SOCIAL AND ENVIRONMENTAL BENEFITS OF SPATE IRRIGATION DEVELOPMENT

1.5

Social benefits

In many areas spate flows are the only sourceof water – so livelihoods depends on the abilityto control the floods and store the water

Livelihood impacts and social benefits

Social benefits of spate irrigationGeneral:

• Poverty alleviation• Improvement of food security• Improvement of local economy• Creation of labour opportunities• Reduction in seasonal migration

Specific:• Domestic water for human beings• Drinking water for livestock• Forest and rangeland• Source of building material

]Domestic water

Domestic water supply – especially wheregroundwater is not available or useable (saline):Wells in ephemeral riverbeds

Livelihood impacts :Water supply for livestock

Zizyphus:The Miracle Tree

Source of woodWood for implements, construction, timber, fruits

In several areas part of the spate flows used for irrigating forest or

rangeland

Improving social benefits:domestic water supply

• Improved wells• Subsurface dams• Sand dams• Plastic lined ponds

Improved wells

Subsurface dams

Constructing subsurface dam

Subsurface dam “at work”

Plastic lined ponds and filters

Source of building material

Mud

Sand

Environmental impacts

Environmental benefits of spate irrigation

• “Fixes” the area and avoids erosion • Maintains large vegetative

biodiversity• Improved structures may reduce

cutting of trees/shrubs for traditional structures

Maintaining the spate system in area prevents excessive gully-ing, erosion, changes in river morphology,wind erosion and the return of the area to desert situation

Alternatively, the destruction of a downstream riverain forest in thisarea (Yandafero, Ethiopia) caused the river to change to a lower courseand cause a massive decline in the river bed levels in this area, making it almost impossible to divert water from the river

The vegative biodiversity in spate irrigation system is often very large,as seeds are transported over a large area by the floods and ‘dumped’ and left to germinate in the moist soil of the spate systems

Traditional brushwood structures put a huge demand on localvegetation in usually fragile environment – replacing them with improved structures reduces deforestation