how design, management and policy affect the performance of irrigation projects

172 Pages·2003·6.72 MB·English

HOW DESIGN, MANAGEMENT AND POLICY
AFFECT THE PERFORMANCE
OF IRRIGATION PROJECTS

EMERGING MODERNIZATION PROCEDURES
AND DESIGN STANDARDS

Hervé Plusquellec

FAO 2002
Bangkok, Thailand
HOW DESIGN, MANAGEMENT AND POLICY
AFFECT THE PERFORMANCE
OF IRRIGATION PROJECTS

EMERGING MODERNIZATION PROCEDURES
AND DESIGN STANDARDS

Hervé Plusquellec

FAO 2002
Bangkok, Thailand

AN ADVOCACY DOCUMENT FOR ALL STAKEHOLDERS:
IRRIGATION AGENCIES, FINANCING INSTITUTIONS,
USER ASSOCIATIONS, PLANNERS, DESIGNERS
AND RESEARCH INSTITUTIONS
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The designations employed and the presentation of material
in this publication do not imply the expression of any
opinion whatsoever on the part of the Food and Agriculture
Organization of the United Nations concerning the legal
status of any country, city or area or of its authorities, or
concerning the delimitation of its frontiers or boundaries.

ISBN 974-680-215-1
RAP 2002/20

All rights reserved, No part of this publication may be
reproduced, stored in a retrieval system, or transmitted in any
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or otherwise – without the prior permission of the copyright
owner. Applications for such permission with a statement of
the purpose and extent of the reproduction, should be
addressed to the Meetings and Publication Office, Food and
Agriculture Organization of the United Nations, Regional
Office for Asia and the Pacific, Maliwan Mansion, 39 Phra
Athit Road, Bangkok 10200, Thailand

© FAO, March 2002
iv
CONTENTS
PREFACE 1
PART I: AN HISTORICAL PERSPECTIVE 13
I. THE CAUSES OF POOR PERFORMANCE OF IRRIGATION
PROJECTS: AN UNFINISHED DEBATE 13
Perceived deficiencies in technical design and management 14
Administrative and behavioural reasons 17
Criticism of engineers 17
Criticism of development banks and donor agencies 19
The slow recognition of design as a main reason of the poor
performance of irrigation systems 21
The dawn of a new approach to irrigation design and management 24
II. PERFORMANCE OF IRRIGATION SYSTEMS 27
III. A REVIEW OF THE ROLE OF INTERNATIONAL
ORGANIZATIONS 31
1. The World Bank 31
The lack of an irrigation policy paper 31
Pressure to lend 32
Use of overoptimistic assumptions during design and appraisal 34
2. The Asian Development Bank 34
3. The FAO Cooperative Programme guidelines 35
Identification and preparation of irrigation projects 35
Updating of the 1984 irrigation guidelines (1996) 37
IV. TECHNICAL VERSUS MANAGERIAL CHANGES 40
V. TECHNOLOGY VERSUS INSTITUTIONAL REFORMS: USER
PARTICIPATION 45
From social to business associations 45
Impact of irrigation management transfer on the performance of
irrigation projects 49
VI. IMPROVED IRRIGATION IN THE CONTEXT OF WATER
RESOURCE MANAGEMENT 52
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PART II: CHANGING APPROACHES TO THE DESIGN OF
IRRIGATION PROJECTS 55

VII. IRRIGATION DESIGN CONCEPTS IN SELECTED COUNTRIES 55

A. Traditional irrigation systems 55
B. Country experience 56
1. India 56
2. Pakistan 58
3. Egypt: the Nile valley system 62
4. Sudan: the Gezira project 63
5. China 66
6. North African countries 68
7. Iran 70
8. Malaysia 72
9. Indonesia 73
10. United States of America 74

C. Use of Bureau of Reclamation design standards in developing
countries 75
D. Cross country transfer of technology 78
India: transfer of rotational distribution from northwest India
to the southern states 79
Transfer of rotational irrigation from India to Thailand and Nepal80
Indonesia: transfer of technology to user-managed systems 81
E. Conclusions 82

VIII. THE FORCES OF CHANGE 87
Response from farmers 89
Response from technology 90
Response from agricultural research 91
Response from the governments 92

IX. THE EXPLOSIVE EXPLOITATION OF GROUNDWATER
RESOURCES 92

X. THE PLANNING PROCESS: A GLOBAL GAME PLAN 95
Definition of modern design 95
Principles of modern design 96
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Proper objective 97
Water delivery 98
Configuration 99
Water control strategy 99
Guiding principles for selecting a control strategy and equipment 103
Modernization of existing schemes 109
Simulation of canal response for different scenarios 109
Centralized automatic control systems 110

XI. PARAMETERS INFLUENCING THE PLANNING AND DESIGN
OF IRRIGATION PROJECTS 111
Water resources 112
Groundwater resources 112
Silt load 114
Rainfall 115
Soil conditions 115
Crop diversification 116
Existing infrastructure 117
Land tenure and consolidation 118
Management and technical capability: the field reality 120
Economics and maintenance costs 120
Institutional setup 121
Operational capabilities of irrigation agencies and user associations 122
Pricing and water allocation strategy 123
Capacity of the construction industry 123

XII. THE CHALLENGE OF MODERNIZATION: OPTIONS
AND PROCEDURES 124
Infrastructure versus management inputs 124
Stepwise versus full-fledged modernization 125
The role of water users’ associations in the modernization process 127
Financing of rehabilitation programmes: a few examples 127
Specific design issues 131
Hierarchy of canals 131
Control of seepage losses 133

XIII. A PROCESS FOR REVISING DESIGN PROCEDURES
AND STANDARDS 135
Assess needs for change: the use of internal indicators 135
Development of new design procedures 138
Revision of design standards 139
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Strategies for dissemination 140
XIV. CONCLUSION: THE NEED FOR COUNTRY IRRIGATION
POLICIES 141

REFERENCES 145

ANNEXES 149
Annex 1: Planning a large irrigation project in the 1950-70 period 149
Annex 2: Abstracts from the FAO Guidelines for Planning
Irrigation and Drainage Investment Projects 151
Annex 3: Conventional terms of reference for consulting services 153
Annex 4: Irrigation policy: modernization of water resources
in Brazil 154

FIGURES
Figure 1: A multi-tier user organization/agency of a surface
irrigation system 49
Figure 2: Alternative configurations of canal automated systems 101
Figure 3: Complexity of different control strategies at design,
construction and operation stages 103
Figure 4: Options for ease of operation and higher levels of service105
Figure 5: Flow rate fluctuations through weir and orifice control
structures 107
Figure 6: Combination of check and turnout structures 108
Figure 7: Land consolidation in an interventionist agricultural
economy 119
Figure 8: A land consolidation model in a liberal agricultural
economy 119
Figure 9: An irrigation project with a well-established hierarchy
of canals 131
Figure 10: A typical irrigation system with a loose hierarchy
of canals and a high number of direct outlets 132
Figure 11: Typical configuration of an irrigation system in Mid
and South China 133

PHOTOGRAPHS*

Photo 1: Dominican Republic I
Photo 2: Viet Nam, Dau Tieng Project I

*All photographs by Hervé Plusquellec unless specified otherwise.
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Photo 3: Viet Nam, Dau Tieng Project II
Photo 4: Pakistan, SWABI Project in North West Frontier Province II
Photo 5: Argentina II
Photo 6: Nepal, Sunsari-Morang Project III
Photo 7: Iran, Guilan Project III
Photo 8: Iran, Guilan Project III
Photo 9: Malaysia, Kemubu Project IV
Photo 10: India, Majalgaon Project IV
Photo 11: Iran, Guilan Project IV
Photo 12: France V
Photo 13: Philippines V
Photo 14: Japan, farm layout before land consolidation V
Photo 15: Japan, farm layout after land consolidation V
Photo 16: Pakistan VI
Photo 17: USA, Salt River Project, SCADA VI
Photo 18: Spain, Cabral Project, SCADA VII
Photo 19: Morocco, Haouz Project (Société du Canal de Provence) VII
Photo 20: Mexico, Rio Fuerte Project VIII
Cover : Vietnam, Dau Tieng Project
Vietnam, Dau Tieng Project (Arjen During)
Internal Cover : Alberta, Canada (Irrigation Secretariat, Alberta
Agriculture, Food and Rural Development)
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PREFACE
Irrigation is in a quiet crisis. Despite undeniable past successes in
contributing to food production, irrigation expansion has
dramatically lost momentum since the 1980s due to a considerable
slowdown in new investment, losses of irrigated areas due to water
logging, salinization, aquifer over-drafting and urban encroachment
in some countries. However, irrigated agriculture still remains
essential for future food security. The reduction of investments in the
irrigation sector is not consistent with the identified needs for future
food security, as indicated by numerous model studies on projections
of food demand and supply. The increasing disinterest of donor
agencies and governments in irrigated agriculture may have dramatic
consequences in the coming years if the situation is not reversed
soon.
One of the factors that have contributed to this disinterest is the
relatively poor performance of large-scale canal irrigation projects.
These systems are the most difficult to manage and have yielded the
lowest returns compared to their expected potential. The paper
emphasizes that performance of irrigation projects is determined by a
combination of physical, institutional and policy factors. It focuses
however on the importance of design and technology that is often
denied or not recognized by decision-makers and others involved in
the development of large-scale irrigation.
This document is rather an advocacy, not a design manual, for
irrigation projects. However, it presents some important suggestions
for the revision of the planning process of irrigation projects and of
operational procedures which have an impact on the selection and
design of water control structures. The paper touches the issue of
projects with conjunctive use of canal and groundwater; but does not
address the design issues of projects making use of groundwater
only. The technical discussion on the design is limited to the
structures found in irrigation projects, which determine water
operation and distribution. It therefore excludes drops, escapes and
communication structures.
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This publication is divided into three main parts. The first part
reviews the various causes of performance of irrigation and drainage
projects below their expected potential as suggested by many
irrigation analysts over the last four decades. This part concludes that
the gap between potential and actual outcome is strongly related to
over-optimistic assumptions on hydraulic performance at planning
stage and in a number of cases to faulty and unrealistic designs. High
overall efficiency can only been reached in well-operated irrigation
systems, which require well-designed and constructed systems.

The second part describes the conventional design concepts and
operational procedures of irrigation projects used in the countries
with large irrigated areas. It then discusses the operational problems
of the design standards used in some countries or resulting from
inadequate transfer of technology.

The third part reviews various factors that should be considered in
the selection of an overall irrigation and water control strategy. The
final chapter proposes a process whereby agencies responsible for
irrigation would review existing design procedures and standards in
view of existing and future requirements in terms of service and
performance. Agencies would have to assess the needs for change
and the development of new design standards and procedures. The
chapter concludes with a strategy for the revision and dissemination
of revised guidelines.

***

This publication, its analyses and considerations, are global in scope,
although naturally Asian irrigation, its history and characteristics as
well as transfers of technology to and within the region are
extensively covered. We believe that the publication and its
recommendations are particularly relevant to Asia. For this reason,
the FAO Regional Office for Asia and the Pacific has undertaken to
commission and publish this work.

Present developments in the irrigation sector in Asia are dominated
to a large extent by Participatory Irrigation Management (PIM) and
2