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Drying Wells, Rising Stakes  Towards Sustainable Agricultural Groundwater Use

Drying Wells, Rising Stakes Towards Sustainable Agricultural Groundwater Use

(2016)

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Book Details

Abstract

Groundwater has provided great benefits to agriculture irrigation in semi-arid OECD countries, but its intensive use beyond recharge in certain regions has depleted resources and generated significant negative environmental externalities. The report provides a characterisation of the diversity of groundwater systems, reviews policies in OECD countries, and proposes a package of recommendations to ensure that groundwater can sustain its services to agriculture and contribute to climate change adaptation.

Table of Contents

Section Title Page Action Price
Cover Cover
Table of contents 5
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 irrigation expansion: A silent revolution 13
Leading to increasing pressures in areas of intensive irrigation 14
Identifying policy solutions to address the growing and diverse challenges of groundwater resource management in agriculture in OECD countries 15
Groundwater use in agriculture accounts for over half of OECD countries’ total groundwater withdrawals, with large differences across countries 16
The challenges of collecting information on an “invisible” resource 16
Agriculture groundwater use in OECD countries: From non-users to major irrigators 18
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
Groundwater use for livestock and aquaculture 39
Groundwater use for irrigated crops 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
Estimating values of annual groundwater abstraction (year 2010) 42
Estimating the break-down of annual groundwater abstraction (year 2010) 43
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
Existing aquifer typologies 48
Main criteria of importance for OECD agriculture 52
Proposed characterisation 54
Key implications of groundwater use in agriculture 55
Extraction cost externalities 57
Environmental externalities 58
Stream depletion (surface water-groundwater interaction) 58
Groundwater salinity 60
Land subsidence 61
Agricultural irrigation effects on groundwater recharge 63
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
A simplified economic model to develop key intuitions 79
Adjusting agricultural groundwater use to limit overall aquifer depletion 80
Dynamic management to control aquifer depletion or stream depletion 81
Demand-side policy instruments to manage groundwater use 82
Regulatory instruments: Pumping entitlements, quotas and zoning 83
Economic instruments: Redressing farmers’ incentives 83
Pricing: The efficiency-acceptability trade-off of taxes and subsidies 84
Groundwater markets: Cost effective but involves transaction costs 85
Indirect control: Irrigation entitlements retirements is a conservation tool whose cost depends on targeting 86
Collective management approaches: Locally adapted but reliant on stakeholder participation 87
Other related conditions for effective groundwater management: Enforcement and policy alignment 87
Monitoring and enforcement: A key necessary condition for functional policy frameworks 87
Interaction with other policies: Aligning energy and agriculture policies 88
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
Case 1: Static model 99
Case 2: Simple dynamic model 100
Annex 3.A2. Case study: Choice of policy instruments for groundwater management 103
Results 105
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
Demand-side management approaches: Shared core approaches, diverse instruments 111
Different legal status and entitlement characteristics stemming mostly from legal traditions 111
Widely used management plans and groundwater regulations, often operating at the sub-national level, face enforcement challenges 114
A growing interest in economic approaches, especially market mechanisms 120
Partial use of collective management approaches, covering a mixes set of schemes and drivers 123
Supply-side approaches: An increasing interest in storage options 125
Other sectorial policies affecting groundwater use 127
Few countries tax or subsidise electricity 127
Half of respondents apply land policies with implications on groundwater use 128
Several watershed conservation programs indirectly affect groundwater use 129
A growing set of climate change adaptation plans, some drought insurance programs 129
Farm support policies generally not biased towards water intensive crops 130
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
Limited reporting evidence, but multiple lessons from the literature 155
Conditions for an effective groundwater management 155
Proposed policy package for sustainable management: A “tripod” combination 157
Are these recommendations used in current policy frameworks of OECD countries? 161
An increasing need for a more sustainable management of groundwater resources to face a changing climate 162
Notes 166
References 167
Glossary 171