piloting rainwater harvesting for mus in dire dawa, ethiopia
DESCRIPTION
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.TRANSCRIPT
EVERY DROP COUNTS!
Sean Patrick- 26th June 2013
Piloting Rainwater Harvesting for MUS
Dire Dawa, Ethiopia –
The lessons
Sean Patrick- 26th June 2013
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
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
The Lessons• Institutional arrangements, Coordination and
Harmonization,
• Determining technology choices
• Technical design considerations, and
• MUS Field implementation considerations
Sean Patrick- 26th June 2013
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
Technology choice
• Local resources available
• Topography factors
Sean Patrick- 26th June 2013
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
MUS Field implementation
Financial implicationsCement vs clayMachinery vs local labour
Timing matters- flash floods
Sean Patrick- 26th June 2013
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
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
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
Thank You
Sean Patrick- 26th June 2013