Towards a Framework for Irrigation System Improvement

Towards a Framework for Irrigation System Improvement This unpublished prĂŠcis suggests that, given the dwindling sources of new water and decreasing returns to new irrigation, ADB should shift emphasis from financing new irrigation projects to improving existing irrigation systems and, accordingly, that it should develop a capability for setting priorities for irrigation system improvement.

Olivier Serrat 03/10/1995

1 Introduction 1.

This prĂŠcis underscores the need to increase food supply in Asia and the Pacific and submits that a major part of incremental requirements will have to be met from irrigated land.

However, several factors limit the possibility of meeting incremental requirements through new irrigation projects and rehabilitation and improvement of existing irrigation systems will have to play an important role in the future. The prĂŠcis suggests that the Asian Development Bank should develop a capability for establishing priorities for irrigation system improvement and proposes that regional technical assistance be used for the purpose.

Rising Food Requirements 2.

Total population in Asia and the Pacific is projected to grow from 2.6 billion in 1985 to about 3.3 billion in 2000 and about 4.4 billion by 2025. This assumes that the current annual growth rate of 2.1 percent will slow to 1.9 percent by 2000 and fall further to 1.1 percent by 2025.

Despite lower population growth rates, however, an additional 350 million and 1.5 billion people will need to be fed by 2000 and 2025, respectively, bearing in mind that approximately 50 percent of the current population are still below the poverty line and that more than 300 million are chronically malnourished. According to the Food and Agriculture Organization (FAO), food production is projected to increase at about 3 percent per annum to 2000, slightly below demand, thus making the region a net importer of food. Import requirements will become more substantial or average food intake will decline if assumed food production increases are not realized.

3.

The key constraint on the supply of food meeting demand is reduced availability of arable land. While cropping intensities already average about 108 percent, there is little room for expansion, particularly when losses of arable land to urbanization and degradation are taken into account. Sizable land reserves now exist only in Cambodia, Indonesia, the Lao People's Democratic Republic, Malaysia, and Myanmar. Apart from problems of land availability as such, much land in South and Southeast Asia, estimated at about 85 percent, is affected by shallow and poor soils, steep topography, low water-holding capacity or impeded drainage, or seasonal drought and flooding. At the same time, land degradation continues and substantial parts of arable land in Bangladesh, the People's Republic of China, India, Nepal, Pakistan, and Thailand are affected by water and wind erosion, salinity, or flooding.

4.

Irrigated areas are by far the most productive areas with an output several times higher than non-irrigated areas due to double- or even triple-cropping and higher yields per crop.

Irrigation has been a key factor behind the Green Revolution together with high-yielding varieties and inputs of fertilizer and other chemicals. However, irrigation has not been without problems due to faulty design and management leading to waterlogging, salinity build-up and decline in soil fertility. Furthermore, even high-yielding varieties developed for favorable conditions appear to have reached a yield plateau and raising yield levels will require further strategic breeding.

5.

Whether food requirements scenarios turn out to have been conservative or exaggerated, the additional output required will in any case be so great that a large part of the incremental requirements will have to be met from irrigated land and, possibly, rainfed land under favorable production conditions. This can, hopefully, be done by closing the yield gap still available in the fields of inefficient farm operators and possibly through new plant types or hybrids with still higher yield potentials. There can be no doubt, however, that irrigation investment, mainly through rehabilitation and improvement of existing irrigation systems, will have to play a significant role.

2 Trends in Irrigation Development 6.

In Asia and the Pacific, the area of land irrigated increased from about 85 million hectares in 1966 to about 137 million hectares in 1991, an overall increase of about 60 percent. The past decade, however, has seen an overall decline in the rate of growth in irrigated area. The factors that contributed to the decline in the rate of growth in irrigated area include the large public and foreign debt loads carried by most of the agriculturally based economies in the region, the declining share of unexploited irrigation development potential in many countries, political resistance from those displaced or otherwise negatively affected by irrigation development, growing awareness of environmental problems, preoccupation about issues of sustainability, growing competition for increasingly scarce water supplies, the drop in world commodity prices and the escalation in the cost of developing new irrigated land. These factors make it less likely that new irrigation projects will be started and further expansion of irrigation will in most countries depend largely on improved management of existing water supplies rather than on the development of additional supplies.

Irrigation System Improvement 7.

A sensible alternative to further expansion is investment in improving the performance of existing irrigation systems. Because such projects can take advantage of substantial sunk costs in existing irrigation systems, they are usually significantly cheaper than new construction projects and could provide large production benefits and a concomitant increase in rural incomes.

Production benefits would come about through improvements in hydrological efficiency. In this respect, several sources of gain exist. The first relates to making irrigation deliveries to farmers more predictable, which would have both direct and indirect effects on output. The second relates to the saving of water that is not used productively and the application of water where it will have the greatest impact. The third source of gain stems from the reduction of waterlogging and salinity problems.

8.

Irrigation system improvement projects can be classified into two types, namely, rehabilitation projects that emphasize new investment to improve physical facilities and thereby increase output performance, and management improvement projects that emphasize the development and application of new operating procedures and staff training to accomplish this end. Rehabilitation projects, however, should not aim simply to restore projects to their original design specifications. Because there is now less pressure to design and promote intensive and comprehensive interventions, rehabilitation projects provide greater opportunity to experiment with more selective, lower-cost rehabilitations that require intensive engineering and social and economic analysis. In the same vein, in recognition of the need for changes in the design, existing irrigation systems should also be modernized in the rehabilitation process drawing in particular on the experience of the farmers who have been using the systems for the last 10 or 20 years.

Management improvement projects, on the other hand, recognize that ineffective management of publicly operated irrigation systems is a fundamental cause of poor performance that must be addressed directly if performance is to improve. Such projects focus on farmer involvement in irrigation system operation, on-farm water management and the performance of public irrigation bureaucracies.

9.

The goal of both types of irrigation system improvement projects at the sector level, however, should not be exclusively limited to increasing output performance. Although the immediate objective of irrigation projects should continue to be an increase in agricultural production and an improvement in the economic and social conditions of the beneficiaries, both rehabilitation and management improvement projects offer by their very nature ample scope for

3 further incorporation of social and environmental considerations in project design and provide thereby good opportunities for the achievement of ADB's strategic development objectives.

Setting Priorities for Irrigation System Improvement 10.

ADB's Medium-Term Strategic Framework for the period 1995–1998 sets out the operational agenda for ADB over the medium term and defines its strategic development objectives. These are: (i) promoting economic growth; (ii) reducing poverty; (iii) supporting human development (including population planning); (iv) improving the status of women; and (v) sound management of natural resources and the environment. As suggested above, ADB investment in irrigation system improvement can be expected to contribute in varying degrees to the achievement of all its strategic objectives but perhaps most significantly to the four strategic development objectives of economic growth, poverty reduction, sound management of natural resources and the environment, and improving the status of women. Especially because the climate for development assistance is highly constrained and the prospects for a recovery are poor, however, ADB's resources should be deployed judiciously according to priorities. Therefore, ADB should develop a capability for setting priorities for irrigation system improvement.

11.

The need to develop such a capability and the benefits that can be expected do not require emphasis. For example, careful identification of irrigation systems to be rehabilitated, improved impact assessment methodologies and selection of high-payoff points of intervention within the systems would enable ADB to improve the cost-effectiveness of these interventions. In addition, reform of sectoral institutions such as public irrigation agencies, communal management through water user associations and property rights systems, together with development of water markets and water pricing mechanisms, would improve the efficiency of water allocation. In addition, increased emphasis on the development of cost-effective projects would reduce waterlogging and salinity problems and arrest degradation of irrigated area. Likewise, because irrigation systems frequently suffer from degradation in their catchment areas, irrigation system improvement would provide good opportunities for improving catchment areas.

12.

In view of the above, ADB should consider implementing a regional technical assistance to help set priorities for future operations in irrigation system improvement. The main objective of the technical assistance would be to identify the general principles for identification, prioritization, and selection of irrigation system improvement projects in Indonesia, Pakistan, Bangladesh, and the Philippines, all of whom have been important recipients of ADB assistance to the irrigation sector, based on ADB's Medium-Term Strategic Framework for the period 1995–1998, ADB's strategic development objectives and, for the four developing member countries covered under the technical assistance, with due regard to the country operational strategy studies developed for these countries. The analysis would cover review of ADB's operations in the irrigation sector so far, including Project Performance Audit Reports, Sector Syntheses of Post-Evaluation Findings, Country Syntheses of Post-Evaluation Findings, and Impact Evaluation Studies. The output of the technical assistance would be a framework for investment in irrigation system improvement in the four developing member countries concerned.

The views expressed in this prĂŠcis are those of the author and do not necessarily reflect the views and policies of the Asian Development Bank, or its Board of Governors or the governments they represent.