A framework for water drainage and retention interventions within the Za'atari Refugee Camp in Jordan.

1. Storm water drainage and
retention framework for
Za’atari Refugee camp
Cedrick Gijsbertsen

2. • Problem statement
• Principles of the framework
• Building a Model
• Results / possible solutions
• Discussion
Content of presentation

3. Water at Za’atari
Refugee Camp
Two constraints
Water
surplus
Water
shortage
Problem statement

4. Storm events
(floods)
Draught – water shortage
Irregular rainfall
Intensity causes floods by surface runoff
(around 150 mm/year)
Problem statement

5. Alignment
districts and
roads not in line
with
demography
and landscape
Problem statement
No infiltration of
rainwater into
the soil.
Rainwater turns
into runoff.

6. Floods at the camp
Problem statement

7. Principles of the framework
• Find solutions that are:
• robust,
• simple,
• easy to understand/apply,
• affordable
• Find solutions based on the current
(urban) status quo
• Involve inhabitants and create
ownership

8. Storm water system is not simple
• for simple solutions a thorough analysis
was needed (one solution leads often to a
new problem)
• reports of earlier studies
• specific data was needed to identify
(future) constraints (DEM from RJGC )
• adjustment and checks of the accuracy of
surface elevation and current interventions
Principles of the framework

9. Building a model
• Identify constraints
• Provide insight in amounts and scale
• Design solution and visualise effects
• There’s no “one-size-fits-all solution”…
specific locations need customized solutions

10. Roads are constructed
on the terrain (slightly
elevated).
Acting as a barrier for
water flow
Building a model: Constraints

11. Constraint: Capacity of culverts
too small for the amount of runoffsufficient for amount of runoff

12. 1 single rainfall event on this area
results in 18.000 m3 of water
That’s 7 Olympic sized swimming pools!
Interventions on larger scale needed

13. Drainage frame work
1. Improve capacity peak flow
2. Increase drainage of camp
3. Slow down, store and guide runoff
4. Facilitate and stimulate inhabitants

14. FASE 1
Main
drainage
structure
Fast drainage of the peak flow and storage in structure
Dimensions flexible based on available space (minimal 3m x 1m)
Densely populated, with
minimum “public space”

15. PHASE
2A
Secondary
drainage
structures
Guide surface runoff to main structure and storage
Facilitate inhabitants to connect to the system and improve drainage of
individual plots

16. PHASE
2A
Facilitate?
Responsibility and ownership for water on own plot
Inhabitants: Store water and connect to drainage structure
(manual labour)
UNHCR: Provide facilities (drainage structures) to connect to

17. Combine flood protection with storage
Slow down and decrease runoff water to areas with flood risk
Store water in areas without flood risk (harvest)
Provide water for vegetation and future runoff control

18. PHASE
2B
Collect
and store
Rainwater harvesting (collect & store) at locations without flooding
Use stored water for vegetation and more robust future water system

19. Collect & store
rainwater
Example
If all cabins can
collect and store
1,5 m3 of
rainwater,
floods can
decrease with
30%
Collect & store
Rooftop harvesting
Collect & store
In public area
Collect & store
In public area

21. Heavy rains for 30 minutes

22. 1 hour after storm event
40% decrease of storm water on surface

23. Interventions upstream
Increase capacity of outflow (culverts)
downstream
For a shorter time
Less
water on
surface
UPSTREAM
DOWNSTREAM

24. Solution guidelines (summary)
MAIN DRAINAGE STRUCTURE
Increase capacity peak flow
Guide first flush out of the camp
Increase capacity culverts downstream
SECONDARY DRAINAGE STRUCTURES
Storage and guiding to main structure
Improve total drainage
Stimulate and facilitate water ownership on plots
RAINWATER HARVESTING (RWH)
Storage and guiding to main structure
Stored water for vegetation and runoff control
Stimulate RWH on plots
EXPAND OPPORTUNITIES RWH
Expand storage in drainage structures
Create awareness necessity green space

25. Discussion