The Green-to-Blue Water Continuum:An approach to improve agricultural systems’

resilience to water scarcityAlain Vidal, Barbara van Koppen, David Love & David Blake

CGIAR Challenge Program on Water and Food

An old history of combined rainfed and irrigated agriculture

Since ancient times, the reality of water dependency has inspired farmers to innovate Water stored, mobilized and applied to

plants in different ways, depending on the nature of the resource available

Farmers have always dealt with the green-to-blue water continuum to extract the best productive value - not only from crops, but fish, livestock, etc

A recent history of opposed rainfed and irrigated agricultures

Since the 60s, irrigation has almost doubled - from 160 to 300 Mha. Policies keep “poor” rainfed and “rich” irrigated agricultures separated, negating the green-to-blue water continuum New irrigation farmers were historically ‘rainfed’ farmers,

if not breeders or fishers Almost half of today's irrigated surface is cultivated by

farmers whose tradition is ‘rainfed’

Green-blue water in agriculture

From Hoff & Rockström, SEI

Resilience concept

Society and nature as truly inter-connected socio-ecological systems• Non-linear dynamics• Thresholds• Alternate stable states

• PERSISTENCE absorb shocks, while maintaining structure and function

• ADAPTABILITY ability for learning, to cope with disturbance

• TRANSFORMABILITY capacity to reorganize, and create a new system

From Hoff & Rockström, SEI

Green water Blue water

Prod

uctiv

ity

Basic continuity assumption

Irrigated

Dry rainfed

Humid rainfed

Which is the right one?

Resilient Non resilientResilientNon resilient

CPWF aims to increase water productivity and to ensure more equitable use of water amongst users and the environment

The green-to-blue water continuum…

From David Molden, IWMI

…a way to reconcile opposed agricultures

Increasing water productivity and improving farmers’ livelihoods should be done along the existing green-to-blue water continuum

Could significant progress be achieved by learning from each others’ resilience?

Crossed lessons learnt from CPWF

Green water dominated systems IWRM research for mitigating drought and improving

livelihoods within the Limpopo Basin (water scarce) Improving Mekong Water Allocation in the Nam Songkhram

Basin (endangered wetland)

Blue water dominated systems Multiple Use water Systems (MUS) project in the (Andean,

Nile,) Limpopo, Ganges and Mekong basins

Lessons learnt from IWRM project

Green water is the source of runoff and percolation of blue water

Ways to improve access to green water: In-field soil water conservation techniques that increase

the rate of infiltration and percolation, e.g. mulching Micro catchment or runoff farming and supplementary ‐

irrigation to capture overland flow from areas adjacent to fields

How IWRM increases resilience

Negotiation processes

of users result in new institutions

Resilience builds upon a multi-stakeholder approach and a combination of water management interventions Household crop income raised

from US$200 to 600 per year

Green water Blue water

Prod

uctiv

ity

IWRM in water scarce Southern Africa

Resilience zone

Lessons learnt from Nam Songkhram Basin

Highly contested waterscape Floods and droughts always presented as main

obstacles to development, whereas flood pulse is main driver of wetland productivity

Multiple actors, in complex context and history Threat of ‘Water Grid’ and other mega projects ‐

hangs over future of wetlands

“paa boong paa thaam”

How is Paa Boong Paa Thaam more resilient than « development » ?

Highly diversified on-farm and off-farm green water productive uses

Household income US$1100/y

Rapid privatisation & land reform, coupled to continual pressure to build blue water control infrastructures, introduces disruptive changes Can Paa Boong Paa Thaam

survive transformation? Previous changes

proved unsustainable

Green water Blue water

Prod

uctiv

ity

Wetlands in the Mekong basin

Wetland resilience zone

Disruptive

change

Unstable zone

Lessons learnt from MUS Multiple Use water Systems

Multiple use water systems are an effective way to fight poverty by improving access to agricultural waterExperience shows that farmers use/re-use multiple (up to 9!) sources of water

livestock

door

Total area 2 ha ; ponds, paddy fields; integrated farm; and forest

Paddy field

Paddy field

Paddy field

Paddy field

Paddy field

Paddy field

Trees & fruits

Trees & fruits

12x24x5 m

Tre

es &

frui

ts Trees & fruits

Farm

Forest

Frog farm

Vegetables

Nursery

Domestic water: An ignored form of blue water

Homestead-scale MUS gives high resilience against natural- and human-made volatility Especially for the poor and for women

generates ‘more MDG per drop’ Multiple-use water ladder, with household water-derived

income ranging from US$40 to 300/year Costs for multiple-use supplies for homestead-based

production typically repaid within 3 years, from the income gained, therefore cross-subsidize domestic uses

How MUS increases resilience

Ability to use multiple sources under variousclimatic conditions or

as emergency provision, key for resilience

Community-scale MUS allows building on what communities have been doing since time immemorial

Green water Blue water

Prod

uctiv

ity

MUS - everywhere

MUS resilience zone

Single uses

unstable zone

Green water Blue water

Prod

uctiv

ity

Single uses

unstable zone

Multiple use/sources resilience

Rainfed humid

Rainfed dry

Resilience in the green-to-blue water continuum: A synthesis

Multiple water uses, techniques and

sources, together with resulting community organization do increase resilience

Neglecting the green-to-blue water continuum creates unaffordable disruptive changes

Disruptive

Change

Thank you

Alain Vidal, CPWF Directora.vidal@cgiar.org

www.waterandfood.org