Drying Wells, Rising Stakes Towards Sustainable Agricultural Groundwater Use OECD Studies on Water
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OECD Studies on Water OECD Studies on Water Drying Wells, Rising Stakes TowArds SUstAINABLE AGRICULTURAL GroUNdwAter Use OECD Studies on Water Contents Chapter 1. The worrisome trends in groundwater irrigation expansion Drying Wells, Rising Stakes Chapter 2. Understanding agricultural groundwater systems and challenges Chapter 3. What policy instruments help to manage agricultural groundwater use sustainably? TowArds SUstAINABLE AGRICULTURAL Chapter 4. What agricultural groundwater policies exist in OECD countries? GroUNdwAter Use Chapter 5. Towards adaptive groundwater management in agriculture Drying Wells, Rising Stakes Drying Stakes Rising Wells, T ow A rds SU st AINABL E A G R I C UL T U R AL AL Gro UN dw A ter Consult this publication on line at http://dx.doi.org/10.1787/9789264238701-en. Use This work is published on the OECD iLibrary, which gathers all OECD books, periodicals and statistical databases. Visit www.oecd-ilibrary.org for more information. 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 opinions expressed and arguments employed herein do not necessarily reflect the official views of OECD member countries. This document and any map included herein are without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and boundaries and to the name of any territory, city or area. 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 ISBN 978-92-64-23869-5 (print) ISBN 978-92-64-23870-1 (PDF) Series: OECD Studies on Water ISSN 2224-5073 (print) ISSN 2224-5081 (online) The statistical data for Israel are supplied by and under the responsibility of the relevant Israeli authorities. The use of such data by the OECD is without prejudice to the status of the Golan Heights, East Jerusalem and Israeli settlements in the West Bank under the terms of international law. Photo credits: Cover © Eddie J. 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FOREWORD – 3 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 TABLE OF CONTENTS – 5 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 ...................................................