The importance of

water storage in the

homestead

Peter Morgan 2016

2

Introduction

In this part of the world, the way and regularity in which we obtain our water for domestic and other

uses varies considerably. Unlike most developed countries whose water is regularly delivered through

a series of house taps, this is not the case in countries like Zimbabwe. If water is delivered from a

municipal source it may be intermittent. And the quality of such water may be questionable. Large

numbers of families living in the urban centres have resorted to digging their own wells or drilling

their own boreholes to obtain water. Within the suburbs there is a great variation in the depth of the

underground water table. In some suburbs water can be found less than 10m down – in others 50+m

down. Also there is seasonal variation in the levels of ground water and the water level itself very

much depends on the amount of rainfall within the season. Rainfall patterns are also varying as they

have done for many decades. There are years when the rainfall is above average, and others when the

total is below average. The level of water in the ground greatly depends on the amount of rainfall.

Such changes are normal parts of the local weather cycles found in this part of the world. However

there are longer term cycles which also influence climate, when the Earth may warm or may cool.

Ocean currents also affect climate, like the El Niño-Southern Oscillation (ENSO), a cyclical pattern

involving the relationship between the temperature of the Eastern equatorial Pacific Ocean and global

weather patterns world-wide. The El Niño cycle is currently causing a below average rain fall seasons

in Zimbabwe. Thus all forms of water supply may be under the influence of their periodic own cycles,

when the supply may be quite adequate for a period, followed by another period when the supply may

be marginal or inadequate. This work briefly describes ways of buffering the periods of inadequacy by

building storage tanks or reservoirs within the homestead and then taking steps to ensure the water is

safe for use and drinking. The sources of water varying considerably from household to household.

They may include a piped supply, a ground water supply, a rainwater supply or even a bulk delivery

water supply. I exclude here water sold in bottles. In our own case we rely on a ground water supply

and also a rain water supply.

If the supply is intermittent, then a system of safe storage and delivery can help enormously. Most

conveniently this can be made in the form of a sealed tank or series if tanks which can be placed above

ground, at ground level or even below ground level. The water thus held can be delivered through a

tap, a mechanical pump or even a hand pump. If the tank is built above ground level, then a tap can be

used for delivery. But care is required with taps fitted to tanks holding precious water – they must be

turned off when water is not required, because the tank supply is limited and stored water may run out

overnight. There is also a potential problem in terms of water quality when water from different

sources is mixed (such as from a roof catchment and ground water source). Rainwater taken from a

roof will be unfit for human consumption unless it is treated, and the same will be true for poorly

protected wells. Well-sited borehole water will be infinitely safer to drink. Municipal water quality has

been deemed unsafe in some circles or at least below international requirements. But for many there is

no choice.

Purification of drinking water in the kitchen can reduce health risks considerably. Personal hygiene,

hand washing, and the careful handling of food also come into the picture. Also, if water is scarce, the

careful use of the water by reducing the flush of toilets and the amount of water used for bathing can

extend the life of stored water. There are several ways of washing the hands which use water

economically. It’s an interesting story, but also an important one and may even be a critical one.

I describe below systems which have been in use for some time in our own homestead and these have

assisted us greatly in storing, delivering, purifying and saving water in our homestead in Harare. It is

related to the twin concepts of self-supply and do-it-yourself.

Peter Morgan

Harare

March.2016

3

Water storage tanks

Many types of tanks are commercially available in the towns and cities. Nowadays the green plastic

tanks are popular and seem to be the most common. They vary in capacity from 500litres to 5000litres.

Also on a smaller scale, 25litres plastic containers can be purchased for about $4.00 in local stores.

But tanks both above and below ground can also be built with concrete, bricks and mortar by a builder.

Photos of brick built tanks

A suitably sized hole is dug and a strong concrete base is laid on the bottom. Then a brick wall is built up. Above

ground the bricks can be corbelled so the top has a smaller diameter.

The inner walls of the tank are carefully mortared with a strong Portland cement pit sand mix. A step is built up to

the top of the tank and a concrete cover is made with a hole for the pump and a hole for the water inlet.

The “headworks” are then built in bricks and mortar with a concrete mount for the chosen pump and a concrete

mount for the water inlet. A rim of bricks is built around the concrete well slab. A water run-off channel is also

built which leads waste water to a seepage area

Left: Finally a suitable pump is fitted – in this case a high delivery hand-made Blair Pump. Middle and right: A

variety of brick built tanks can be built above ground level. These can be fed from several sources: underground,

rain, piped and even bulk delivered water.

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Sources of water

Water derived from boreholes can be directly pumped into the tank through piping. It can then be

withdrawn at will. This also applies to other sources of water if the supply is intermittent. Rainwater

derived from plastic “rain catchers” has a higher quality than rain water collected from roofs. The

quality of water derived from wells will also vary, depending on several factors including the extent of

headworks protection, distance from a potential source of contamination and also season.

Rainwater harvesting

Water being delivered from a plastic “rain catcher” to two brick built water storage tanks. The

larger tank, left, was mostly built below ground (see earlier photos) and fitted with a high

delivery hand pump. The tank shown on the right photo was built above ground and fitted with

a tap. The “rain catcher” was made with solar resistant plastic sheet and is partable. It can

collect and deliver high quality water if suitably sited and cared for. The left photo shows 25mm

plastic pipes leading from the plastic “rain catcher” and also from two sections of roof

catchment.

The great value of building larger brick tanks, which are well sealed from the ingress of foreign matter

and even animal life like lizards and even ants, is that particles in the water can settle out to the

bottom. The concept of settlement of particles held in water is valuable, since even this simple process

can improve the quality of water by improving clarity and also reducing any bacterial contaminants

carried in the body of the water by sedimentation. Bacteria can stick to sediments, so the more

sediments fall to the bottom, the better. Improving water clarity also assists further purification using

ceramic candle filters placed in the kitchen, especially for the purpose of providing quality water for

drinking.

On a much smaller scale rainwater can be collected from small plastic collectors and stored in

25litre containers.

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Delivering stored water by hand

Once the water from whatever source is in the tank, then it must be allowed to settle and then can be

pumped out in the most convenient way. This can be performed by a range of small electric pumps,

but in this case I have used a high delivery simple hand pump based on the Blair Pump principle. Hand

pumps like this are quite simple to make and low cost. They may only need to raise water about 2 or

3m, but can deliver water fast into buckets which can then be taken into the kitchen for household use.

It is wise to purify the water further in the kitchen with a ceramic candle filter if it is used for drinking.

A home-made high delivery Blair Pump just before fitting on to the water tank. The Blair Pump

consists of two pipes with a non- return valve attached to the end of each pipe.

The outer pipe which acts as a cylinder has a brass non return valve attached to its base. The

inner (pushrod pipe) also has a similar non return valve attached to its base encased in an

expanded section which acts as a piston.

Left: The lower end of the pump with foot valve assembly attached and piston attached to push

rod. (A manual written by Aquamor describes how this pump can be built)

When the tee shaped handle at the top of the pushrod is pushed down, water is discharged

through the pipe into the bucket.

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Water quality and purification

If water is derived from a borehole, it may be fit for drinking without further treatment. This may also

be true for water collected from a well maintained plastic “rain catcher.” However if water is to be

used for drinking it is very wise to purify it further, from whatever the source of water. If the water in

the tank is mixed from a variety of sources, it is essential to purify it further. The simplest and most

effective method is to use a ceramic “candle filter” unit. Because the water in the tank should have

settled and the foot valve of the pump is raised from the base of the tank by about 30cm, the pumped

water should have clarified well and be very suitable for use in a ceramic “candle filter” water purifier.

A method of making a home-made candle filter using a commercially made “candle” is described in

another Aquamor publication. Complete units can be purchased commercially. They are an excellent

asset to any home. Ceramic candle filters are designed to filter out harmful bacteria in water, but they

can clog up if the water to be filtered contains too much sediment. Thus the clarifying effects of

holding the water in a tank can help the functioning of the candle filter purifier immensely.

Ceramic candle water filter units

Left photo: two Ceramic candle filter units for water purification. The one on the left is home-made from

two 20li buckets and a commercially made ceramic candle filter. The light yellow ceramic filter unit is on

the right of the photo. Middle photo. The ceramic candle filter itself. Right photo: the ceramic candle

filter threaded extension fitted through the base of the upper bucket. Clarified but untreated water is

placed in the upper bucket and slowly filters through the ceramic candle filter into the lower bucket

which is fitted with a tap. Water for drinking is taken from the tap.

Candle filter maintenance

Eventally the candle filter will deliver less water as the outer surface of the filter becomes covered

with silt and the tiny poors in the filter become clogged. These can be carefully cleaned with a soft

brush or soft scouring pad. How often this will need to take place depends on the clarity of the water

used for filtering and the total volume of water which runs through the filter.

Other water storage tanks

Several other tanks of various sizes are positioned around the house and garden to supply vegetable

gardens, flush toilets and taps inside the house. The volume of water used to flush the toilet can be

reduced by simple modifications of the toilet. Also a versatile shower unit, made from a bucket and

garden shower rose, uses less than 9 litres of water for a shower and can accept either solar heated

water or water heated in a kettle or on the stove. Aroma therapy oils can also be added. Also there are

various ways of reducing the volume of water used for hand washing.

Self supply and do-it-yourself

All these developments have been undertaken with the view to becominge more self sufficient in terms

of water availability, quality and economy of use. All the subjects mentioned here have been been

described in more detail in specific manuals written by Aquamor and placed on the Aquamor website

www.aquamor.info.