ISRIC Green Water Team

Sjef Kauffman Godert van LyndenZhanguo Bai 1

Water and Sustainable Land Management• Instead of a narrow focus

on surface and ground (“blue”) water alone, more attention is needed for the green water component: water in the soil available for plant growth;

• The green water component comprises at an average 2/3 of total rainfall (Falckenmark and Rockstrom, 2006);

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• Key resource is rain water• Farmer can improve local

water balance• Upstream land management

is linked to downstream water availability

• Farmers are key and need support to make investments

• How can we support the farmers?

Starting points

Current land management practices show wasting of rain water by :

• high rates of surface runoff enhancing flash floods and erosion, and

• large losses by evaporation of water directly from bare soil (up to 60% of rainfall!)

Blue water can be better managed by good soil & water management:

• reducing runoff and erosion,• more infiltration, • less unproductive evaporation,• more water for plant growth

More water cannot be created, but:

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Better soil and water management

can also greatly increase water supply downstream and improve rural livelihoods

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Farmers know the benefits from green water management, but need incentives to cover the costs/ labour

Green Water Credits bridge the incentive gap: Compensation by water users to water providers for specified water management services

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Targets/Potential benefits

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Who and where are the key players?

4 Work Domains

1.Biophysical analysis

2.Socio-economic study

3. Institutional inventory

4.Financial Mechanism

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Estimated increase in hydro-power from green water management (50% cut in erosion/siltation)

Masinga gfedcbKindaruma gfedcbKiambere gfedcbKamburu gfedcbGitaru gfedcb

Hydropower GenerationScenario: upland_management, All months

1989 1992 1995 1998 2001 2004 2007 2010 2013 2016 2019 2022 2025 2028

Thou

sand

Gig

ajou

le

200

180

160

140

120

100

80

60

40

20

0

100 000 GJ =

51 000 barrels oil

= $ 5.8 million

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Green Water Credits

Phase I Proof-of-Concept/Business Case

Phase II Design and capacity building

Phase III Implementation

(Morocco)

(Kenya)

(Algeria, China?, Ethiopia??, Burundi??)

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Started 2006

Currently implemented in

•Kenya, Upper Tana Basin (Phase II, till Sept. 2011: Project Design)

•Morocco: Sebou Basin (Phase I, till Sept. 2011: Proof of Concept)

•Algeria (Project preparation)

•China, (Proposal)

Results

Upper Tana, Kenya

Sebou Basin, Morocco

WOCAT in GWC

Potentially relevant Green Water technologies for altitudes from 500-2000 m

(Source : WOCAT database)

Quest Id SWC Technology Name LGP

Measurements/ Estimates PlantType

Production

Prod Diff%

Soil Loss (t/ha)

Soil LossDiff

SoilLoss Diff%

Runoff (% of rainfall)

Runoff Diff

Runoff Diff%

CHN21 Orchard Interplanted with Bahia Grass (Paspalum notatum)

90 estimates artificial forest   3 21.3 88% 35 35 50%

CHN40 Zero Tillage 180 measurements wheat/corn 13 30% 3 22 88% 5 25 83%

CHN41 Subsoiling 240 measurements wheat /corn 13 30% 5 45 90% 5 25 83%

CHN42 Auto-Flowing Slurry Dam 165 measurements crop 2.6 420% 20.6 59.4 74% 35 8 19%

CHN43 Pits 160 measurements trees   3.08 10.34 77% 2 8 80%

CHN45 Terrace 160 measurements crop 2.7 108% 58 122 68% 4 6 60%

CHN47 Check Dam 180 estimates   3.5   110 70 39% 30 18 38%

CHN49 Caragana Korshinskii Planting----a kind of SWC vegetative technology

160 estimates Stipa bungeana

3.375   75 95 56% 2 8 80%

ETH01 Trashlines 90 estimates mixed cereals & pulses, cotton

1.3   10 90 90% 25 45 64%

ETH04 Hillside Terracing 90 measurements grass/bush/tree

13   30     40    

ETH11 Multiple Cropping 90 estimates Sorghum 0.9 50%     10 40 80%

KEN05 Fanya Juu Terrace 90 estimates maize 1.5 50% 2 9 82% 20 30 60%

KEN10 Road runoff management - Nyeri 120 estimates   1.35 25% 15 10 40% 20 30 60%

KEN11 Road runoff system - Mwingi 105 estimates all 1.5   2 10 83% 10 70 88%

KEN15 double dug beds - Busia experience 120 measurements maize 2 150%     5 10 67%

KEN16 Grevillea tree planting as an agroforestry intervention

100 estimates coffee 7.5 0% 3.5 1.5 30% 35 5 13%

KEN22 Water Harvesting and Enlarged Structures

90 estimates maize 1.2 100% 0.8 7.2 90% 7 38 84%

KEN22 Water Harvesting and Enlarged Structures

90 estimates beans 0.6   0.8     7    

KEN22 Water Harvesting and Enlarged Structures

90 estimates sugarcane 5   0.8     7    

KEN22 Water Harvesting and Enlarged Structures

90 estimates banana 3   0.8 7.2 90% 7 38 84%

KEN23 Riverbed reclamation & silt trapping for sugarcane

75 estimates sugarcane 5   5 7 58% 20 40 67%

KEN24 Gully Reclamation 60 estimates banana 4   0.6 609.4 100% 10 50 83%

KEN24 Gully Reclamation 60 estimates pawpaw 8   0.6     10    

KEN24 Gully Reclamation 60 estimates grass   0.6     10    

KEN25 Pasture Mangt. through Removal of comiphora

70 estimates comiphora   1 2 67% 8 12 60%

KEN26 Water Table Management 70 estimates sugarcane 6 100% 0.5 1 67% 4 4 50%

KEN27 Gully blocking by stone checks 120 estimates fruit trees   0.5 5 91% 10 40 80%

KEN30 Conservation Tillage through ripping 120 estimates wheat 2.7 80% 0   20 30 60%

NEP11 Landslip and stream bank stabilisation 120 estimates Alnus, L. cardamom, bamboo

5   10 190 95% 35 45 56%

Quest Id SWC Technology Name LGP

Measurements/ Estimates PlantType

Production

Prod Diff%

Soil Loss (t/ha)

Soil LossDiff

SoilLoss Diff%

Runoff (% of rainfall)

Runoff Diff

Runoff Diff%

Examples from WOCAT database (> 350 technologies worldwide)

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CONCLUSIONS

• GWC is a financial facility to support farmers in soil and water conservation activities:

1. For initial investments (short term)

2. For maintenance investments (long term) in appropriate green water management

3. Where downstream water users compensate farmers upstream for the benefits derived from appropriate soil and water management

More information...

www.isric.org www.greenwatercredits.netwww.wocat.net

Godert.vanlynden@wur.nlSjef.Kauffman@wur.nlZhanguo.Bai@wur.nl