WASH Cluster – Ground Water Pumping
GWP4
Session Plan
GWP4 – Water Distribution
Timetable
GWP0 - Opening &
Introduction
GWP1 – Handpumps
30 mins
GWP2 – Motorised
Pumps
1 hour
GWP3 – Assessment
of pumping method
1 hour
GWP4-Water
Distribution
1 hour 35 mins
40mins
Session-at-a-Glance
Session Activities
Approx.
Time
Considerations for water source protection
15 mins
(slides 1-5)
Instructional Activity
Power point and plenary
discussion
Soakpit design (slide 6)
5mins
Participants sketch out design
Discussion about the importance of
chlorination (slide 7)
5mins
Discussion and optional
exercise
Water demand considerations
5mins
Plenary discussion
5mins
Powerpoint
(slides 8-9)
Distribution systems
Considerations when installing public
standposts
Total time
10mins
Plenary discussion
40 mins
Session Aims
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To highlight that a pump can never be looked at in isolation but needs to fit into an overall
system of distribution consisting of a water source (borehole or well), protection of water
source and the distribution to the taps.
Session Objectives
By the
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end of the session, participants will be able to:
Describe the components involved in protecting a water source.
List some of the risks of a poorly protected water source
Explain how seasonal fluctuations affect demand and how this can be attenuated
Discuss the key considerations for public stand posts.
Session Materials

Computer and projector

Chlorination handout from W4
Key Messages
 The procurement is only one part of the process the pumps need to be installed on the well.
Good quality workmanship is essential
 The water source needs to be protected
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Measures need to be taken to ensure that the water quality remains safe for a long term
(indefinitely)
There are implications for maintenance when installing public tapstands
By the end of
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the session, participants will understand in broad terms:
The aspects or water demand fluctuation
The need to have storage facilities (reservoirs, tanks, etc)
The types of distribution systems used
Connections and tap stands
Facilitator Guidance
Session plan
Introduce the session by talking about the benefits of safe drinking
water - combat water borne diseases, improves community health,
positive influence on the general well being, economic status
Q: Ask participants what the main considerations are when protecting
a water source.
Discuss benefits of choosing a well drained site.
Talk about contamination risk from humans and animals
A: The safety measures are as follows:
 The well should be in an elevated place, so that during the
rainy season the water will run away from it, rather than into
it.
 It should be at least 30 meters away from a latrine and uphill
of the latrine (Take it as a general rule. The geology of the
surrounding soil/rock influences the germ-freeing capacity.
The distance might be far too safe for sands or not enough for
limestone)
 It should be at least 30 meters away from a cattle kraal, and
uphill of the kraal.
 It should be well away from any depressed area in the ground,
such as hollows that are used for rubbish tipping, hollows that
are used for brick making or any other areas where water
might collect.
Q:Ask participants what risks are caused by a badly drained borehole.
A:
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health risks of dirty stagnant water. Parasite and/or disease
carriers(such as guinea worms).
possible benefits from an improved water supply will be lost if
poor hygiene conditions
contamination of the aquifer through the infiltration of dirty
water back into the aquifer
Discuss importance of constructing a platform (or slab) at the
wellhead the surface, the slab will help to prevent the contamination.
Important points to mention;
 Consult with community
 Construct after soil around well settles
 The slab should be made from reinforced concrete of good
quality. It must be large enough to collect spill water, which
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then can run away thorough the drainage channel.
All surfaces must slope towards the drainage channel and
edges of the slab must be raised.
The slab should be well reinforced with steel wire, to prevent
cracking (dirty water is passing easily through cracks in the
platform and can contaminate the well beneath).
Run off should be to soak away or vegetable patch
Ask participants what is necessary to ensure platform cures properly.
Mention points on the slide
Therefore it’s advisable to make partitions of clay or other material,
so that water is blocked from draining.
Discuss other ways to protect water source and collect examples that
participants have tried.
Ask participants what are the advantages of fencing?
- Defines well area
- keeps animals away from the borehole.
Discuss disadvantages e.g upkeep and repair but also living hedge as
an alternative
Whatever type of fencing is used, it is important that access by the
well users is guaranteed.
Ask participants to sketch what they think a soakpit should look like.
Compare drawings then show the slide.
Q: Ask participants who has carried out chlorination and why is it
important?
A: Kills disease carrying organisms found in the water Therefore it is
recommended to disinfect the well shortly before the installation of
the handpump takes place.
Explain the theory of chlorination.
( The calculations for 1% solution might make a good short exercise.
Refer to the Water module session W4 Handout Practical chlorination)
Write up the formula on a flipchart.
Total head = static head + friction loss+ secondary losses
And explain it using the diagram on slide.
The friction head loss for a given flow rate can be calculated for any
chosen pipe diameter. Smaller pipes create higher losses than bigger
pipes because the water speed is greater. The pump has to be chosen
that is able to produce the required flow and pressure.
Q:Ask participants what affects water demand
A: Seasons, climate, harvest pattern, cultural or religious occasions
etc.
The maximum daily demand is usually estimated by adding 10 to
30% to the average daily water demand. This gives a “peak factor”
(k1) for the daily water demand of 1.1 to 1.3.
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The hourly variation in the water demand during the day is frequently
much greater. Generally, two peak periods can be observed, one in
the morning and one late afternoon (see Diagram).
For a particular distribution area this factor depends on the size and
character of the community served. The hourly peak factor tends to
be high for small rural villages; it is usually less for larger
communities and small towns.
Where roof tanks or other water storage vessels are common, the
hourly peak factor will be further reduced. Usually the factor K2 is
chosen in the 1.5 to 2 range.
A water distribution system typically is designed to cater for the
maximum hourly demand. This peak hour demand may be computed
as k1 x k2 x average hourly demand.
Q: Ask participants the purpose of reservoirs.
A: To balance the (constant) supply rate from the water source or
treatment plant with the fluctuating water demand in the distribution
area. The storage volume should be large enough to accommodate
the cumulative difference between water supply and demand.
Storage volume of service reservoir = 20 to 40% x peak day water
demand
Discuss requirements of storage reservoir.
Q: Ask when would you use water tower.
A: In flat areas where ground reservoirs not possible water towers
and elevated tanks have relatively small volumes because they are
much more costly to construct than a ground reservoir.
Ground reservoirs of some size are normally of reinforced concrete;
small ones can be made of mass concrete or brick masonry.
Elevated reservoirs are of steel, reinforced concrete or brickwork on
concrete columns. Steel- or Plastic tanks are mostly placed on a steel
or wooden support framework.
Describe the two distribution systems. Explain the importance of
maintaining sufficient distribution pressure to protect it against
contamination by the ingress of polluted seepage water. 6m is
adequate for small community supplies.
Branched system
Branched systems are only used for small-capacity community
supplies, delivering the water mostly through public standpipes and
possibly few house connections.
Q: what at the advantages of branched systems?
A: straight-forward design & direction of the water flow in all pipes
and the flow rate easy to calculate
Looped System
Looped network more common for larger distribution systems grids.
Q: What are the advantages & disadvantages of looped systems?
A: More complicated to design, more costly but more stable water
pressure for users in densely populated areas and small sections of
the system can be isolated for repairs without affecting the rest of it.
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Public Stand post
Public stand posts are the best option for water distribution at
minimum cost to a large number of people who cannot afford the
much higher costs of house connections.
Q: Discuss the advantages and disadvantages of public standposts
versus household connections. Participants can form groups and are
given specific topics to discuss and report back on.
- effect of usage
- ease of connection
- Maintenance of public systems
- Capital costs
- Waste water disposal cost
- Distance to user (refer to SPHERE)
- Discharge rates
- Number of users per standpost
- Pressure at standpost
- Wastage
- Contamination on transport, water containers
- Use of water kiosks for payment collection
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