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2.4 WATER CONSERVATION
2.4.1 Urban Water Conservation
The techniques included in this option take various forms and
include the following water conservation measures which may be implemented
by local authorities:
- The development of an appropriate tariff policy: Under this approach,
tariffs are levied as steep progressive rates, which subsidize the very
poor and may also offer special rates for the promotion of industry.
However, cost recovery is essential in order to ensure a sustainable
operation, and pricing levels should be such so as to guard against
- The metering of individual stands and flats: The metering of
individual properties puts the burden for water conservation on the
consumer, which is the most effective means of ensuring urban water
- The institution of efficient meter reading and billing mechanisms:
Well-maintained and working meters, read accurately and regularly, and
followed-up by efficient billing procedures ensure that consumers do not
abuse municipal water supplies. Monitoring of such systems for changes
in rates of consumption and rates of return or payment of bills provides
accurate data for planning purposes. Relating consumption paid for to
the amount of water produced provides a check on unaccounted for water
and can alert the water utility of leakages or breaks in the supply
- The use of water-saving fittings: By using water-efficient fittings
such as low flush toilets, low-volume shower heads and taps, and flow
limiters, consumers can achieve the same degree of benefit from a lesser
volume of water.
Extent of Use
Water conservation approaches have met with varied responses in the
- Development of appropriate tariff structures is generally a weak area
in most countries in Africa. While some form of tariff structure exists
in all of the countries of Africa, those that have attempted to set
economic tariffs still fail to separate the water account from the rest
of the municipal (general) expenditure account, which typically negates
the benefit to the water utility of setting economic tariffs. (Such
benefits, include the availability of finances to update or expand their
production and distribution networks; by considering water revenues as
general revenues, the water utilities are forced to compete for funds
with all other municipal services.) For this reason, privatization of
water services is being encouraged in a number of African countries.
- Although metering is encouraged in most countries of Africa, not all
consumers are metered appropriately. Bulk supplies and stand posts are
common in the rural areas, while, in large cities, only the affluent
urban areas are typically metered.
- Billing mechanisms are in place in most countries of Africa, but
these are not properly monitored. Lack of monitoring of payments
significantly reduces the recovery rate for monies invested in water
treatment and distribution. Unaccounted for water, including illegal
connections, accounts for up to 30% of potable water generated in most
countries. Likewise, lack of monitoring and efficient bill collection
generally means that development of water distribution systems lags well
behind the rate of urbanisation.
- Water saving fittings are being promoted in the dry countries of
Africa, especially in Southern Africa.
Operation and Maintenance
The techniques described above are largely social strategies aimed at
conserving water. Additional actions may be needed to operationalise these
strategies. The following operation and maintenance techniques may be
applied by water utilities when implementing water conservation measures:
- Pressure and flow control: Municipal water distribution systems
normally have different ages. The tendency to leak is highest within the
older portions of the network. To minimize leakages, it is essential
that these different regions are zoned, and supply pressures be varied
accordingly. Scheduled maintenance and leak detection systems are
- Consumer information programming and conservation promotion:
Conservation is promoted through the formulation of rules and
regulations for promoting efficient use of water and minimizing wastage,
and by effectively informing consumers of measures to reduce wastage of
- Distribution system maintenance: Corroding pipes cause leakage.
Replacement of corroded pipes with non-perishable pipes, such as PVC
piping, reduces water losses through leaks and ensures insofar as
possible an uninterrupted supply to consumers. Regular maintenance
reduces the risk of service interruptions due to breaks in the supply
- Monitoring and policing in cases of misappropriation, theft and
fraud: Replacement of faulty meters, training of meter readers, and
efficient administrative oversight can detect and reduce illegal
connections to distribution systems, thereby protecting the revenues of
the water utility and reducing losses within the distribution system.
For efficient operation and administration, it is essential that the
network be divided into district meter zones and that an accurate and
up-to-date map of the distribution system is made and maintained.
Level of Involvement
The urban authority is usually the major player in promoting water
conservation. However, Government agencies as in some municipal areas may
be the single largest consumer of water and should be enlisted to support
the water conservation promotion program. Civic organisations and NGOs can
also play a role in consumer information programming.
The costs vary depending on the measures taken, but more efficient use
of water reduces or delays need for expenditure on new water supplies
while ensuring that revenues are available for this purpose. Informational
programming costs are minimal, especially if combined with other
informational programming, such as school curricula in environmental
sciences, health awareness campaigns or similar on-going activities, while
provision of water-saving hardware to replace conventional plumbing
supplies may be more costly. Manpower costs to improve distribution system
maintenance and management are also relatively high but are typically
offset by the increased revenue generated from these actions.
Effectiveness of the Technology
With effective leak detection and pipeline repair programmes in place,
it has been categorically shown that the real savings far exceed the
costs. For example, low volume flush toilet cisterns can reduce the volume
per flush from 15 to 8 litres.
Use of water conservation techniques is appropriate in all countries.
Use of these techniques can result in saved water that can be put to
other uses. There is a significant reduction in costs, and an increase in
water utilization efficiency (and revenues). Capital projects for the
construction of new water reservoirs may be deferred to a latter date, or
capital made available for expanding the distribution system to meet new
Some expenditure is necessary to put a water conservation programme into
action. Once the system is in place, use of water saving fittings may
reduce wastewater flows to below the design flows for older trunk sewers
and can sometimes result in blockages, necessitating a system redesign and
retrofit. While the cost of such actions may be offset to a degree by
increased revenues generated by charging consumers an economic rate for
water, services charged at economic rates may be too expensive for the
poorest segment of the community to afford, requiring additional
arrangements to minimise illegal connections to the system.
No cultural problems have been noted, although the societal implications
of charging economic rates for water should be recognised and accommodated
in an equitable manner.
Further Development of the Technology
There is need to undertake studies to correlate soil resistivity with
leak occurrence in, especially, steel water mains, taking into account
pipe age and technical specifications. Research is also necessary to
determine the most appropriate management systems required for water
conservation in Africa. In cases where low volume fittings are adopted, it
is necessary to consider their impact on trunk sewer slopes and reduced
Castle Brass Holdings (Pty) Ltd., Post Office Box 4082,
Luipaaardsvlei 1743, South Africa.
City Engineer's Department, Post Office Box 4323,
Johannesburg 2000, South Africa.
American Waterworks Association s.d. Water Conservation Management.
City Engineer's Department 1989. Water Loss Analysis on Municipal
Distribution Systems. Water Research Commission Report No. 157/1/89,
Holland, J.R. and S.M. Holland 1994. Urban Water Supplies
Conservation Study for MLGRUD. Emergency drought recovery and mitigation
National Building Research Institute 1986. Water Economy Measures.
Guidelines for Local Authorities. Water Research Commission, Pretoria.
Jeffcoate, P. and A. Saravanapavan 1987. Working Guidelines for the
Reduction and Control of Unaccounted For Water, World Bank Technical
Paper No. 72, Water Supply Operations Management Series, Washington, DC.