Cover Image
close this bookPriorities for Water Resources Allocation (NRI)
close this folderDomestic water use
View the documentPaper 5 Domestic water use: engineering, effectiveness and sustainability
View the documentPaper 6 Domestic and community water management

Paper 5 Domestic water use: engineering, effectiveness and sustainability

Richard Franceys

Water, Engineering and Development Centre, Loughborough University of Technology

Summary: A domestic water supply is a basic need required by all, justifying subsidies and donor aid through direct health benefits. This paper considers what sort of water supply is needed to be effective, the role of engineering in water supply provision and an approach to ensuring sustainability.

Domestic water use

Domestic water is used primarily for drinking, cooking, washing and bathing. In some parts of the world an equal amount is used for transporting domestic waste down sewers. The main justification for giving aid or subsidising the provision of an improved domestic water supply is the health benefit. However consumers normally demand improved water supply primarily for convenience, for which they are often willing to pay. Because convenience influences the amount of water used which affects health benefits, these two factors, health and convenience, have to be kept in balance.

At present 1089 million (82%) urban dwellers in the lower-income countries are believed to have a suitable water supply along with 1670 million (63%) of the rural population. However, many of those counted as having an adequate supply suffer because it is inoperable or at best is working only intermittently. In addition to improving existing supplies, the population requiring a new service by the year 2000 is estimated to be 813 million people in the urban areas and 1301 million in the rural (UN, 1990).

Recognising this enormous and continually increasing demand, there are three key issues in domestic water use: What is an adequate water supply and who will have access to it? How can the supply of domestic water be financed and managed? Will there be enough water to meet the 'adequate' demand?

What is an adequate water supply and who will have access to it?

It is estimated that diarrhoea caused by inadequate water supply and sanitation results annually in deaths of 4.6 million children under the age of five. Improvements up to an 'adequate' system can lead on average to a reduction in the overall incidence of infant and child diarrhoea by one quarter and total infant and child mortality by more than one half (Warner and Laugeri, 1991). Although children suffer most acutely from inadequate water and sanitation the recent outbreak of cholera in Latin America led to a reported 251 568 cases resulting in 2618 deaths whilst the on-going outbreak in Africa had 45 159 cases and 3488 deaths over the same sixmonth period (WHO, 1991). In addition, infections such as Guinea worm lead to serious debilitation in adults and loss of productive output, with attack rates ranging from 10 to 40% of the population leaving victims completely disabled for periods lasting 3 to 29 weeks (Smith et al., 1988). In addition to the health problems, many people (almost all are women) still spend hours each day collecting water from a distant source which also leads to a potential loss of productive output.

The agreed slogan for the water sector for this decade is "Some for all, not all for some". Kalbermatten (1991) reports that at present 70 to 80% of funds go to serve 20 to 30% of the population. The population served are mostly the rich who have access to formal housing and also the political power to achieve the average capital expenditure of $ 200 per caput for household water connections and $ 350 per caput for sewerage (Christmas and de Rooy, 1990).

The quantity of water and the proximity of the supply point to the home have been found to be more important than actual water quality in improving health. Even then water supply is only effective when linked with adequate sanitation. Therefore an 'adequate' water supply following the "Some for all, not all for some" guideline will be in the region of 20 to 40 lpcd (litres per caput per day) within one kilometre of the household in rural areas as a first priority and within 100 metres as the second priority (not necessarily at conventional quality 'standards' but following WHO guidelines). In urban areas standposts delivering 40 lpcd within 100 metres are the first priority with yard taps designed to supply 60 lpcd as second priority to meet the health criteria (Cairncross, 1990). To define these service levels as adequate does not preclude higher levels for those who desire them. However the higher water use resulting from house connections with its subsequent increase in drainage requirements should not be seen as a suitable service to subsidise. These 'adequate' levels of water service can be provided for an estimated investment of $100 per caput in urban areas and $ 30 in rural areas, a significant reduction in cost.

How can the supply of domestic water be financed and managed?

The estimated investment to meet the demand for an adequate water supply (and sanitation system) from new or unserved consumers in lower-income countries is approximately $ 50 billion per year. Average spending is only $ 10 billion per year and of the $ 3 billion coming from external sources only about 4% is spent on 'low-cost technology' (Christmas and de Rooy, 1990). To put this into perspective, the English and Welsh water companies alone are expecting to invest $ 6 billion this year to upgrade services.

In addition, for existing water supply systems, the World Bank (1990) reports that the average effective sale price of water is only about one-third of the marginal cost of producing the water. This shortfall in finance for both capital and recurrent costs leads to the downward spiral of institutional inadequacy common to many countries. Staff are demoralised because of low salaries and lack of equipment and limited coverage which leads to poor service leading to increased reluctance from consumers to pay even the small tariffs. This, along with erratic government funding, leads to even fewer resources for the sector and even worse service provision and even greater inequity in service coverage. Staff have to promote high-cost technology with external contractors in order to finance the necessary informal (and illegal) additions to their salaries that leads to further inefficiency and waste.

· The major problem of urban domestic water supply is institutional inadequacy linked to lack of finance.

But consumers are willing to pay for water as has been shown by the studies of vendors. One estimate (Cairncross, 1990) suggests that vendors are now serving perhaps 20 to 30% of the urban population with total cost of water at 20% of household income, significantly above the official tariffs and also above the 3 to 5% of income often quoted as acceptable. Clearly even low-income consumers are willing to pay for the service they want. However, public health engineering, as in so much of engineering where 'the professional knows best', has nearly always used a supply driven approach. It actually needs to be demand driven. This enables customers to show their demand through their willingness to pay for different levels of service. Only when this change is made will it be possible to achieve the required substantial reduction in costs of services (through efficiency and the use of appropriate technology) and the equally necessary mobilisation of additional funds from consumers. Jackson (1991) makes the point strongly: "there is no point in dealing with details of engineering design while the financial issues remain unresolved..

It is necessary to finance urban water supply through rising block tariffs with an affordable household 'lifeline' charge for an 'adequate' supply rising to average incremental costs for metered users who want household connections. Only then is it possible to achieve the vital institutional improvements because there is some hope of the necessary funding being available. Once there is general acceptance of the need to raise finance for the sector directly, institutional development has to be considered as the next step in improving water supply. This does not mean adding a training component (or even a 'human resources development' component) to an engineering contract. Rather it means enabling the institution to reform itself so that it can then determine what sort of engineering is really needed. Because it is the institutions of water supply that are failing all around the world which cause the majority of apparent engineering failures. WASH (1988) suggests that institutional development is dependent upon organisational autonomy, leadership, administration and management, commercial and consumer orientation and human resources.

Water supply institutions are most likely to fail because of their place within politically controlled government departments or municipalities. Organisational autonomy (within a politically controlled framework of responsibility and authority) is a necessary pre-condition to effective water supply. New organisational models that use the private sector to a much greater extent such as management contracts or leasing (affermage) are required. Transfer of equity as in complete privatisation will probably not bring significant benefits to utilities in low-income countries in the medium term.

The change that is required subsequent to greater autonomy is a commitment to a commercial orientation. This is not a commitment to profit making or to profiteering but to providing the most efficient and effective service to the whole range of consumers in a commercial style whilst retaining a basic needs service to low-income consumers. This will require enhanced leadership of the institutions and the type of team-building and quality circles and reduction in middle management that has become such a feature of the commercial developed world. It will require the introduction of clear performance indicators and sensible (modest?) management information systems. It will particularly require the upgrading of accounting systems such that there is accounting for fixed assets as well as recurrent costs in order to gain some sort of understanding of the surplus or loss generated from operations in any year. Zero-based or Priority-based budgeting systems will have to be introduced with managers directly responsible for a clearly defined cost centre.

To be effective with a new commercial orientation, institutions also require a new orientation towards their consumers or rather customers. Customers who pay the appropriate tariff have to be cared for and have the right to expect a suitable service.

In urban areas where economies of scale demand integrated systems for water supply (not necessarily true for sanitation) dis-economies of management may demand the separation of the roles of bulk provision of water (production and wholesaling) from the distribution and sale (retailing). Moving the institutional/household boundary back from the property line to some form of site or area boundary can enable a community or private enterprise to take responsibility for managing a distribution network and collection of revenues (retailing). Alternatively the (private?) provision of communal bath houses for bathing, laundry and sanitation is a possible approach to water retailing and on a smaller scale still there can be an individual with a standpost concession.

· The major problem of rural domestic water supply is institutional inadequacy linked to lack of community involvement.

There has been much discussion regarding the need for community participation. Having often failed in this form (community participation became what its name implies, the community participating, often reluctantly, in an agency scheme) the recommendation is now to promote community management. This implies that the community have the responsibility to manage all aspects of their service provision, from planning through finance to implementation, operation and maintenance. This is valid for discrete, community level technologies in rural areas, but the community or household does not always know what they want or what the options are. A new customer orientation stresses the requirement for service ('the customer is always right') but also implies a responsibility to determine (through 'market research' rather than 'social surveys'?) the right product for the right group of people at the right price.

Perhaps what is required is a 'services supermarket' where potential customers can examine the available technologies and discuss possible prices and installation services and credit terms (and available subsidies). This approach can work well for discrete technologies such as rainwater catchment tanks, hand-dug wells, handpumps, ram pumps and on-plot sanitation and can be adapted for communal gravity flow water and other rural development systems.

Some of these ideas might sound familiar as the need to promote efficiency and effectiveness in public services in UK faces similar challenges in becoming more commercially and consumer oriented. The Citizen's Charters, privatisation (in its broadest sense) and internal markets may represent a more useful UK export to low-income countries than sophisticated engineering.

How might this institutional development (revolution?) be achieved? It can be assisted and encouraged by consultants but, like all development, ultimately it has to come from the people most concerned. Therefore ways have to be found to introduce ideas and suggest changes whilst allowing the institutions themselves to find their own way forward within their own political framework.

Consultant counterparts trying to justify their existence by telling institutions how to develop on a daily basis will not be effective. What is required is continuing and more focused support for human resources development - through extension of twinning arrangements, postgraduate courses which emphasise management (MBA for Utilities?), higher degrees by research into management issues, professional networking (as in ODA-supported GARNET), promotion of professional associations, supported by intermittent but regular consultant visits. The aim of all this to enable existing institutional staff to become their own management consultants so that they can bring about effective, sustainable institutional change themselves.

Will there be enough water to meet an 'adequate' demand?

There is a growing concern that the dramatic growth in the population of the urban areas will lead to a shortage of water. Undoubtedly bringing a dispersed population together demands a much greater point supply than was needed previously . Engineering can be effective at developing sources ever more distant from a city and transporting water over long distances. Where water sources are limited clever engineering can desalinate but at high cost. Domestic water demand management is one way of ensuring that there will be sufficient water at an economic cost. The major areas of demand management to consider are the use of technical, social and economic techniques and most importantly the choice of sanitation.

· The use of technology for water saving depends upon leakage control, pressure reduction and the introduction of reduced water-using appliances such as aerator taps and showers and low-flush toilets. These technical solutions are simple and effective though require a significant initial investment. In the case of household appliances some form of promotion is usually required with the support of changes in bye-laws.

· Social techniques of demand management refer to the use of education and legislation. Often these approaches appear to have most value at special times of drought but in the long term, as attitudes towards use of resources change, they may have a significant part to play in continuous demand control.

· Economic techniques depend upon tariffs and metering. For tariffs to have an effect on water consumption they have to be linked with meters. Whilst at first sight it is entirely logical to have a system whereby people pay directly for what they consume, the problem with meters is that they are expensive to install and maintain. There has been a 13% average reduction in domestic water use in the UK metering trials but it is anticipated that this will decrease as coverage increases, for most of the reduction is achieved in the richer suburbs with large gardens. Binnie (1992) also reports that the cost of meter installation rises significantly as coverage increases (the simplest properties tend to be metered first).

If in this country where meter installation would cost only 2% of average annual income we have not yet been persuaded of their value, is it reasonable to expect them to be used in countries where the cost represents 28%? The reduction in demand may not be worth a reported increase in water supply costs of 25% in low-income countries. Alternatives to consider are the use of flow restrictors in delivery pipes or some form of design limitation in pipe size and pressure to limit overall supply to low-income, subsidised consumers. Another approach is to consider the use of district meters with private or community vendors selling on the water as described earlier.

· Although this paper concentrates upon domestic water use, sanitation has to be considered because of the implications for water demand (in addition to the health implications). Demand for improved sanitation by the year 2000 is estimated to be 947 million people in the cities and 1676 million people in the rural areas. If this total of 2623 million is to receive sanitation through conventional means the increased demand for domestic water supply will be insupportable when considering an average four flushes per day at 10 litres (or even a reduced 5 litres) per flush.

On-plot sanitation (very improved latrines or septic tanks) can reduce per caput water demand by between 25 and 50% (as compared with sewerage) whilst providing all necessary convenience, cleanliness as well as affordability. Currently the focus of an ODA research project, many countries still see on-plot sanitation in urban areas as worse than second best. Intriguingly it is reported that in Japan only 42% of households are connected to sewers - "the rest have to make do with septic tanks emptied by suction truck once every few months" (The Independent, 1991).

The major fear regarding on-plot sanitation has been the danger of pollution reaching the groundwater. This pollution is represented primarily by nitrates as pathogens do not normally travel any significant distance. In the successful Maputo sanitation programme there has been a measurable rise in nitrate levels in the shallow groundwater but following experience in other areas with higher than recommended nitrate levels there have been no recognisable health implications. If in the end problems do arise with local deterioration in shallow groundwater quality the figures suggest that it is always more economic to pipe clean water in to a city than it is to pipe wastewater out.

All these techniques show that domestic water demand can be significantly reduced. However, in the context of overall water resources it is necessary to recognise that only 15% of the water abstracted from the hydrological cycle is used for non-irrigation purposes and of that only one third is directly for domestic use. This puts into context the apparently high wastage of 34% average unaccounted for water - especially when it is suggested that 'losses' in irrigation, representing 85% of water abstracted, are of the order of 60%.

The choice therefore becomes clear. In a year, 1000 cubic metres of water may be used either to provide water for 80 people or to grow food for between 1.6 and 3 people. This imbalance of between 1:30 to 1:50 in the ratio for daily water use to irrigation-grown food suggests, that in the context of competing demand for water, then domestic water use should win every time. It is far more economic to move food from a rain-rich area to a dry area than it is to move water. "In some regions it has been demonstrated that more efficient agricultural irrigation would release sufficient water to meet all additional urban needs" (Okun and Lauria, 1991).

Water for irrigation and for domestic use must be valued as an economic good. If this policy was followed, particularly with regard to groundwater abstraction, then many apparent shortages of drinking water could be overcome.


To be effective, domestic water supply requires a moderate amount of water of moderate quality as close to home as possible. To be sustainable, water supply requires revitalised institutions that have control over their finances. What are the implications for engineering once domestic water is seen to have priority over irrigation water? This paper has not concentrated on engineering for after all, what is difficult about connecting a power supply and some lengths of pipe to a pump and turning on? This gross oversimplification is meant to suggest that the basic engineering is relatively easy though for the operation and maintenance to remain manageable unfashionable technologies such as slow sand filters must be used wherever possible. Optimisation of the engineering is a challenge - but remains worthless when the underlying problems are institutional.

The extra percentage points of efficiency are only achieved once an effective institutional system is in operation. Even then, engineers must avoid the temptation to concentrate on the functional aspects of planning and think more of the normative aspects. UNICEF imported over a million small plastic taps into Nigeria to fix to water pots. Now that people no longer have to dip a contaminated container into the household water store health benefits are more assured than when the effort went into achieving ever higher 'engineered' quality of water at the standpost. The objectives have to be considered before the means.

To maximise benefits from investment of aid in domestic water use it is necessary to draw back from the engineering and enable institutional development based on commercial and customer orientation. "Capacity building and the institutional and human resources development effort that are integral to it, is essential to provide program and project sustainability. (Okun and Lauria, 1991). Without this targeted investment we will continue to see inadequate and intermittent supplies with the resultant disease and dis-ease afflicting tens of millions.


BINNIE, C. J. A. (1992) Demand management, tariffs and metering. Paying for Water Symposium, IWEM, London.

CAIRNCROSS, S. (1990) Water supply and the urban poor. In: The Poor Die Young, HARDOY, J. E. et al. (eds) Earthscan Publications, London.

CHRISTMAS, J. and de ROOY, C. (1990) The Decade and Beyond. at a Glance. UNICEF, New York.

THE INDEPENDENT (1991) quoting report of the Construction Ministry in Japan, 11 March, 1991.

JACKSON, B. M. (1991) Water, sanitation and money. In: Infrastructure, Water, Environment and People, Proceedings of the Seventeenth WEDC Conference, Nairobi, Kenya, Loughborough University of Technology.

KALBERMATTEN, J. M. (1991) Water and sanitation for all, will it become reality or remain a dream? Water International, 16, 121-126, IWRA.

OKUN, D. A. and LAURIA, D. T. (1991) Capacity Building for Water Sector Management. ALAENTS et al. (eds) IHE/UNDP.

SMITH, G. S., BLUM, D., HUTTLY, S. R. A., OKEKE, N., KIRKWOOD, B. R. and FEACHEM, R. G. (1988) Disability from Dracunculiasis: Impact on Mobility. Imo State Government and UNICEF and LSHTM and University of Lagos and WHO.

WARNER, D. B. and LAUGERI, L. (1991) Health for All: the Legacy of the Water Decade. Water International, 16, 135-141, IWRA.

WASH, (1988) Guidelines for Institutional Assessment, Water and Wastewater Institutions, Technical Report No. 37, CULLIVAN, D. et al., Arlington.

WHO (1991) The Ark, No 8.

WORLD BANK (1990) FY90 Sector Review - Water Supply and Sanitation; Infrastructure Department. The World Bank, Washington.

UNITED NATIONS (1990) Report A/45/327, Secretary General of the Economic and Social Council to the UN General Assembly, New York.


Several questions were concerned with the relative value of water for domestic, irrigation and industrial use. It was pointed out that some industrial processes, like irrigation, used a great deal of water per unit product and that there is scope for considerably improved water use in many cases. For high-value crops the cash return per unit water could be attractive.

In the light of ODA's proposal to place little emphasis on health benefits during the appraisal of water projects and the speaker's reference to global figures for health improvements related to water supply, he was asked if case histories of such improvements were available. He replied that he was involved in a current West African study to do with reduction in guinea-worm infection following clean water provision.