PERFORMANCE EVALUATION OF IRRIGATION SCHEMES TO IMPROVE LAND & WATER PRODUCTIVITY: A CASE STUDY OF RAJANGANA IRRIGATION SCHEME IN SRI LANKA S M D L K De Alwis 1 and N T S Wijesekera 2 ABSTRACT The Present study of Rajangana major irrigation scheme using a 12 year dataset captured a holistic picture of seasonal irrigation productivity on a water management unit basis with 11 indicators covering Service Delivery, Agriculture Production, Agriculture Economics and Financing. Water use efficiency measured by System Water Delivery Service and Irrigation Duty were 1.13 and 1.992 m/ha, respectively. MOM cost/unit area and Maintenance Budget Implementation measuring the average efficiency of performance level in operation and maintenance were 60.11% and 94.02%. Average agriculture productivity was 4.073 Mt/ha, having average efficiency of performance at 91.53%. Cropping Intensity measuring the land productivity reflected full performance with an average value of 2.01. Average water productivity of 0.102kg/m 3 was far below the benchmark of 0.372kg/m 3. Average efficiency of the performance in Resource Utilization and Profit were 47% and 61.36%. System sustenance levels focusing on irrigation infrastructure maintenance with twonew indicators namely Beneficiary Involvement and Government Involvement showed that over the study period, annual contribution to system sustenance declined at a rate of 3.06% and 6.0%respectively, with average efficiency in performance of 49.81% and 68.78% indicating system deterioration. Keywords: Water, food, climate, performance, intervention, productivity. 1. INTRODUCTION Irrigation and drainage provide essential service to irrigated agriculture by providing and removing water to suit the crops' needs. The potential national average yield of paddy for the year 2005 was estimated at 4.1 MT/ha (Dhanapala, 2000). The yield of paddy had been recorded as 4.8 Mt/ ha for major irrigation schemes, 3.8 Mt/ha in minor irrigation schemes and 3.35 Mt/ha for rainfed in year 2007 (Imbulanaet al., 2010). Water productivity of rice farming in the world ranges from 0.15-0.6 kg/m3 where the value in the South Asia is lower than the 0.4 kg/m 3 (Cai and Rosegrant, 2003). However with the district average yield in the study area which measures the water productivity as 0.372kg/m3 i.e 62% of the world potential and 75% of the national potential which was computed by getting the estimated value of 7.61 Mt/ha of Agriculture Department. Performances of irrigation schemes must be evaluated by considering their key operations affecting to water use, operation & maintenance, agriculture productivity, land productivity, water productivity, resource use efficiency, farmer status and system sustenance. Reviewing the current assessment programme and available performance indicators adopted at various locations ID 2003, Bos, Burton and Molden 2005, Malano and Burton 2001, Murray-Rust and Snellan 1993 and learning them, a performance assessment programme was developed with eleven performance indicators (Alwis and Wijesekara, 2011) to conduct as a research to evaluate the 1 Director, (Water Resources Management), Ministry of Irrigation and Water Resources Management, Irrigation Department of Sri Lanka. 2 Senior Professor of Civil Engineering, Department of Civil Engineering, Univ. of Moratuwa, Sri Lanka. 1
performance of major irrigation scheme in Sri Lanka by using available set of data from year 1990 to year 2002 of LB Tract 01 area in Rajangana major irrigation scheme out of 25 tracts located in the scheme ( Fig 1 ). Figure 1. Study Area in Rajangana Major irrigation Scheme 1.1 Need for Performance Assessment and Objective of the Study There are numerous inter related causes affecting the efficiency and productivity of a scheme. The typical questions that require addressing under a performance assessment programme is (i) How well are the Irrigation performances of a Tract being operated? (ii) What is the productivity of T.O. area in an irrigation scheme? and (iii) What is the level at which the Irrigation practices are being performed and the identification of profitability of paddy cultivation in economic terms?. The selected 11 performance indicators provide sufficient information to address all these questions at once with less data recording and collection procedures. The objective of the study was mainly focused to identify the issues and constraints affecting the yield and income of farmers through an evaluation of the use of irrigation water, cultivation practices and productive use of lands for cultivation. In this connection critical study was performed to do the evaluation of case study area giving due consideration to the following specific objectives. (i) (ii) (iii) (iv) To assess current water use efficiency, irrigation practices and land productivity of a study area. To diagnose the constraints which lead to poor performance of an irrigation system. To present proposals to improve the efficiency and productivity of an irrigation system. To propose a suitable performance assessment programme by a critical evaluation selecting required indicators. 2. METHODOLOGY As the first step, comprehensive study on literature was conducted. An initial screening of literature was done to capture those indicators considering importance of Turnout level monitoring, capability to compute either with presently collected data or with acceptable estimation from scheme level or guideline information. Special 2
attention was given to minimize the cost of data collection and to avoid carrying out special measurements unless the stakeholders expressed a pressing need. Data & information were processed and statistical analysis was done to obtain the operational performance of LB Tract 01 area to diagnose the constraints in water use efficiency, operational performance and the productivity. Some quantitative measurements were converted in to the qualitative parameters by looking at the aspects of performance assessment in eight domains under four important sectors of assessment programme. The overall performance assessment in the case study area classified under the four important categories related to service delivery in the scheme and the land and water productivity in a simplified approach and holistic manner is presented. Format was developed to present the results of the performance assessment programme. Conclusion and recommendations were made based on the findings of analysis. 3. DATA COLLECTION, PROCESSING AND CHECKING Spatial and temporal data pertaining to FC1A, FC1B, D-01 and D-02 turn out areas in the LB tract 01 were collected for a period of 12 years, focusing the assessment of efficiency, and productivity of the area. Data collection was done using different techniques basically literature survey, field survey, formal group discussion, informal group discussions and through questionnaire survey to capture the unavailable real time data to cover the study period. Some institutional and financial data related to study area too were gathered for the assessment of operational and financial performance of the study area and those data were made use to compare with the data of other available institutions. Apart from that decision was taken to use regional values of the data published by the various departments to complete the study assuming accuracy of them are still remain in the range of validity specially for values of monthly ET0, Crop Factors, densities of soils, irrigation canal efficiencies, rate of percolation and initial soil moisture content etc. Based on the preliminary data collection ( Alwis and Wijesekara, 2011), to assess the performance and quantify the values of listed performance indicators primary and secondary data were identified against each indicator and all variables were taken in to consideration which affects the end results. Data collected at the field and offices were compared with other surveyed data collected by various institutions and it was found that deviation of some of them were within plus or minus 10% 4. FINAL RESULTS OF OPERATIONAL PERFORMANCE ASSESSMENT Results of the selected eleven indicators chosen under each domain of assessment were taken in to the format (Table 2) depending on the evaluation criteria. Average, maximum and minimum values of each indicator obtained during the analysis were noted to assess the performance level of the study area. In view of organizing the data to present a coherent or consistent picture, some indicators are selected to evaluate under qualitative measurements. Average efficiency of performance were measured based on the marking system adopted for those indicators. Others are evaluated based on directly measured values. Average efficiency values were obtained based on optimum attainable condition decided during the analysis. Having examine final results of each indicator, it was able to assess the performance of study area pertaining to service delivery, agriculture production, agriculture economics & financing and system sustenance. The overall efficiency of the study area was measured as 65.29%. Performance assessment through diagnostic analysis of a problematic area provides solution to overcome the problem and reporting the solutions on time to update the operational plan. Achieving that requirement final result of the assessment as shown 3
in annex2 provide necessary information of the performance assessment programme of L.B. Tract 01 area of Rajangana scheme. These information are made use to conclude the study with recommendation. 5. CONCLUSION AND RECOMMENDATION Results of the 11 performance indicators selected for final assessment of L/B tract 01 area in Rajangana irrigation scheme represent the full picture on irrigation system performances under 8 domains. These selected indicators provide adequate information of system productivity and efficiency and much better approach to evaluate the irrigation system performances of major irrigation schemes in Sri Lanka. In addition to the operational performance indicators used, other indicators described under the productivity performance and financial performance could be used to improve the effectiveness of management strategies to prepare and execute seasonal operation plan (SOP) at a higher efficiency limits in future. As per the point of view of the Irrigation Engineers in-charge of the scheme, no excess water deliveries could be expected other than the requirement. A seasonal adequacy rate above 1.0 is not a problem at all but less than that may develop water stress to the plant. Therefore analyzing SWDS on weekly basis is needed to avoid water stress at high sensitive stages of the crop that is in the mid stage from panicle initiation to reproductive stage. Operation and maintenance of the irrigation system is a most important factor to the system sustenance. Currently there is less allocation is available for O &M allocated and amounts decrease year by year. The expected target of the government to transfer the ownership of the irrigation system in view of obtaining high involvement on O & M of farmers has not flourished. Management intervention measures have to be introduced alone with the capacity building of FOO members in order to change this situation. There is a surplus in paddy production and price is declining as a result. This is a cause for concern as revenue does not justify the investments. The only solution to this is to increase the grain mass of production per unit area introducing high yielding varieties with proper land and water management and high agriculture technology. The conclusions arrived by this study is made used to put forward following recommendations. It is proposed to replicate this performance assessment program with further fine tuning to the other tracts in Rajangana irrigation scheme and to the other Irrigation Schemes in the Island to establish regional bench mark values to formulate a generalized performance assessment program. To monitor SWDS, flow monitoring units should be established. These units should be equipped with communication system. The required structural intervention and adequate training for staff concerned should be provided. With proper monitoring of irrigation management practices cropping intensity could be increased to 3.0 by introducing an intermediate crop season with short term OFCC varieties. Stake holder participation and farmer consultation should be improved by introducing efficient planning and management interventions. This could be done on selected pilot project areas and expanded to other required localities. Government intervention for upgrading system O & M should be increased with the political support. 4
Table 1. Indicator Classification Service Delivery, Agricuture Production, AgricultureEconomics& Financing and System Sustenance No Performance Indicators Unit Definition Domain of Assessment Service Delivery 1 System Water Delivery Service (SWDS) (Irrigation Water Delivered+ Effective Rainfall + Other Inflow) / Intended Water Delivery 2 Irrigation Duty m / ha Volume of Water Issued to Turn out Area / Area Cultivated 3 MOM Cost per Unit Area 4 Maintenance Budget Implementation Rs/ha Management, Operation and Maintenance Cost/ Command Area serviced by the System Annual Expenditure on Maintenance / Annual Money Allocated for Maintenance Agriculture Production 5 Yield Mt/ha Crop Production / Cropped Area 6 Cropping Intensity 7 Water Use 8 Resource Utilization Area Cultivated during the Year/ Command area under the Turnout Kg/ m3 Crop Production / Volume of Water Supplied in Season Agriculture Economics and Financing Value of Production / Cost of Production 9 Profit Rs/ha Income - Expenditure System Sustenance 10 Beneficiary Involvement Contribution by Farmer organization / Government Contribution to Farmer Organization 11 Government Involvement Contribution by the Government / MOM Cost Water Use efficiency Water Use Operation and Maintenance Operation and Maintenance Agriculture Land Water Resource Use efficiency Farmer Status Institutional Development Institutional Development Evaluated Target Criteria Adequacy, Equity and Utility Operational Viability, Sustainability Production Production Profitability Operational Viability, Sustainability Operational Viability, Sustainability 5
Remarks FC 1A, D 02 - "High"/ FC 1B, D 01 - "Medium" FC 1A - "High" / FC 1B, D 01 - "Low" / D 02 - "Medium" Based on 1990 MOM Cost per Ha. Based on annual allocation vs. annual expenditure. Based on district average Based on area cultivated Based on Bench mark value 0.372kg/m 3 Based on farmers data Based on district average profit. Based on annual expenditure of FO & ID Based on annual expenditure of FO & ID Ave.Eff( %) 68.67 54.33 60.11 94.02 91.53 100.00 33.33 25.00 67.83 49.81 68.78 64.85 Table 2 Results of Final Assessment in LB Tr. 01 Marks No. 1 2 3 4 5 6 7 8 Domain of the Assessment Water Use O & M Marks Agriculture Land Water Resource use Farmer Status System Sustenance Indicator 1. SWDS (Adequacy) 2. Irrigation Duty (m/ha) 3. MOM Cost / Unit Area (Rs/ha.) Min m Max m D 02 D 01 FC 1B FC 1A 1.82 0.71 2.32 1.60 1.96 2.36 8.24 3.03 1.358 2.64 1.12 1.00 1.76 1.985 733.41 365.95 - - - - - 102.95% 76.46% - - - - - 98.16 53.63 2.48 2.04 2.56 2.68 9.76 2.2 1.90 - - - - - 0.165 0.048 1.00 1.00 1.00 1.00 4.00 1.31 1.16 - - - - - 10328.95-666.38 - - - - - 96.38% 25.06% - - - - - - 50.92% Average 79.96% 4. M.B.I. (%) 5. Yield (Mt/ha) 6. Cropping Intensity 7. Water Use (kg/m 3 ) 8.ResourceUtilization (W.O.F.L.) 9. Profitability (W.O.F.L) (Rs./ha) 10. Beneficiary Involvement (%) 11. Government Involvement (%) Ave. 1.13 1.97 567.00 94.02% 74.93 2.01 0.102 1.25 5399.95 49.81% 68.78% 6
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