a 25 years lease agreement from the Governmentwere ratified in 2002 and phase one was implemented. The first phase of 108ha wasdesigned and installed by No. 1 Irrigation and the second phase is currently underconstruction and was designed by Dlamini Stewart Scott, an authorised representative ofSWADE.River Pumps:The river pump station consists of an intake sump with a leading open channel into the sump,offset at an angle from the river. The sump was sized to accommodate 9 pumps. Currently, 3pump positions are being utilised. The sump is a rectangular structure with a narrow sectionthat permits only vertically mounted pumps to be installed as attached drawings show.The river pump station consists of 3 KSB KRSv 100-250 Cantilever Dewatering Pumps,driven by 11kW 4-Pole TEFC electric motors. According to the design criteria provided byDSS these units supply 108l/s (388.8m³/hr) in total, each pump therefore must generate atleast 36l/s (129.6m³/hr) flow. Four additional pumps, of the same make and model will beinstalled with phase two installation currently under construction.All pumps were not in operation because supply cables from the transformer to the boosterpump station were stolen. Only two pumps were running even before this incident. The thirdpump was removed for repairs more than two months back. Flow meter records of the tworiver pumps revealed that these pumps were operating below capacity. For the past 30 daysthese were generating at most 76m³/hr flow instead of the required 259.2 m³/hr.The three river pumps that are currently installed are powered by 11kW 4-Pole motor.Required power calculations revealed that 15kW motors were supposed to be installed, butbecause the pump head is estimated the 11kW motor can be used especially at low pumppressure. According to phase two design documents four more river pumps are to beinstalled and each driven by 37kW 4-Pole motors. These motors are over-sized and shouldbe redesigned to match existing pumps.Asihlumisane Farmers Association Report - 2009 Page - 49 -

Booster Pump Station:Water is pumped from the river pumps into a 425m 3 balancing reservoir from which two KSBETA 125-50/2 end suction booster pumps are installed. Two additional identical pumps will beinstalled upon completion of phase two. The ultimate flow, calculated from river pumps ofboth phases is 907.2m³/hr (252l/s). The duty point of each of these pumps should be 213.72m³/hr pump discharge at 80m pump head. This is within the operating range of the installedpumps absorbing 59kW power at 1460 rpm pump speed, 79% efficiency and 396mm impellordiameterMainlinesThe most economical pipe size diameter for the bulk water pipeline was calculated for thedesign flow of 907.2m³/hr to be 351.67mm. This corresponds to 400mm nominal pipe size.Design documentations and site investigations revealed that 12m x 250mm steel and 54m x200mm mPVC pipeline are installed from the river pump station to the reservoir. These areunder-designed. The pipeline under consideration was installed in phase one with only388.8m³/hr flow requirements. Under this consideration a 250mm steel and/or 315m PVCpipeline was supposed to be installed. Based on the above calculations and observations itwas concluded that the bulk water mainline is under-designed.The 150mm delivery pipes from the four pumps delivers into a 400mm steel main irrigationpipeline from which 315/9 mPVC pipelines are connected supplying the two phases. Basedon the design flow of 388.8m³/hr generated by phase one pumps, the most economicalnominal pipe size at 257.03mm inside diameter and this means that this section is correctlydesigned.Identified sections of the sub-mains are slightly under-designed and some laterals areunacceptably long. A section of the 315/6 irrigation main is under-designed; the change-overfrom class 9 to 6 must be at the 16m contour.Infield and Sprinkler EquipmentA complete evaluation of the infields could not be carried out because the system was shutdown because electric cables supplying power to both pump stations from the transformerwere stolen. It is strongly recommended, therefore to conduct the distribution and deliverytests after harvesting to determine defects, if any, in the design and installation of the infields.Asihlumisane Farmers Association Report - 2009 Page - 50 -

The following observations were made on the system; the first phase of this is irrigationsystem cannot meet GAR initially designed for and pressure and discharge variation aremore than the required 20 and 10% respectively, and there is a variation in nozzle sizes.Management:Irrigation scheduling is not practise and a proper irrigation scheduling tool will have to beintroduced to the industry, especially for small holder farmers association. Various schedulingtools are use in the industry and these include tensiomentry, neutron probes etcThis FA is, on average paying E25, 282.67 per month and has 1.69kW energy requirementsper hectare which is closer to the thumb-suck rule of 1.5kW per hectare. According to phasetwo design documentation energy requirements will increase to 2.9kW per hectare. This isnot acceptable. Also in view of the positioning of the two pump station, this irrigation projectcan be irrigated with only one pump station. Booster pumps have enough capacity to pumpfrom the river into the fields, by passing the storage reservoir.Performance of this irrigation scheme is affected, to some extent, by a lack or late applicationfor fertilisers, herbicides, high interest rates, high electricity cost, and the ever increasingproduction cost. Apart from these problems, operation, management and maintenance of thisscheme is complicated by the lack of a proper maintenance plan for pumps, lack of anoperation and maintenance manual, insufficient training on different components of system,old and worn-out equipment, and frequent breakages of pumps, laterals and draglines.Asihlumisane Farmers Association Report - 2009 Page - 51 -

10 L I T E R A T U R E R E F E R E N C E S1. ARC- Institute for Agricultural Engineering,1998. In-field Evaluations of thePerformance of two Types of Irrigation Emitters executed on behalf of the waterResearch Commission. Water Research Commission, Republic of South Africa.2. ASAE Standards. 1997. Field evaluation of micro-irrigation systems, ASAE EP458.3. ASAE Standards. 1998. Design and installation of micro-irrigation systems, ASAE EP405.14. Burt, C.M. & Styles S.W. 1994. Drip and micro-irrigation for Trees, Vines, and RowCrops. Irrigation Training and Research Centre (ITRC). USA.5. Keller, J, and Bliesner, RD. 1990. Set Sprinkler Uniformity and Efficiency Sprinkle andTrickle Irrigation. Chapman and Hall, New York.6. Koegelenberg, F. H. & others. 1996. Irrigation Design Manual. Agricultural ResearchCouncil - Institute for Agricultural Engineering. RSA.7. Koegelenberg, F. H. 2002. Norms for the design of irrigation systems. AgriculturalResearch Council - Institute for Agricultural Engineering. RSA.8. Reinders, F.B. 1986. Evaluation of irrigation systems. Directorate of AgriculturalEngineering and Water provision. RSA.9. Reinders, F.B. 1996. Irrigation Systems: Evaluation and Maintenance. SA Irrigation,Vol. 5-7.10. Scott, K. 1997. Designing with Sprinklers. Unpublished literature. ARC- institute ForAgricultural Engineering. Silverton, Republic of South Africa.11. Scott, K. 1998. The effects of wind in sprinkler irrigation. ARC- Institute for AgriculturalEngineering. Republic of South Africa.Asihlumisane Farmers Association Report - 2009 Page - 52 -

12. Solomon K.H. 1988a, Irrigation Systems and Water Application Efficiencies. Centrefor Irrigation Technology, California State University, Fresno, California.13. Solomon K.H. 1988b.A new way to view Sprinkler pattern, Center for irrigationTechnology, California State University, Fresno, California.14. Solomon, K.H. 1990. Sprinkler Irrigation Uniformity, center for irrigation Technology,California State University, Fresno,California.15. Solomon, KH Zoldoske, DF and Oliphant, JC. 1996. Laser Optical Measurement ofSprinkler Droplet Sizes. Center for irrigation Technology, California State University,Fresno, California.16. SSA.2001. Sugar Production Manual. Swaziland Sugar Association. Mbabane17. Zoldoske, D.F. and Solomon, K.H. 1988. Coefficient of Uniformity- What it tells us.Center for irrigation Technology, California State University, Fresno, California.Asihlumisane Farmers Association Report - 2009 Page - 53 -

11 P R O D U C T I N F O R M A T I O NRiver pumps technical details;Sprinkler equipment specifications from the manufactureSoils classification according to SSAAsihlumisane Farmers Association Report - 2009 Page - 54 -

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12 A P P E N D I C E SAttached are the following documentsAppendix 1: SEB usage for river pump station phase 2Appendix 2: capital recovery factors (CRF)Appendix 3: soil map and block layoutAsihlumisane Farmers Association Report - 2009 Page - 60 -

SEB usage for River pump station Phase1Annual WaterWater requirement use 14000m³/Year 103 Total water use in year 1442000 m³/YearMonths Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Des% use per month 8.1 7.7 9.88 9.09 8.79 4.96 2.86 5.43 9.18 11.5 11.95 10.56Watter use per monthmain116802111034142470131077.8126751.8 71523.2 41241.2 78300.6132375.6 165830 172319152275.2Water use per hour 162 154 198 182 176 99 57 109 184 230 239 211Main pumps Needed 1.2 1.2 1.5 1.4 1.4 0.8 0.4 0.8 1.4 1.8 1.8 1.6River Pumps practical 2 2 2 2 2 1 1 1 2 2 2 2kW use for Main Pump 8.3 8.3 8.3 8.3 8.3 8.3 8.3 8.3 8.3 8.3 8.3 8.3Total kVa Demand 33.2 33.2 33.2 33.2 33.2 16.6 16.6 16.6 33.2 33.2 33.2 33.2Total kw use for themonth7457.367089.099096.148368.8138092.6154566.4812633.0924999.1928451.67310587.60811001.919722.186Total Max. Demandcosts2304.742304.742304.742304.7442304.7441152.3721152.3721152.3722304.744 2304.7442304.7442304.744Total kW cost1640.621559.602001.15 1841.14 1780.38 1004.63 579.28 1099.82 1859.37 2329.27 2420.42 2138.88Total Energy Cost /month3945.363864.344305.894145.8834085.1192156.9981731.6522252.1944164.1124634.01774725.1634443.625Asihlumisane Farmers Association Report - 2009 Page - 61 -

SEB usage for Booster pump station Phase 1Annual WaterWater requirement use 14000m³/Year 103 Total water use in year 1442000 m³/YearMonths Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Des% use per month 8.1 7.7 9.88 9.09 8.79 4.96 2.86 5.43 9.18 11.5 11.95 10.56Watter use per monthmain116802111034142470131077.8126751.8 71523.2 41241.2 78300.6132375.6 165830 172319152275.2Water use per hour 162 154 198 182 176 99 57 109 184 230 239 211Main pumps Needed 0.7 0.6 0.8 0.7 0.7 0.4 0.2 0.4 0.7 0.9 0.9 0.8Booster Pumps practical 1 1 1 1 1 1 1 1 1 1 1 1kW use for Main Pump 52.3 52.3 52.3 52.3 52.3 52.3 52.3 52.3 52.3 52.3 52.3 52.3Total kVa Demand 104.6 104.6 104.6 104.6 104.6 104.6 104.6 104.6 104.6 104.6 104.6 104.6Total kw use for themonth27029.822334.928658.3 26366.825496.6114387.178295.82615750.4726627.8633357.34234662.6330630.74Total Max. Demandcosts7261.337261.337261.337261.3327261.3327261.3327261.3327261.3327261.332 7261.3327261.3327261.332Total kW cost5946.574913.686304.83 5800.70 5609.25 3165.18 1825.08 3465.10 5858.13 7338.62 7625.78 6738.76Total Energy Cost /month13207.9 1217513566.213062.0312870.5910426.519086.41410726.4313119.4614599.94714887.11 14000.1Asihlumisane Farmers Association Report - 2009 Page - 62 -

Appendix 2: capital recovery factors (CRF)CAPITAL RECOVERY FACTORS (CRF)Interest RatesYears% 2 3 4 5 6 7 8 9 10 15 205 0.538 0.367 0.282 0.231 0.197 0.173 0.155 0.141 0.130 0.096 0.0806 0.545 0.374 0.289 0.237 0.203 0.179 0.161 0.147 0.136 0.103 0.0877 0.553 0.381 0.295 0.244 0.210 0.186 0.167 0.153 0.142 0.110 0.0948 0.561 0.388 0.302 0.250 0.216 0.192 0.174 0.160 0.149 0.117 0.1029 0.568 0.395 0.309 0.257 0.223 0.199 0.181 0.167 0.156 0.124 0.11010 0.576 0.402 0.315 0.264 0.230 0.205 0.187 0.174 0.163 0.131 0.11711 0.584 0.409 0.322 0.271 0.236 0.212 0.194 0.181 0.170 0.139 0.12612 0.592 0.416 0.329 0.277 0.243 0.219 0.201 0.188 0.177 0.147 0.13413 0.599 0.424 0.336 0.284 0.250 0.226 0.208 0.195 0.184 0.155 0.14214 0.607 0.431 0.343 0.291 0.257 0.233 0.216 0.202 0.192 0.163 0.15115 0.615 0.438 0.350 0.298 0.264 0.240 0.223 0.210 0.199 0.171 0.160Asihlumisane Farmers Association Report - 2009 Page - 63 -

Asihlumisane Farmers Association Report - 2009 Page - 64 -

Asihlumisane Farmers Association Report - 2009 Page - 65 -