Agricultural Water Management: The Key to Food Security in a Changing World

David MoldenInternational Water Management Institute

Water Scarcity 2000

1/3 of the world’s population live in basins that have to deal with water scarcitySource: Comprehensive Assessment of Water Management in Agriculture, 2007

Other Water Pressures

Urbanization - Cities are projected to use 150% more water in 2025

Agriculture – Water fuels production increasesPopulation & Diet – food grain production

projected to increase by 100% by 2050Energy – Hydropower and biofuels compete for

water and landClimate Change – Shifting patterns of water

availability – potential yields decline in Africa

Drivers of Water Use

River basins closed – Colorado, Murray Darling, Yellow, Indus, Amu Darya ……… no additional water left

Groundwater overdraft – in agricultural breadbaskets

Fisheries – ocean and freshwater at a limit, aquaculture will become more prevalent

Livestock – limit on extent of grazing land, more will come from mixed and industrialized production

Limits – Reached or Breached

ASIA: High Numbers of Poor, AFRICA: High Percentage Poor

1.7M poor, 960M undernourished people (12/2008, FAO)

Policy Concerns

• Food self-sufficiency – increase food production to meet growing population needs (need more water)

• Save water from agriculture – to meet needs of growing cities and environment (less water for ag)

• Water to fight poverty (more water)

IS THERE ENOUGH WATER?

Will there be enough water?

More People – 6.5 to 9 billion people by 2050

More calories & more meat, fish, milk

More food production – need to double grain production by 2050

More water for food – if practices don’t change, double water needs

This equation doesn’t work – something has to change

Will there be enough water?More people – 6.5 to 9 billion people by 2050

More calories & more meat, fish, milkMore food production – need to double grain production by 2050

More water for food – if practices don’t change, water needs double

Something has to change

Based on IWMI WaterSim analysis for the CA

Today

Without Water Productivity Gains,

Crop ET doubles by 2050

2050

Water Use – Today and 2050

No Water Productivity Gains

Climate Change

Some areas will be wetter, others drier, more rainfall variability, all hotter

Source: Arnell, 2003.

Water Scarcity and Climate Change

Some areas wetter, some areas drier

Source: Comprehensive Assessment of Water Management in Agriculture, 2007.

Climate Change, Water, Agriculture3 Critical Concerns

Glacial Snowmelt – Himalayas, Andes, African HighlandsRising Sea Levels - River delta systems

Mekong, Egypt’s Nile DeltaClimate Variability – across

sub-Saharan Africa

Water implications of mitigation measures?

Biofuels Afforestation

SolutionsOlivia Molden

Water Management

Major Pathways to Meet Future Food & Water Demands

• Invest in rainfed agriculture• Invest in irrigation

– Improve productivity of existing systems– Expand irrigation

• Promote trade from highly productive to less productive regions

• Manage demand, consume and waste less

Consider the Full Range of Agricultural Water Management Options

Fish, Livestock, Crops, Ecosystem Services

1. Water to Fight Poverty –what is potential?

Where are the rural poor in SSA ?

Source: FAO, 2008: Water and Rural Poverty

Poverty reduction potential of AWM solutions across livelihood zones

Source: FAO, 2008: Water and Rural Poverty

FAO - SSA 245 Million 58% are rural poor

AWM Team - SSA

279 Million 65% are poor

AWM Team - India

220 Million 90% are poor

This Project (Gates funded Ag Water Management Solutions):65M rural poor livelihoods improved in 15 years

Who could benefit from Agricultural Water Management Solutions?

2. Transform water governance

• Poverty, hunger, gender inequality, and ecosystem degradation continue - not because of technical failings but because of political and institutional failings

• Water availability has changed, but our actions have not

• No blueprints - need to craft local solutions

Transition From To

Exploiting water resources Managing Demand

New allocations Reallocating water

Who is included and excluded

Safeguarding right to water

Developing groundwater Regulating groundwater

Institutions for single sectors

Institutional frameworks able to deal with cross sectoral issues

Manage as per design

Deal with uncertainty, adaptive manage for change, data, monitoring, feedback important

Form Coalitions

• Emerging interest of private sector

• Important to trigger policy change

Water storage mitigates variability

Source: World Bank data from ICOLD

But need to re-think water storage: role of groundwater “groundwater banking” and soil moisture.

And beyond: insurance, local trade

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3. Water Storage – a safeguard against climate variability

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MAKING STORAGE “SMARTER” –storage continuum

All of the above

Planting crops

Direct,Buckets, pumps

Dam outlets,pumps, off-take towers

Natural wetlands

Reservoirs

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4. Manage Water Demand

• Reducing withdrawals mitigates – half of India’s irrigation is from groundwater requiring pumps

• Put in place innovative incentives, allocation, pricing policies to curtail water demands

• Food waste is water waste

5. Grow more food per unit of water

Increase Water ProductivityPhysical Water Productivity – more crop per drop– Reduces water needsRange shows that there is considerable scope for

improvement– Wheat 500 to 2000 liters/kg– Beef 5000 to 20000 liters/kgIPCC – crop yields in SSA could decline by 50%, butComprehensive Assessment says could more than

double with investment and management

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Number of publications related to water productivity from 1990 to 2007(The result is from Google Scholar search using fixed term “water productivity” )

Opportunities in Rainfed Agriculture• Largest opportunities to build resilience and

improve water productivity are in rainfed landscapes – low water productivity, high poverty

• Technology– water harvesting, supplemental irrigation– Field water conservation to reduce

nonproductive evaporation– Improved nutrients – Drought resistance varieties

• Expand Policies to includeupgrading rainfed systems

Asia needs to feed an extra 1.5 billion people by 2050, with food needs projected to double.

Cannot rely on rainfed alone

Asia contains 70% of the world’s irrigated area

Important to do it right for:• Climate change• Food security• Environment

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Figure 4: Standardised Gross Value of Production per unit water consumed by ETcrop

* surface water and public wells ** private wells

Large scope to improvePerformance

Water productivity variations

It won’t be easy

Adoption rates are low – water productivity not necessarily a farmer concern, markets may not be in place, need to understand political-economy of water useScale effects - Farm water productivity gains can increase basin depletion, not save water

Need to understand tradeoffs and align incentives of different actors by a variety of means (economic incentives, allocation)

Water Use – Today and 2050

Based on WaterSim analysis for the CA

Today

CA Scenario

No Water Productivity

Gains

CA Scenario: Policies for productivity gains, upgrading rainfed, revitalized irrigation, trade; reducing waste can

further reduce water needs

2050

Summary - Water Agenda

Change national perceptions Water access and productivity – high poverty

reduction potentialTransform water governance

Data, monitoring, modeling and feedback to support adaptive management

Rethink water storage – (eg groundwater banking)Manage water demandGrow more food per unit of water

Revitalize irrigation, upgrade rainfed agriculture