WASH Cluster – Drainage
DR5
Session Plan
DR5- Drainage Design
Example Timetable
½ day 3.5 hours total
DR1Introduction
Reasons for
Drainage
DR2Strategy
10 mins
DR3- Site
Conditions
30 mins
30 mins
DR4- Drainage
Solutions
Exercise and
Summary
DR5Drainage
design
50 mins
50 mins
DR6- WASH
Cluster:
Lessons Learnt
10 mins
DR7- Key
points
Summary
10 mins
Session-at-a-Glance
Session Activities
Introduction
Approx.
Time
Instructional Activity
5 mins
Putting into practice knowledge from
previous session to carry out Detailed
Drainage Design
20 mins
Group work using case studies
Feedback findings of case study to the
group on drainage strategy, problems
and solutions
20 mins
Presentation/ Group Feedback
Sum up main points
5 mins
Total time
Trainer Feedback
50 minutes
Session Aims
 Practice selecting and designing a drainage solution for a real case example
Session Objectives
At the end of the session participants should be able to:
 Make an overall drainage plan for a real site
 Explain the problems associated with certain scenarios
 Produce a detailed design for drainage components
Session Materials

Computer and projector

Flip chart paper and pens

This Session Plan,

WASH DR Powerpoint

Printout of Powerpoint

Handouts for participants
-
Two group scenarios
Key Messages

Real Situations are complex and each is unique

Drainage is often not an immediate priority in emergency interventions

By analysing the site location, drainage problems can be anticipated beforehand

Drainage will be needed at water sources and water usage points
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WASH Cluster – Drainage
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DR5
Mobilisation of residents can save a lot of work
Facilitator Guidance
This session is about putting together the learning for a scenario based on real drainage problems
in emergency settings. There are two contrasting scenarios one based on a rapid refugee influx in a
mountainous region in the Balkans, with an Eastern European continental climate (as described hot
dry summers, freezing snowy and wet winters), a non suitable site in terms of topography (very
steep), complex issues of contaminating the groundwater from latrines and a population mixed of
rural and urban dwellers with different expectations and customs. The refugee population included
all groups of people, participants should consider which groups would be more vulnerable under the
similar living conditions.
The second scenario is based on the recent earthquake in the Caribbean, a natural disaster on top
of a country with a historical record of poverty and political turmoil, in this case people were
internally displaced (although displaced not very far, close to their destroyed homes), very self
reliant but needing extra assistance from the international community. A hot and humid climate
with expectation of further natural disasters with an intense rainy season and hurricane season to
follow shortly. Extremely crowded conditions in self made shelters means providing additional
services difficult due to lack of space and vehicular access.
The timing depends on the group size and how quickly they work/ present, knowledge of English
etc, suggest being flexible. Some time can be taken from the next session if needed, as this is a
useful session for exploring the complexities of the real situations.
Session Plan
There are two case studies, continue working with the same groups (as is
a short module and provides consistency), 50 minutes total, make a
quick introduction and allow reading time for the groups. Designate one
scenario to each group (probably best not to allow a debate on who gets
which scenario), then the time is their own provide direction if needed.
Handout different scenarios to each group.
2 different case studies, based on real emergency examples, dealing with
common drainage problems (identified within sphere)
Allow 20 minutes for the work and then group presentations for 20
minutes, if the group is large use one group presenting and then another
group that worked on the same scenario provides questions and
contrasts with their own conclusions, trainer can add further information
from the notes and their experience/knowledge as required.
•
SCENARIO 1:
A site has been selected for 40,000 refugees who have crossed a mountainous border in
Eastern Europe. The refugees are fleeing ethnic persecution and although many normally
have a reasonable standard of living in cities have had to make long arduous walks across
the mountains, carrying all their possessions. Some are from rural areas and carry stoves
and some food.
•
The area has cold (-20o C) and snowy winters are followed by spring rains and hot
summers. It is April and the camp is being prepared for the imminent arrival of the refugees
in a few days.
•
The site is on the edge of a wide river valley, a large river flows through the valley floor, the
valley is mainly used for farming, on the edge of the river plain is an existing village which
uses shallow wells as a water supply. The proposed camp lies just above the village, at the
foot of a steep mountain chain, the camp is situated about 40m in height above the river,
the awesome rocks of the mountain rise above a steeply sloping naturally wooded area
which is above the camp.
Session Plan – DR5
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WASH Cluster – Drainage
DR5
•
The soil in the valley is rich alluvium clay, where the camp is it is rocky, as the site was
formerly a municipal refuse (garbage) dump for building and non hazardous materials, it is
recently been used for sheep herding. Under the surface is fissured and fractured limestone
with dry ephemeral (sometimes flowing) stream valley on either side of the site.
•
Assume all other standard camp services are met by other agencies, apart from fuel for
cooking which is being discussed. The camp is being planned with a typical services for a
high profile emergency such as road systems, hospitals, schools, kitchens, warehouse,
tents, it is steep at 1:10 (10%) slope. Agencies can be supported by International forces
with extensive range of vehicles, machines and gravel.
•
Make a preliminary drainage strategy, make reasonable assumptions if the information is
not to hand, be prepared to present your plan and assumptions. What are the most likely
drainage problems, what do you propose as the solutions?
TRAINERS NOTES
This scenario is based on a real situation. The dangers of drainage from latrines were polluting
the existing village water supply as it lay just below the camp and relied on shallow wells. Also
The fractured limestone could transmit wastewater quickly. Latrines were therefore using sealed
tanks which were pumped out.
Water usage was extremely high for an ex urban population not used to water scarcity, so there
was a high water wastage.
Soakaways were built at all washpoints, tapstands, body and clothes washing areas, a trial pit
of 2m x 2m x 2m failed, so with plentiful supply of gravel large 3m x 3m x 3m pits were used,
the water table near the mountains was very deep (+50m).
Heavy rains caused empty latrine tanks to pop out (buoyancy).
Lack of fuel, meant trees above the camp were cut for stove fuel by the refugees, added to little
vegetative cover due to compaction of 40,000 people and use of heavy machines meant runoff
from heavy rains was fast and furious. Roads were laid to grid plan, not on contour and
although a large gravel filled open channel was laid directly down through the camp, it speeded
up the flow causing tents to be washed away in a flash flood, causing misery for those affected
and soil and gravel were transported down to the village, blocking the main road.
Further solutions included a protection bund at the top of the camp, diverting the water from
the mountain worked well, swales (low earth bunds) and roads laid on contour, prevented
runoff water from gaining speed and allowed it to infiltrate slowly back into the soil- these were
part of the remedial works for the camp rehabilitation.

SCENARIO 2:
Following a devastating earthquake in the Caribbean early in the year. Numbers of
casualties and those affected were estimated to be 1.2m families homeless and 230,000
deaths. The worst affected areas included the capital itself, A revised Emergency Appeal
was issued to assist 80,000 families living in self settled camps within the capital.

12,000 people have self settled a piece of wasteland behind a car dealership. They have
organised themselves with an elected committee and zone representatives.

The site is very compact with self made shelters squashed together with minimal free space.

Pit Latrines have been constructed revealing a variety of soil profiles; broken down garbage,
mixed loam, sand and clay. The latrine on the highest point encountered water at 1m deep,
but this appears to be a localised problem or a burst water main.

The climate is exceptionally hot and humid, dust still lingers in the air after the earthquake
with danger of aftershocks, an intense rainy season is expected shortly to arrive in May, in
late summer the region is often hit by severe hurricanes.

An existing surface water drainage pipe (buried, 1m diameter) crosses the site, some
manholes have open grates leading to this pipe. The vast piles of garbage lying in the site
are being regularly cleaned away.
Session Plan – DR5
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WASH Cluster – Drainage
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DR5
Make a preliminary drainage strategy, make reasonable assumptions if the information is
not to hand, be prepared to present your plan and assumptions. What are the most likely
drainage problems, what do you propose as the solutions?
TRAINERS NOTES
Based on the response to the 2010 Haiti Earthquake. Existing committee meant work was
easier to carry out with the community. Pit latrines needed to have raised edges to prevent
water ingress. Heavy rains when they came necessitated a drainage system of shallow dug
ditches. Tool distribution through the committee allowed people to protect their own shelters
which were just plastic tarps from water ingress. Small digger provided longer ditches in the
streets, quantities of gravel were trucked in to stop streets becoming very muddy. Water
from new bathing areas was channelled into grates above existing sewer and sewer cleaned
from garbage to prevent blockage.
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