Drying wells, rising stakes : towards sustainable agricultural groundwater use.

176 Pages·2015·7.558 MB·English

by  OECD

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Chapter 1. The worrisome trends in groundwater irrigation expansion t
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Chapter 2. Understanding agricultural groundwater systems and challenges
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Chapter 3. What policy instruments help to manage agricultural groundwater use sustainably?
Chapter 4. What agricultural groundwater policies exist in OECD countries? gROunDWaTER uSE
Chapter 5. Towards adaptive groundwater management in agriculture
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Consult this publication on line at http://dx.doi.org/10.1787/9789264238701-en. u
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iSbn 978-92-64-23869-5
51 2015 12 1 P

OECD Studies on Water
Drying Wells, Rising
Stakes
TOWARDS SUSTAINABLE AGRICULTURAL
GROUNDWATER USE
This work is published under the responsibility of the Secretary-General of the OECD. The
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Please cite this publication as:
OECD (2015), Drying Wells, Rising Stakes: Towards Sustainable Agricultural Groundwater Use, OECD
Studies on Water, OECD Publishing, Paris.
http://dx.doi.org/10.1787/9789264238701-en
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Series: OECD Studies on Water
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3
FOREWORD –

Foreword
As a natural reserve relatively resilient to climate variability, groundwater has provided large
benefits to irrigated agriculture in semi-arid OECD countries. It has supported the development and
expanded production of commodity crops in the US Midwest and Mexico and high value products in
semi-arid areas of Mediterranean Europe or the Middle East. But intensive use beyond recharge
capacity in certain regions has depleted resources and increasingly generates significant negative
environmental externalities, including stream depletion, saline intrusion and land subsidence.
The report studies the challenges of managing groundwater use in agriculture sustainably,
acknowledging its increasing importance as a tool for agriculture’s adaptation to climate change. It
provides new data on the status of groundwater irrigation, proposes a characterisation of
groundwater agricultural systems, assesses the economic effects of existing management instruments
and analyses the range of policies used in OECD countries.
The study builds on OECD’s work on water, especially the 2010 report overseeing issues around
the sustainable management of water resources in agriculture, the 2014 report on climate change,
water and agriculture, and the 2015 survey-based analysis of water resource allocation regimes in
OECD countries.
The analysis relies on new information collected through a comprehensive questionnaire of
groundwater management policies in OECD countries and selected regions launched in the summer of
2014. Contributions from OECD delegations and OECD country experts in responding to this
questionnaire are gratefully acknowledged.
This report was written by Guillaume Gruère. Chapter 3 is based on a consultant report written by
Nicholas Brozovi , Robert B. Daugherty Water for Food Institute and University of Nebraska-Lincoln,
United States. Noura Takrouri-Jolly provided statistical support at different stages of the project and
contributed significantly to the design, implementation and analysis of the OECD questionnaire. The
report also benefited from comments and suggestions from Dale Andrew, Nicholas Brozovi , Carmel
Cahill, Anthony Cox, Kathleen Dominique, Jane Ellis, Julien Hardelin, Franck Jésus, Hannah Leckie,
Xavier Leflaive and Janine Treves. Michèle Patterson edited and formatted the report. Françoise
Bénicourt and Stéphanie Lincourt helped manage the administrative process.

DRYING WELLS, RISING STAKES: TOWARDS SUSTAINABLE AGRICULTURAL GROUNDWATER USE © OECD 2015

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TABLE OF CONTENTS –

Table of contents

Executive Summary ......................................................................................................................................... 9
Chapter 1. The worrisome trends in groundwater irrigation expansion .................................................... 11
Key messages ............................................................................................................................................ 12
The increasing significance and challenges of groundwater irrigation ..................................................... 13
Groundwater use in agriculture accounts for over half of OECD countries’ total groundwater
withdrawals, with large differences across countries ............................................................................... 16
From groundwater use to groundwater stress ......................................................................................... 24
Expected effects of climate change: Increased reliance on groundwater, reduced recharge and
increased salinity ....................................................................................................................................... 28
Notes ......................................................................................................................................................... 31
References ................................................................................................................................................. 33
Annex 1.A1. Agricultural activities supported by groundwater in OECD countries .................................. 39
Annex 1.A2. Groundwater use: 2010 estimates and national trends in other OECD countries ............... 40
Annex 1.A3. Explanatory note on Margat and Van der Gun (2013) data.................................................. 42
Chapter 2. Understanding agricultural groundwater systems and challenges ........................................... 45
Key messages ............................................................................................................................................ 46
A need to move beyond the wide heterogeneity in agricultural groundwater systems .......................... 47
Characterising agriculture groundwater systems in OECD countries ....................................................... 48
Key implications of groundwater use in agriculture ................................................................................. 55
Notes ......................................................................................................................................................... 63
References ................................................................................................................................................. 65
Annex 2.A1. Existing typologies on groundwater and irrigation systems ................................................. 69
Chapter 3. What policy instruments help to manage agricultural groundwater use sustainably? ........... 73
Key messages ............................................................................................................................................ 74
Looking for efficient and effective management solutions....................................................................... 75
Scope for public action: Managing long-term depletion and externalities ............................................... 75
Choice of policy instruments: A wide range of options ............................................................................ 77
What factors count in the choice of instruments? .................................................................................... 79
Demand-side policy instruments to manage groundwater use ................................................................ 82
Supply-side approaches: Relieving the constraints for users, at a cost .................................................... 89
Synthesizing lessons from the economics literature: A call for adaptive management policies .............. 90
Notes ......................................................................................................................................................... 91
References ................................................................................................................................................. 94
Annex 3.A1. Analytical model .................................................................................................................... 99
Annex 3.A2. Case study: choice of policy instruments for groundwater management .......................... 103

DRYING WELLS, RISING STAKES: TOWARDS SUSTAINABLE AGRICULTURAL GROUNDWATER USE © OECD 2015
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– TABLE OF CONTENTS

Chapter 4. What agricultural groundwater policies exist in OECD countries? ......................................... 107
Key messages .......................................................................................................................................... 108
An analysis based on findings from a 2014 OECD survey on groundwater management approaches .. 109
A wide spectrum of agricultural groundwater management approaches .............................................. 111
Are policy instruments corresponding to specific groundwater characteristics? Findings
from a regional analysis........................................................................................................................... 130
Notes ....................................................................................................................................................... 135
References ............................................................................................................................................... 137
Annex 4.A1. Deriving regional indicators of groundwater characteristics and management ................ 145
Annex 4.A2. Results of the regional indicator analysis ........................................................................... 149
Chapter 5. Towards adaptive groundwater management in agriculture ................................................. 153
Key messages .......................................................................................................................................... 154
Drawing recommendations from successes, failures, and lessons learned ............................................ 155
An increasing need for a more sustainable management of groundwater resources
to face a changing climate ....................................................................................................................... 162
Notes ....................................................................................................................................................... 166
References ............................................................................................................................................... 167
Glossary ....................................................................................................................................................... 171

Tables
Table 1.1. Estimated global groundwater stocks, inflows and withdrawals ....................................... 18
Table 1.2. Major aquifer systems in OECD countries .......................................................................... 22
Table 1.3. Estimated renewable groundwater development stress (GDS) for selected aquifers
in OECD countries ............................................................................................................... 26
Table 1.4. Identified concerns for groundwater resources under climate change in OECD countries30
Table 1.A1.1. Scale of groundwater irrigation for selected field crops in the United States .................. 39
Table 1.A2.1. Groundwater areas and estimated use in OECD countries as of 2010 .............................. 40
Table 2.1. Three classes of aquifers .................................................................................................... 49
Table 2.2. Comparing the main socio-economic typologies ............................................................... 50
Table 2.3. Proposed characterisation of agriculture groundwater irrigation systems ....................... 55
Table 2.4. Main reversible and irreversible consequences of intensive groundwater abstraction .... 57
Table 2.A1.1. IGRAC groundwater regions in OECD countries and their characteristics ......................... 69
Table 2.A1.2. Proposed typology of groundwater economies by Shah et al. (2007) ............................... 71
Table 2.A1.3. The GW-MATE typology of groundwater systems ............................................................. 72
Table 2.A1.4. Proposed typology of groundwater and surface water resources use in irrigation
depending on climatic conditions ...................................................................................... 72
Table 3.1. Main types of instruments used to manage groundwater use in agriculture ................... 79
Table 3.2. Linking energy policies and groundwater use .................................................................... 88
Table 3.3. From economics to policy: Comparing instruments to manage groundwater .................. 90
Table 4.1. Coverage of received responses to the groundwater questionnaire .............................. 110
Table 4.2. Groundwater entitlement characteristics by responding regions or countries ............... 112
Table 4.3. Estimated number of unauthorised or illegal wells in selected countries ....................... 120
Table 4.4. Regional coverage of the OECD questionnaire ................................................................ 132
Table 4.5. Selected indicators of groundwater resource characteristics and policies by regions .... 133
Table 4.A1.1. Definitions of the variables used to represent the characteristics of
the groundwater system .................................................................................................. 145
DRYING WELLS, RISING STAKES: TOWARDS SUSTAINABLE AGRICULTURAL GROUNDWATER USE © OECD 2015
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TABLE OF CONTENTS –

Table 4.A1.2. Definitions of the variables used to represent the characteristics of
the groundwater system .................................................................................................. 146
Table 4.A1.3. Formulas used to compute the indicators ....................................................................... 148
Table 4.A2.1. Indicators on the main resource and use characteristics for the fifteen regions ............ 149
Table 4.A2.2. Indicators on policy approaches ...................................................................................... 150
Table 4.A2.3. Pairwise correlation across selected indicators ............................................................... 150
Table 5.1. Proposed management package for intensive groundwater use .................................... 158
Table 5.2. Countries and regions that implement the groundwater management package ........... 163

Figures
Figure 1.1. Proportion of groundwater use by sector in OECD countries (2008-2013) ....................... 19
Figure 1.2. Area irrigated with groundwater and proportion of total irrigated areas
in OECD countries (2010) ................................................................................................... 19
Figure 1.3. Estimated groundwater abstraction for agriculture irrigation (2010) ............................... 20
Figure 1.4. Groundwater abstraction for agricultural use, by area, in OECD countries (2010) ........... 21
Figure 1.5. Trends in total groundwater withdrawal for agriculture in selected OECD countries
(1985 -2010) (km3/year) .................................................................................................... 22
Figure 1.6. Schematic representation of groundwater discharge and recharge ................................. 23
Figure 1.7. Global distribution of groundwater resources ................................................................... 24
Figure 1.8. Estimated average groundwater development stress in OECD countries (2010) .............. 25
Figure 1.9. Quantitative status of groundwater bodies in selected OECD EU countries under the
Water Framework Directive (2009).................................................................................... 27
Figure 1.10. Changes in groundwater levels in two major US aquifer systems ..................................... 28
Figure 1.A2.1. Agriculture groundwater use in other OECD countries from 1985 to 2013 ...................... 41
Figure 2.1. Schematic representation of the evolution of groundwater-irrigated agriculture systems51
Figure 2.2. Groundwater and surface water uses ................................................................................ 54
Figure 2.3. Patterns of groundwater abstraction ................................................................................. 56
Figure 2.4. Proportion of responding regions withdrawing groundwater for agriculture in OECD
countries, with at least one externality ............................................................................. 57
Figure 2.5. Schematic representation of surface water groundwater interaction .............................. 59
Figure 2.6. Main sources of groundwater salinity ................................................................................ 60
Figure 2.7. Elevation change computed from repeat geodetic surveys along the Delta-Mendota
Canal (left NW-right SE) ..................................................................................................... 62
Figure 3.1. A cross-sectional diagram of interactions in a linked surface water-groundwater system 77
Figure 3.B1. High Plains Aquifer region and selected groundwater administration areas .................. 104
Figure 3.B2. Comparison of the cost-effectiveness of alternative policies for reducing stream
depletion impacts in the URNRD, Nebraska..................................................................... 105
Figure 4.1. Simplified map of groundwater allocation systems in the United States, as of 2005 ..... 114
Figure 4.2. Geographical levels of subnational groundwater management among responding
countries........................................................................................................................... 116
Figure 4.3. Number of OECD countries or regions using specific groundwater regulations .............. 117
Figure 4.4. Number of responding countries reporting the use of agricultural water conservation
(left panel) or irrigation efficiency programs (right panel) with groundwater effects .... 123
Figure 4.5. Number of countries or regions with collective management schemes
by drivers (left panel) and scale (right panel) .................................................................. 124
Figure 4.6. Supply-side programs supporting alternative water supplies or storage ........................ 126
Figure 4.7. Number of responding countries and regions with land policies related
to groundwater ................................................................................................................ 128
DRYING WELLS, RISING STAKES: TOWARDS SUSTAINABLE AGRICULTURAL GROUNDWATER USE © OECD 2015
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Figure 4.8. Number of responding countries with climate change adaptation (upper panel)
and drought insurance programs (lower panel) .............................................................. 130
Figure 4.9. Comparing relative groundwater stress and policy approaches in
the responding regions .................................................................................................... 135
Figure 4.A2.1. Comparison of standardised indicators of groundwater characteristics in the 20 regions151
Figure 4.A2.2. Comparison of groundwater management and policy indicators in the 20 regions........ 152
Figure 5.1. Expected climatic evolutions in responding regions by climate (number of responses) . 164

Boxes
Box 1.1. Basic elements of groundwater flows ................................................................................ 23
Box 2.1. Five main types of aquifers ................................................................................................ 48
Box 2.2. Four working rules of groundwater irrigation .................................................................... 52
Box 2.3. Surface and groundwater irrigation ................................................................................... 53
Box 2.4. Groundwater withdrawal induced land subsidence in OECD countries ............................ 61
Box 3.1. A simple model of human-natural interactions in an aquifer ............................................ 77
Box 3.2. Applying analytical models to address stream depletion: Examples from
the United States ................................................................................................................ 82
Box 4.1. Groundwater allocation in the United States: A patchwork of systems .......................... 114
Box 4.2. Managing groundwater at the sub- river basin level:
The EU Water Framework Directive ................................................................................. 115
Box 4.3. Well permits and conflicting positions: The case of potatoes in PEI, Canada .................. 118
Box 4.4. Rural-urban water and financial transfers to address groundwater overdraft ............... 127
Box 5.1. Redressing groundwater externalities: The Tablas de Daimiel National Park in Spain .... 157
Box 5.2. From policy to implementation: What governance system for groundwater? ............... 161
DRYING WELLS, RISING STAKES: TOWARDS SUSTAINABLE AGRICULTURAL GROUNDWATER USE © OECD 2015