Download - Piloting rainwater harvesting for MUS in Dire Dawa, Ethiopia

EVERY DROP COUNTS!

Sean Patrick- 26th June 2013

Piloting Rainwater Harvesting for MUS

Dire Dawa, Ethiopia –

The lessons


Sand dams & Subsurface dams

Small dam built on seasonal riverbeds,

the raised wall captures some of the surface runoff and stored within the coarse sand deposits

Wall is built above ground,

with a spillway to allow continuous flow of water downstream


Subsurface…

SSD- impervious wall constructed on a bedrock in a trench across the valley/stream

Wall is below ground and holds flow of a natural aquifer

Capacity for the dam increased easily by adding layer of concrete wall


The Lessons• Institutional arrangements, Coordination and

Harmonization,

• Determining technology choices

• Technical design considerations, and

• MUS Field implementation considerations


Institutional, Coordination and Harmonisation

• Participation is not a straight forward concept

• High capacity demands

• Lateral and diagonal communication very crucial though difficult


Technology choice

• Local resources available

• Topography factors


Technical design considerations

• MUS: proper needs and source assessment takes time

• Projects need to be flexible to accommodate possible design alterations– Gravity water– Deep trenching


MUS Field implementation

Financial implicationsCement vs clayMachinery vs local labour

Timing matters- flash floods


Challenges for Replication

Topographical suitability (RB 25metres, hilly, soil- sand and gravel, reservoir should be based upon impermeable bedrock,

High technical requirements Not readily available in rural communities…continued need for NGO support


Justification: Benefits Vs Cost

Undeniable need of clean water in arid and semi-arid areas

Highly effective method in areas with limited rainfall and dependable infrastructure

Dam capacity expansion is cheaper; raising the walls


Justification…

Strong community involvement, old system improved

Use of locally available resources and

• Substantial offshoot benefits: re-vegetations, landscape management, new ecological zones and agri-practises


Thank You


Download - Piloting rainwater harvesting for MUS in Dire Dawa, Ethiopia

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