Water Policy for Food Security, a global conference

1. WHAT POLICIES TO MANAGE
GROUNDWATER USE IN AGRICULTURE?
Findings from a study on OECD countries
Guillaume Gruère
Senior Policy Analyst
Natural Resources Policy Division
OECD Trade and Agriculture Directorate

2. 1. Groundwater: a great asset for
irrigators
• OECD in 2010: 23mha
of groundwater irrigated
land (33% of irrigated
land) and 123.5km3/yr
(56%) of groundwater
withdrawals for irrigation
• Increasingly used in
irrigation-prone regions
of large groundwater
using countries
Trends in use for top 10 OECD groundwater irrigators
US  Greece 
Mexico  Japan 
Turkey  Australia 
Italy ? Korea
Spain  Portugal ?

3. • Three significant negative externalities of intensive pumping:
– Stream depletion
– Salinity
– Land subsidence
but linked with significant challenges
Dr J. Poland’s picture of land subsidence in Mendota, San
Joaquin Valley, California, USA, 1925-77.

4. • When to intervene?
– Groundwater is often lying
between private property and
common pool resources
– Argue that there may be a
justification for long term
depletion, and to cope with
negative externalities
• What instrument to use?
– No single solution…
2. What does economics tell us?

5. 3. What policies and management
approaches are used in OECD countries?
Direct and indirect, intensive and extensive
regulatory approaches
Economic approaches: pricing, markets, and others
Collective management approaches Supply-side approaches

6. Does this diversity reflect groundwater constraints?
Evidence based on 20 OECD agricultural regions
Relative agro-climatic and other groundwater stresses
Relative
importance of
public
management
approaches
• Systematic comparison and pairwise correlations suggest:
– Regions that exercise less control on groundwater <->higher use and demands
– Economic and supply-side approaches <-> higher groundwater stress
• Still no overall correlation between scope of management and
importance of groundwater stresses

7. 4. What should be done to move
towards sustainable systems?
ALL GROUNDWATER IRRIGATION SYSTEMS
6 general conditions:
Robust information system Favour demand-side instruments
Use groundwater conjunctively Enforce existing regulations first
Favour use of direct approaches Remove perverse incentives
REGIONS WITH INTENSIVE GROUNDWATER USE
A Tripod Approach
1. Entitlement systems and regulations
2. Economic instruments 3. Collective management
REGIONS WITH HIGH STRESS
A) Agronomic tools B) Supply-side instruments

8. Thank you for your attention
• Reference:
OECD (2015), Drying wells, rising stakes: Towards
sustainable groundwater use in agriculture, OECD
Studies on Water, OECD Publishing, Paris.
http://dx.doi.org/10.1787/9789264238701-en
• Websites: http://www.oecd.org/tad/sustainable-
agriculture.htm
– www.oecd.org/water
• Email: Guillaume.Gruere@oecd.org