The World Bank and Irrigation

Abstract

This document follows a review written by the Operations Evaluation Department staff and consultants. It examines more than four decades of World Bank irrigation experience, especially the Bank's irrigation lending, which has accounted for seven percent of all lending. The study focuses on 208 Bank-funded irrigation projects that have been evaluated and it chiefly addresses two questions: 1) what has the Bank's irrigation policy been? and 2) what have been the returns on irrigation investments? Sixty-nine percent of all lending has gone to humid tropical Asia, where irrigation systems are used chiefly to grow rice; while the other 31 percent of Bank lending for irrigation has been split between Africa, the Americas, and Europe. Evaluations have rated 67 percent of irrigation projects satisfactory overall. At appraisal, the economic rate of return on irrigation investments was expected to average 22 percent. The average unweighted evaluation rate of return was 15 percent. When projects are weighted by size of area served, the appraisal expected rate of return was 29 percent; the evaluation rate of return, 25 percent. Therefore, the overall impact of Bank-financed irrigation projects has been relatively good. The factors that most significantly affect the outcome of irrigation projects are the size of the irrigated area, output price, crop yield, and unit cost. In the Bank's irrigation sector work, for the sample analyzed, little attention has been paid to environmental planning, specifically to wather allocation and natural resource planning, but the situation is improving. Sector report coverage of specific areas of environmental impact has been poor and is still quithe weak. The study finds that irrigation projects got a 12 percent higher level of supervision per year than the average Bank project and the average implementation delay for irrigation projects, 1.7 years, was only slightly above the average for all projects. Based on the findings of this study which highlight what has or has not worked and the evolution of Bank policies, recommendations for changes in policy on Bank-supporthed irrigation investments are made.