MODERNIZATION OF IRRIGATION SCHEMES
This website of the Regional Office for Asia and the Pacific of the Food and Agriculture Organization of the United Nations is dedicated to the modernization of irrigation systems.
On this website, you will find:
News on events, publications, training courses, projects, updates of the website, etc. Website subscribers can post their related news on this website by contacting the webmaster
Tools for use in the appraisal, benchmarking and upgrading of irrigation systems for modernization and their upgrading.
Training materials and programmes on operation and management, modernization and benchmarking of irrigation schemes. Training materials can be consulted on-line and downloaded from the website.
Publications from FAO on modernization of irrigation schemes and links to relevant publications form other agencies and publishers. FAO publications can be downloaded for free from the website.
Technical briefs and papers on technical, strategic and policy aspects of irrigation modernization.Technical briefs submitted by subscribers of the website will be uploaded on the website after review by the website manager.
Links to related sites, projects, organizations and databases.
By signing up to the website, you can participate in the web-board, get news on modernization activities and website updates, receive new FAO products on irrigation system modernization, post news and technical documents, have a link on the website to your website, organization or project.
Although the website is primarily destined for use by the irrigation and drainage professional community of Asia, it is believed that most of the documents, methodologies, tools and training materials available on the site will be of interest to professionals from other regions. It is hoped that the web-board of the site, links and technical briefs will facilitate the exchange of information among the professionals of Asia and other regions.
KEY IDEAS AND CONCEPTS ON THE MODERNIZATION OF IRRIGATION SYSTEMS
Rehabilitation vs modernization
Modernization as understood in this website.
Modernization of an irrigation system can be defined as:
the act of upgrading or improving the system capacity to enable it to respond appropriately to the water service demands of the current times, keeping in perspective future needs.or
a process of technical and managerial upgrading (as opposed to mere rehabilitation) of irrigation schemes with the objective to improve resource utilization (labor, water, economics, environmental) and water delivery service to farms.or
the transition from supply-oriented to service- oriented irrigation water delivery.
The modernization process involves institutional, organizational and technological changes and implies changes at all operational levels of irrigation schemes from water supply and conveyance to the farm level. The objective is to improve irrigation services to farmers and improvements in canal operation will generally be a critical first step in the process. Users have to take the final decisions on the modernization programmes and improvements should not stop at the canal level.
Irrigation sector reform and improving the service to farmers
The notions of service and vision and anticipation of future service and performance requirements for the future modernization of agriculture and the transition to integrated water resources management are central to the concept of modernization. The notion of water delivery service and of generalized service-orientation of institutions in the irrigation sector, whether river basin agencies, reformed irrigation agencies, irrigation service providers, water users associations has become central in the sector and in new concepts and definitions of participatory irrigation management and irrigation management transfer.
The evaluation of impacts of on-going participatory irrigation management and irrigation management transfer programmes is one of the reasons of this evolution as literature on the evaluation of impacts of on-going programmes in terms of water service delivery, agricultural productivity and agricultural performance indicates that improved service is a problem area. The service orientation of irrigation water delivery doers not appear to be sufficiently taken into account in processes and tools for design and preparation of operation and maintenance plans infrastructure rehabilitation works, monitoring and evaluation systems. For the large systems, partial or gradual transfer may not provide explicit steps for a real decision on service and the gradual building upstream of governance structures by federation a constraint to address the central strategic questions of service at the beginning of the transfer process. For small or traditional schemes, the question of future needs of irrigated agriculture is often not asked. IMT has rarely affected the design processes. The sustainability of the water users associations is however now seen to depend on their capacity to provide an adequate water delivery service and control and to allocate water and to provide an improved service to enable gains in agricultural productivity.
In the context of Asia, diversification of rice crops is a major issue for increased income by farmers and improved agricultural and water productivity. This in turn is essential for the capacity of farmers to pay water and the water users associations to e financially viable. As a result, it is now recommended that strategies of gradual improvement of irrigation systems be adopted to support the transfer of water management responsibilities and associated rights. Concepts of irrigation management transfer/participatory irrigation management transfer and modernization are therefore converging.
However, there are still some substantial differences: modernization stresses that the infrastructure/physical improvements which must be supported must be designed with a view to improve equity and reliability of water delivery service and evolve towards increasing levels of flexibility. Operational and technical details become very significant. Environmental considerations need to be better taken into account in a perspective of integrated water resources management.
A more forward-looking strategy anticipating future needs is required. Recent visioning processes in the water sector provide a good condition for strategically planning organizational and technical changes in participatory and irrigation management.
Actual irrigation and water management
Stated vs. actual water management
Intended or stated water management of a system is often very different from actual water management. Service requirements of the farmers are often met from other sources than the intended delivery of the main surface systems. Yet, in spite of an affirmed service orientation, Irrigation Management Transfer programs often fail to take into account actual needs as expressed by farmers' actual practices, or actual water management and new institutions appear to reflect stated operations of the canal systems and not the need for combined management of water delivery, drainage, water recycling and conjunctive use.
The actual systems
Initial concepts of extensive irrigation used for the development of irrigation were adapted to the conditions of unregulated supply and objectives of irrigation of the time. Later design standards in many countries to deliver water according to crop demand were more advanced but most of the systems fail to meet that objective. Agricultural performance has been affected by deficiencies in the water control technology and the complexity of operational procedures. Managing existing actual systems is often a very complex and difficult task. Systems designed for operation at full capacity without consideration for operation at less than full supply simply cannot work.
How farmers responded and why they will always respond in the same manner.
Farmers responded to economic changes, poor or inadequate service, insufficient flows for intensive irrigation by trying to achieve required flexibility, reliability and volumes to adopt modern cultivation practices and diversification or freedom in cropping patterns and strategies: illegal water trading within distributaries, tampering of control structures, tapping additional resources, pumping from canals, drains, borrow pits etc. The explosion of groundwater irrigation is largely a farmer response to the lack of flexibility and, in the worst cases, the unreliability of the canal irrigation systems. Water recycling and the conjunctive use of groundwater are also often an efforts from managers to rectify problems of management capacity and design shortcomings.
These responses from the farmers are inevitable. If the water distribution rules define a pattern of water distribution that does not match feasible and desired goals of the water users, they will subvert these rules. Inconsistency in water distribution rules is likely to lead to inefficient and inequitable water distribution. Operations in the upper levels of management must improve if water users associations are to be in a position to develop applicable rules and procedures. The need for change in response to changing environment and agriculture, etc. requires adapting water distribution rules. Users, on the other hand, must accept the limitations imposed by water availability and system features: but these can be changed. Production objectives of the farmers must be incorporated at all levels. Slow adoption of new on-farm irrigation technology in developing countries also points to the lack of attention to the level of operation of the main and conveyance systems: farmers will not invest in water saving technologies if service is not reliable or flexible enough.
Design processes have been a problem in the past.
Performance of irrigation projects is determined by a combination of physical, institutional and policy factors. The gap between potential and actual outcome is strongly related to over-optimistic assumptions of the hydraulic performance at planning stage, and in a number of cases to faulty and unrealistic designs as well as construction or by the capacity of the management agency to apply the operational rules defined by the designer. Many designs are difficult to manage under real field conditions.
The professional context explains why design engineers know little about actual distribution processes. Some of the reasons lie in administrative and behavioral reasons, mostly associated with lack of experience, accountability and feed-back from operation of design engineers and lack of accountability of operators and managers to the users. In countries with large development of irrigation, state officials have often entrenched engineering practices. The question whether the technical/hydraulic dimension of irrigation can be brought under the control of agents focused on non-technical user-derived objectives is central. Reassessing the design standards, configuration and operational procedures at the moment of transfer as a result of a review or resetting of both internal objectives in terms of service with the water users and external objectives with water resources management institutions is necessary.
Irrigation Management Transfer (IMT) corrects the root cause of the problem but not the existing infrastructure.
Participatory irrigation management and irrigation management transfer reforms often have the stated objectives of providing sustainable and adequate financing for operation and maintenance of irrigation and drainage services and of facilitating investment in the required rehabilitation or upgrading of irrigation systems. Overall reform of water resources management often encompasses these reforms. It often includes demand management to encourage efficient water allocation and imposes new externalities on irrigation systems in terms of environmental performance.
IMT provides an opportunity to correct the institutional, administrative and behavioral reasons at the stages of design, construction and operation but institutional measures cannot right all the wrongs. Many problems of the existing schemes related to inequity and unreliability of water service can be attributed to design and operational procedures, some of which cast in concrete, which, if left unchanged, will produce the same results whatever the governance setup. Irrigation projects have progressively changed from a project-specific nature to take the form of sector loans or national/regional projects which support the objectives of participation and capacity building, and often include low cost rehabilitation or differed maintenance of irrigation infrastructure. This cannot correct the deficiencies of the original design, if the causes of deficiencies are not identified through an in-depth diagnosis of the current system. In practice, rehabilitation often simply re-establishes the physical configuration of the original system.
In Asia, where the older public schemes reach the age of 30-40 years in most countries, the issue of rehabilitation, which is related to those of operation and maintenance and modernization, is becoming increasingly important. While for some countries the extension of irrigated land still represents an important part of irrigation programmes, in most countries rehabilitation programmes are taking on increasing importance. The content and orientation of rehabilitation in a context of PIM/IMT will therefore be critical.
Modern design processes.
Modern design results from a process that selects the configuration and the physical components in light of a well- defined and realistic operational plan, which is based on the service concept and uses advanced concepts of hydraulic engineering, agronomy and social science to arrive at the most simple and workable solution.
The most important issue is the system ability to achieve a specific level of operational performance at all levels within the system. A proper operational plan is the instrument that combines the various perspectives and helps reconcile conflicting expectations between the users, the project manager, the field operators and the country policy objectives. The second step is the decision about water deliveries i.e. the flexibility (frequency, rate and duration) of water deliveries at all levels of an irrigation system. The decision on the flexibility at all levels and ultimately at the farm is the most important decision as flexibility distinguishes and characterizes classes of service quality from rotation to on-demand and is most closely related to improvements in agricultural performance, crop diversification, etc. Service agreements together with strategic management are increasingly adopted to encapsulate the iterative decision process on level of service and associated financial decisions, accountability and monitoring and evaluation processes as well as plans to upgrade management and infrastructure into a continuous management process.
Design and degrees of freedom in distribution.
A water delivery schedule does not imply a specific design. A rigid schedule of water deliveries to the farms may use modern irrigation hardware and computerized decision support systems to make water deliveries reliable and equitable, but a project designed for rigid rotation or proportional distribution through simple non-adjustable structures cannot be operated for flexible water distribution. Existing layout, original design criteria and standards used for an irrigation project limit the options for its rehabilitation and modernization. In extensive irrigation projects, design capacity decreases from upstream to downstream while it increases to accommodate the need for flexibility in responsive irrigation projects.
Design for IMT, Integrated water resources management, policy reform and design and operation.
Water rights and the necessity to satisfy different water uses with the same primary infrastructure will also become a major issue, together with obligations related to disposal and quality of effluents and other environmental requirements. The trend is to transfer the management of large sections of irrigation systems to large user associations, such as in Turkey and Mexico. The contractual approach to bulk supply provision or irrigation service provision may require changes in hardware and operational rules at the interface with precise, but user-friendly, control of flows and measurements of volumes. If management of the main system has to be divided between units, the interface should be located at hydraulic "breakdowns" such as reservoirs. Reforms often include the establishment of water rights and trade of these rights, and the pricing of water on a volumetric basis. The design of irrigation projects should take these reforms into consideration. The layout of the canal network should also be designed so as to be integrated with not only the roads and drainage system, but also with the multi-levels of management.
Appraisal of initial conditions and performance.
An appraisal of initial conditions and performance of the systems to be transferred would allow both a better design and strategic planning of physical improvements together with a definition of the service to be provided both by the irrigation service provider to WUAs and by WUAs to their members, with indications on ways and means to achieve these service goals and improve them in the future. Operation rules should be transparent and understood by the users.
Rehabilitation, modernization and Irrigation Management Transfer: the problem of infrastructure.
IMT programs commonly include efforts to rehabilitate, upgrade or modify infrastructure. IMT entails changes in governance of the systems for goal setting, which includes the decision on the service to be provided by the system. Relevant to IMT would also be among others the determination or choice of cropping patterns (previously by the agency).
Field processes for planning rehabilitation and upgrading.
IMT processes are meant to be somewhat demand-driven. The most common tool for planning or rehabilitation/improvement works is the walk-through. PRA mapping, transects, of land tenure, farming systems, ecosystems are also common. In practice, a diagnosis of operation procedures is usually not performed and operational rules and procedures are not really discussed or linked to repair works. Physical works are not related to service or performance goals. Expectations are low. The initial focus on upgrading is generally on reliability and equity, which are admittedly the first issues to be addressed but there is generally no vision of future requirements. There is no discussion of flexibility, the main aspect of service quality.
Outputs of current design and planning processes in Asia.
In Asia, impacts are typically not noticeable in terms of agricultural performance: change in irrigated area, crop patterns, cropping intensity or yields and PIM has neither improved nor interfered with agricultural productivity. The future of farming is seen to depend on diversification of crops and a more commercial orientation. The necessity of reengineering irrigation, i.e. taking a fresh look at key processes and how they can best be carried out and of considering both hardware and software elements is emphasized but this is in apparent contrast with typical design processes and their outcomes.
Gradual improvement strategies.
PIM has generally led to modest efforts by farmers to improve management efficiency and responsiveness. Under-investment in O&M is also observed. It is therefore recommended to replace periodic rehabilitation with gradual on-going infrastructure improvements, with the objective to improve performance and ensure financial viability and physical sustainability of irrigation. Financial instruments that allow farmers to invest in the upgrading of their irrigation systems become critical. Decentralized irrigation improvement funds to provide matching funds from Government are increasing proposed in IMT programmes.
Other regions have often adopted a radically different approach.
In contrast with this model, IMT in other regions has often taken a very different shape, with a deliberate effort to change the control logic of the systems from the top down and the transfer of large units of the systems to large water users associations. IMT has been more engineering driven, and this is the main difference with Mexican, Turkish, US experience. The issue is whether basic flaws or constraints can be addressed with a light rehabilitation program and whether not doing so hampers IMT/PIM or jeopardizes the success of reform in terms of sustainability of institutions and financial sustainability.
Management of irrigation systems
New management requirements.
One must understand the internal mechanisms of irrigation systems, and enhance those internal mechanisms, if project performance is to be improved. These "details" (such as communication, procedures etc.) are important: investments should arguably be based around specific actions to improve them, rather than deciding on the framework for detail improvement only after the investment is approved. Management of irrigation systems in a service oriented mode is also a complex operation and requires advanced managerial skills and the ability to process and interpret large amounts of data. Managers including WUA managers need modern information and management systems in order to perform their new tasks.
Monitoring and evaluation.
After IMT, the Irrigation Service Provider decides with the users what services should be provided, what their objectives and target should be, what service performance standards are acceptable. As IMT modifies the organizational arrangements for providing the service, it must be evaluated in terms of the quality of that service. In current monitoring and evaluation systems, key issues about outcomes and impact include as potential immediate outcomes the quality of the water delivery service. Possible impacts are related to socio-economics and productivity. Areas of interest for water users are quality and cost of O&M, use of funds collected, agricultural and economic productivity. Impacts include cropping intensity, number of crops grown, congruence of operational rules with farmers' goals. M&E is meant to provide information but also to strengthen local management capacity, enhance skills and support problem solving by WUAs with tools like inspection of irrigation systems for planning of maintenance or rehabilitation priorities, preparation of O&M plans etc. In the service concept, these outcome and impact indicators are actually the specific objectives of service-oriented management.
External performance and internal process indicators.
External indicators examine values such as economic output, efficiency, and relative water supply (i.e., ratios of outputs and/or inputs). Targets are set relative to objectives of system management, and performance measures tell how well the system is performing relative to these targets. These indicators are applicable to compare actual results with what was planned or to compare performance among pears with similar characteristics. Internal process indicators assist managers to improve water delivery service to users. They include indicators to assess processes and concretely measure service at all levels and could be very useful in M&E systems.
Irrigation management audits, asset assessment and management, benchmarking.
Benchmarking, which uses primarily external performance indicators, could be introduced as a way for continuously assessing management performance before, during and after IMT and maintaining a dynamic of improvement. Irrigation management audits can be used to assess performance according to key indicators listed in a service agreement. Where infrastructure is still owned by the government after IMT, they can be a joint exercise between the irrigation agency, WUA and local government to assess governance and service provision, including technical, financial and organizational aspects. A prerequisite for management audits is a detailed initial assessment of assets to be transferred with their condition and functionality, and systematic monitoring of assets through detailed survey and monitoring.
The case for a massive re-training of engineers and managers in irrigation agencies, consulting firms and Irrigation Service Providers
Intensified and on-going training programmes for both professionals in the reformed irrigation agencies, consulting firms who will provide advisory services to water users associations and to the managers of water users associations and the technical staff that they may employ for operation and maintenance of their irrigation schemes are understood as one of the conditions for sustained success of the transfer programmes.
It is therefore essential that these programmes introduce and provide knowledge on ways and means to design and operate irrigation systems cheaply for good performance and adequate service to farmers as they evolve toward more commercial forms of agriculture. An appraisal of initial conditions and performance of the systems to be transfer would allow both a better design and strategic planning of physical improvements together with a definition of the service to be provided both by the irrigation service provider to WUAs and by WUAs to their members, with indications on ways and means to achieve these service goals and improve them in the future. It is suggested that the Rapid Appraisal Procedure developed and used in the evaluation of modernization programmes could be used for this purpose at programme appraisal stage and for individual irrigation systems.
A pilot training programme on modernization concepts and application of the Rapid Appraisal Procedure, which builds on the knowledge synthesis acquired in recent years on modern design principles and participatory irrigation management shows promising results from the frist training workshops held in Thailand, Viet Nam, Indonesia and the Philippines.
In most of Asia, rice is not only the staple food, but also constitutes the major economic activity and a key source of employment and income for the rural population. Water is the single most important component of sustainable rice production, especially in the traditional rice-growing areas of the region. Reduced investments in irrigation infrastructure, increased competition for water and large water withdrawals from underground water lower the sustainability of rice production. However, despite the constraints of water scarcity, rice production must rise dramatically over the next generation to meet the food needs of Asia's poor. By year 2025, rice production in Asia must increase by 67 percent from the 1995 production level in order to meet the increased demand for this cereal which is the staple for more than one-half of world's population. Producing more rice with less water is therefore a formidable challenge for the food, economic, social and water security of the region.
About 80-90 percent of all freshwater resources used are for agricultural purposes and more than 80 percent of this water is used in irrigating rice. In other words, the efficiency of water use in irrigated rice production systems must be significantly increased. The existing strong interdependence between water use in the crop production subsystem and the operation of the irrigation facilities for water service elicits the need for pursuing a comprehensive agenda for improving the performance of rice irrigation systems.
Since no major net addition to currently irrigated rice areas is expected in the coming decades and major breakthroughs in raising yields of rainfed rice systems are unlikely to be available during this period, most of this additional rice will have to be produced in irrigated areas. In rice irrigation systems, rice monoculture is overwhelmingly the dominant practice. Diversification of the crop production system in these areas is desirable for several reasons. First, diversification will open opportunities for increasing farmers' income from their limited land resources. This is particularly important at the present time when profits from rice culture are very low and declining. Second, it is increasingly evident that, as productivity of the land under rice monoculture under wetland conditions is declining over time, a diversified agriculture will be more sustainable in the long run. Third, with increasing scarcity of water, irrigated agriculture will have to aim at maximizing return to water rather than return to land. Present rice culture systems require more water than most other food crops, both in terms of quantity of food and calorie produced. Therefore, a major scope exists for increasing returns from water by growing diversified crops, especially in areas of water shortage. To enable farmers to diversify their cropping pattern, they must be provided with facilities to exercize crop choice options, which is presently lacking in most rice irrigation systems.
Upgrading rice schemes
The task of upgrading or modernizing an irrigation system for rice cropping in the wet season and for diversified cropping in the dry season is complex. It requires that any permanent structural or physical upgrading to be done for rice must also conform to the requirements of the diversified crops to be grown in the dry season. It is therefore logical to assume that the upgrading of common denominator factors, i.e. factors that are relevant for both seasons, could be upgraded permanently and these should be handled by the main irrigation system. Examples of these would include upgrading of water control, drainage, reliable schedule of water delivery, etc. at the main system. The on-farm, crop-specific factors could be handled seasonally by the farmers themselves as individuals or as groups. Examples of this type of upgrade would include the same items, as above, but at the farm level. Provision of flexibility will become an additional requirement.
Reliable water supply is critically important for diversified cropping, as farmers have to invest much more for these crops compared to rice. Areas that are far from the irrigation source generally suffer more water shortage in the dry season compared to near-by areas. Means of augmenting water supply in these areas, if they are suitable for diversified cropping, have to be found. Shallow groundwater development through the private sector is often the most reliable and affordable water source for this purpose. Groundwater has the advantage of being available on demand at the farm and able to avoid major water distribution problems.
Suitable methods of water application to the crop (e.g., basin, furrow or basin-cum-furrow), methods of controlling seepage from canals or neighboring rice areas (e.g., dikes, interceptor channel, dike-cum-interceptor channel), or means of drainage enhancement (e.g., collector gravity drain, pumping, collector-cum-pumping) will be required. Diversified cropping requirements must be thoroughly considered in pursuing the modernization process, with the objective of raising farmers' incomes through provision of flexibility and option to choose crops in the dry season.
Water management for rice
As far as rice water management itself is concerned, whether one aims at raising water productivity or water use efficiency, it is now widely accepted that a river basin perspective should be adopted with much more attention being paid to defining the boundaries of intervention (farm, system, basin). Substantial progress has been made in defining concepts and methodologies (water accounting, modeling, etc.) but available data, which are already woefully inadequate to assess the merit of interventions at the farm or system level, water abstraction and even cultivated and irrigated areas, are even more lacking for the adoption of integrated river basin approaches. More attention must also be paid to water quality issues and particularly the release of pollutants (fertilizers and other agro-chemicals) and salt concentration.
Nevertheless, practices which minimize irrigation inflow are of a direct interest to farmers who see their water supply rationed and have to pay an increasing share of its cost, for managers and developers who also face rationing because of degradation of water resources, dam siltation, transfer to other sectors, etc. and have an interest in minimizing pumping costs, and operation and maintenance as well as development costs, and indeed for water resources managers who need to plan future irrigation developments with minimum environmental impact from withdrawals or reservoirs. In addition, many major rice-growing areas are located in coastal plains. Furthermore, water saving practices, which require greater water control, typically are associated with or part of packages to improve agronomic practices and the efficiency of use of other inputs, and therefore play an important role in total factor productivity. They therefore contribute to increasing not only water use or irrigation efficiency but also to improving or sustaining water productivity.
Indeed, water management methods, which improve water use efficiency, have been developed with a view to maintain crop yields and actually, when implemented properly, lead to yield increases (in the range of 15-20% in China for intermittent flooding and other methods). It follows that, although it is correct and necessary to use rigorous concepts for efficiency and performance at system and basin levels, and to determine under various conditions the optimum combination of improved technologies and water management practices that can meet water demand with least water consumed and managing return flows to ensure system and basin level efficiency, in practice it is difficult to find water management techniques proposed for adoption at the farm level which do not simultaneously raise irrigation efficiency and water productivity. The acceptance by farmers of these strategies and practices will of course depend on economic factors. Furthermore, they depend on improved water control and management of water at the system level, as well as adequate irrigation (in particular a reticulated irrigation distribution system) and drainage facilities. Their availability in China has allowed farmers to adopt the water savings techniques. However, typically, at that level, conveyance, field canal and distribution efficiencies are particularly sensitive to the quality of management, communication and technical control. When water supply within the system is unreliable, farmers try to store more water than is needed. In many large irrigation systems, few control structures at any level and poor drainage structures and poor drainage networks contribute to a waste of water.
Being confronted with this rather large number of problems, it is not surprising that farmers are reluctant to shift to more demanding water management techniques than flooding. However, considering the growing water scarcity and pressure on the irrigated sub-sector within the water sector and on agriculture by other sectors of society and overall economic development policies described in previous sections, there is not much choice and farmers must be provided both with a conducive environment and a proper production tool, i.e. better performing irrigation services.
An evaluation of previous modernization projects
Improvements in the operation and maintenance of rice irrigation schemes through rehabilitation of the deteriorated systems, improvement of irrigation infrastructure for surface irrigation, irrigation management transfer, modernization, combining to various degrees institutional, organizational and technical changes, have been attempted in the region with mitigated degrees of success. Studies undertaken by the World Bank in recent years have evaluated the impact of irrigation projects. A study of 1995 evaluated the design of rice project in the humid tropics and concluded, from the strong degree of resistance of farmers to new design standards and the level of anarchy and chaos observed on the schemes, that the more reticulated systems, capable of supporting on-demand water delivery, were not appropriate under these climates. A more recent study (1997) assessed the agro-economic impacts of investments in gravity-fed irrigation schemes in the paddy lands of Southeast Asia, to determine whether and how the quality of O&M services influences the sustainability of those impacts.
At four of the six sites, the areas supplied by the irrigation systems were significantly less than planned. Cropping intensities were also substantially lower than expected at three sites and falling at a fourth. Only one scheme had attained both its area and intensity targets. Paddy yields varied widely -between schemes and in comparison with expectations- but a weighted average for the wet and dry seasons at all the schemes was about 3.3 tons, or 85 percent of appraisal projections. However, farmers had not diversified out of paddy. Indeed, the concentration on paddy had increased. Output was between 32 and 73 percent of appraisal estimates for five schemes. The returns had also been driven down by the decline of the international price of rice.
Overall, agency and irrigator performance appeared to be substantially better than expected. Farmers cooperated to achieve at least basic O&M objectives regardless of the level of maturity of the formal organization. There were no substantial negative constraints on irrigated production attributable to poor performance in O&M. Those O&M operations that are essential to keep sufficient supplies of water flowing to the great majority of the fields were adequately carried out. The study also noted the dismantling of complex technological control systems installed in the 1980s in favor of fixed structures that have no adjustments and structures that adjust automatically to changes in water levels; the rejection by farmers of both rotations and gates. Rotations do occur, but they tend to break down under conditions of shortage, which is when they are most needed. The main finding was that given that they offered poor economics and low incomes, these paddy irrigation schemes faced an uncertain future. Small-holder irrigated paddy could no longer provide the basis for a growing, or even stable, household economy, driving younger family members off the farms while older members who stayed behind concentrated on basic subsistence crops, social capital would erode and O&M standards were likely to suffer. As economies expanded, irrigated paddy would not be able to compete with the incomes to be had from other employment opportunities. Improved O&M performance would not rescue them.
The study made these recommendations:
- Sharpen the response to O&M failures by disaggregating O&M; identifying the poorly performing components; and dealing with disincentives specific to each, such as the tertiary gates that farmers below consider unfriendly.
- Simplify the infrastructure and operations technology by converting to fixed and automatic controls that need less human intervention and by supporting authorities that plan with the farmers to abandon equitable rotations by rationing water during emergencies.
- Promote the transfer of management to farmers and their WUGs judiciously by recognizing that organizing user groups pays off, but also accepting that immature WUGs cannot handle some management responsibilities.
- Improve household earnings by diversifying cropping systems and supporting research, extension, and marketing services keyed to specialty crops and integrated, high-value farming.
The findings and conclusions of these two studies, combined with the results of the evaluation of modernization projects conducted by IPTRID in 1998, seem to be rather pessimistic and contradictory. However, put together, they tend to indicate that present project designs or operations are not capable of supporting both economically and technically the intensified, diversified and more water efficient and productive rice production systems which will be required in the future. They also seem to indicate that purely software solutions or mere improvement of operation and maintenance do not deliver the expected results in terms of improvements in performance and yields. They also reveal that many modernization or improvement efforts have been inappropriate, poorly adapted to local circumstances and the specific character of rice-based production systems, and incomplete or fragmentary. Conjunctive use is practiced within "modern" irrigation schemes: it may provide a solution but is not available in all places.