Presentation sharing the lessons on piloting rain water harvesting for MUS in Dire Dawa, Ethiopia. By Sean Patrick, RAIN Foundation. Presentation during the Seminar on Multiple Use Water Services in the context of Dutch policy and practice. Wednesday 26 June 2013, The Hague, The Netherlands.

1. EVERY DROP COUNTS!
Sean Patrick- 26th June
2013

2. Piloting Rainwater Harvesting for MUS
Dire Dawa, Ethiopia –
The lessons
Sean Patrick- 26th June
2013

3. 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
Sean Patrick- 26th June
2013

4. 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
Sean Patrick- 26th June
2013

5. The Lessons
• Institutional arrangements, Coordination and
Harmonization,
• Determining technology choices
• Technical design considerations, and
• MUS Field implementation considerations
Sean Patrick- 26th June
2013

6. Institutional, Coordination and
Harmonisation
• Participation is not a straight forward
concept
• High capacity demands
• Lateral and diagonal communication very
crucial though difficult
Sean Patrick- 26th June
2013

7. Technology choice
• Local resources available
• Topography factors
Sean Patrick- 26th June
2013

8. 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
Sean Patrick- 26th June
2013

9. MUS Field implementation
Financial implications
Cement vs clay
Machinery vs local labour
Timing matters- flash floods
Sean Patrick- 26th June
2013

10. 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
Sean Patrick- 26th June
2013

11. 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
Sean Patrick- 26th June
2013

12. 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
Sean Patrick- 26th June
2013

13. Thank You
Sean Patrick- 26th June
2013