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Home    >    The Manifesto    >     4. Bioclimatic Design    >    Water Management

Water Management

Access to clean water is essential for children's survival and development. Increasingly water sources are under threat from contamination, which impacts not only on the health of children, but also on the social, environmental and economic development of communities. In rural areas of East Africa, one third of villages have no access to a valid water source. The main technology options are boreholes (44%), shallow wells (24%) and protected springs (21%). Tap stands, public kiosks and rainwater harvesting represent 11% of water sourced. Access to mains water supply is restricted to urban areas, where it is estimated 20% of premises have a safely managed water supply.

Rainwater Harvesting

Schools often have a large roof catchment area for rainwater harvesting that can substantially augment a school’s water requirements.

East Africa is an ideal location for rainwater harvesting as a primary source of clean water. Rainfall data and the available catchment area are required to determine available water supply. Demand is calculated based on the number of users and their average water consumption. If supply does not meet the demand then other sources  of water will be required to meet the shortfall. Untreated rainwater can be used for irrigation and toilet flushing, but it must be treated for drinking and wash hand basin use.

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Nakapiripirit Vocational Institute  The new workshop is provided with four PVC water tanks to harvest water from the building

First Flush Device

A first flush device diverts the first rain away from the storage tank to keep stored water as clean as possible. First flush water can be used for irrigation.

The first rain of a storm cleans the roof of dust and debris, which should be diverted before it enters the rainwater storage tank. A first flush diverter directs the first rainwater into a chamber, which contains a ball to stop the contaminated water from escaping. There is a valve or small hole at the bottom so that first flush water, which is often rich in organic matter, can be piped off for irrigation. As a general guideline first flush devices should remove approximately ten gallons (37.8l) of water per 1,000sqft (92.9sqm) of roof/catchment area.

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This rain filter diverts foul water through the down pipe using centrifugal force and filters clean water through a stainless steel screen.

Borehole Water

In sites where connection to water mains is not feasible then a borehole could be a suitable solution to supplement rainwater harvesting.

A borehole is a narrow hole made in the ground to allow for abstraction of groundwater, which is often quit pure especially when it has passed through fine granular soils. Boreholes can usually be relied upon for year round water supply. They should be sited at least 30m away from pit latrines or other sources of contamination. Water is extracted using a manual or motorised pump, which may be solar-powered to reduce on-site energy demand. Extracted water may be stored in tanks to reduce continual operation of the pump.


This rain filter diverts foul water through the down pipe using centrifugal force and filters clean water through a stainless steel screen.

Filtering Systems

Raw eater no matter what its source should be treated in a point-of-use filtering system to ensure safe drinking quality water.

Raw water should be filtered, treated or boiled before drinking. Even after treatment water quality may be compromised through unsafe handling and storage. For this reason, point-of-use filtering sstems are the preferred option for schools. Biosand filters are slow sand filters that offer a low energy alternative to water boiling. Concrete biosand filters can be made locally. Plastic biosand filters such as the Tiva filter are an increasingly common and affordable option in schools, costing $81 with a capacity of 40L per day. The Advanced Tiva Water Filter uses sand, a carbon membrane filter and UV treatment to process 6,000L per day at a capital cost of $5,000.


A typical plastic biosand filter, shown here at Kyere Primary School, Uganda, is the most common and affordable option for schools.

Water, Sanitation & Hygiene

Access to adequate water, sanitation and hygiene facilities reduces illness and death, as well as improving physical and cognitive development.

Water-related illnesses are a main cause of absenteeism in schools, while worm infestations, of which 100% are attributed to poor sanitation and hygiene, have been found to result in a tangible loss of IQ. To combat this, it is imperative that schools provide clean drinking water, well maintained hand washing stations, gendered bathrooms and adequate facilities for girls to manage their menstruation. Water, sanitation and hygiene (WASH) lessons on good hygiene practices should be incorporated into the school curriculum.

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ECD &  F Centres  have child friendly hand wash stations outside each of the latrines to encourage good hygiene practices.

See Case Studies

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