Newsletter and Technical Publications
<Sourcebook of Alternative Technologies for
in Small Island Developing States>
PART B - ALTERNATIVE TECHNOLOGIES
1. TECHNOLOGIES GENERALLY APPLICABLE TO ISLAND STATES
1.4 Water Conservation
1.4.1 Water Resources Planning and Management
Planning and management of small island water resources and water
development projects are closely linked to the issue of maximising and
augmenting freshwater resources (UNESCO, 1991). This section provides an
overview of the use of these practises in small island settings.
The assessment of water resources and their sustainable yields is a
fundamental step in the planning of water resource development projects.
Conventional water resources (e.g., surface water, groundwater, and
rainwater) need to be thoroughly assessed and their use maximised before
unconventional options (e.g., desalination and importation) are
considered. Conjunctive use of different classes of water should always be
considered in such assessments. Often rainwater catchments and shallow
groundwater sources, either fresh or brackish, can be, and often are, used
conjunctively, even on the smallest of islands. Rainwater may be a
suitable option for the most basic of needs, such as drinking and cooking,
leaving the more saline water for other uses, such as bathing and washing.
Where existing or potential water supplies are scarce, the use of dual or
multi-quality supplies are alternatives to be considered (e.g., using
seawater for toilet flushing).
In the planning and design of water resource development projects for
small islands, certain basic criteria should be adopted. Simple, proven
designs, which have been used in similar conditions, should be promoted.
However, it is important to recognize that technical criteria from other
regions are only to be used as guidance, and must be adapted to suit local
conditions, taking into account local environmental conditions, social
customs, and community needs. Locally-available materials should be used
where possible to minimise import costs, and materials and equipment
should be standardised to minimise the level of knowledge or experience
(and, more practically, the variety of spare parts required) for operation
and maintenance. Diversification of technologies is a particular problem
when materials and equipment is received from donor agencies. To avoid
this problem, it may be necessary to specify preferred and well-tested
equipment as a prior condition to receiving aid funding. In any event,
corrosion-resistant materials should be used in water supply construction
in SIDS due to their proximity to the sea and airborne salt spray.
Wherever possible, operation and maintenance requirements should be such
that they enable village-level operation and maintenance. Using renewable
energy sources (e.g., solar- or wind-power), which are typically available
in abundance in SIDS, for pumping should be considered as a means of
minimizing operating costs.
Appropriate protection and management policies are essential for water
resource development. Controls on abstraction must be introduced and
backed by enforceable legislation to ensure that over-utilisation of water
resources does not occur. Water resources also should be regularly
monitored for quantity and quality and necessary remedial action taken to
prevent over-utilisation or degradation. Appropriate water quality
criteria should be set by each country. Guidelines (e.g., WHO, 1993)
should be adapted to suit local conditions. For example, salinity criteria
(e.g., chloride ion concentrations) need to be carefully considered in the
knowledge that island populations are often accustomed to higher
salinities in drinking water than are specified in many guidelines.
Provided there are no adverse health or environmental effects, adapting
guidelines to suit local conditions is often appropriate. Such actions
help to conserve and manage available resources so as to make optimal use
of conventional water resources.
Where freshwater resources are very limited, non-potable water use
should be encouraged for bathing and washing where practicable. Dual piped
systems, one with potable and the other with non-potable water (e.g., salt
water), can contribute to reducing the demands on potable water reserves.
Other conjunctive-use schemes (such as rainwater storage) may be
considered where piped systems are not present (e.g., use of non-potable
well water for bathing and washing). This is particularly appropriate in
crowded areas where homes or living quarters may be located above or
adjacent to water supply sources. Demand management is important for water
resources management on small islands. In urban areas, in particular,
demand management measures should include an appropriate pricing policy
combined with consumer information on the need for reduction of waste.
Waste reduction measures may include reducing water supply pressure to
minimum levels, installing low-flow fixtures, and using water conserving
devices. An active leak detection and repair program is also essential for
both delivery systems and individual household systems, as many water
supply systems often have substantial losses due to leaks. The savings in
water can often have positive benefits in delaying the need for
development of new, often more costly water resources.
Land management is very important for water resources protection, and
especially so for protecting fresh, groundwater lenses from contamination.
This is particularly important on islands with highly permeable soils and
shallow water tables. Water reserves, or protection zones, should be
established wherever possible, although such actions may result in
conflicts over land ownership and can lack cultural acceptability. On
atolls, it may be possible to reserve individual islands for water supply
purposes (UNESCO, 1991; Falkland, 1991). Such reserves should disallow
land uses which have the potential to pollute water resources, including
such land uses as residential, commercial and industrial development.
Where land resources are very scarce, an alternative approach would be to
site such development on the edge of the island or as far as practicable
from the centre of the freshwater lens. Transmigration, or resettlement of
people from overcrowded islands to other locations, may be necessary in
extremely serious situations (relocation has been effected in the past,
and may be necessary in the future, in the event of major natural
disasters such as earthquakes, volcanic eruptions, overtopping by waves,
or extreme drought). Such disasters not only affect water supplies but
also most of the other aspects of a small island community infrastructure.
To maximise the quantity of fresh, groundwater, it may be prudent to
selectively clear vegetation, particularly coconut trees, to reduce
transpiration. This selective process should be properly planned as
coconut trees are a source of food and drink, shade and materials for
building, as well as other purposes (likewise, other large trees, may also
need to be assessed as to their suitability in groundwater abstraction
areas). Similarly, to maximise the quality of fresh, groundwater, it is
necessary to maintain adequate spacing between onsite sanitation systems
(pit latrines and septic tanks) and water supply points (dug wells and
boreholes), and to take into account groundwater flow directions. Because
guidelines from non-small island states may not necessarily be applicable
to the conditions prevailing in SIDS, specific guidelines should be
adopted to suit local hydrogeological conditions. To this end, a UNESCO
study is being carried out in Tonga to assess issues such as safe
distances between wells and sanitation facilities on small islands. Where
possible on small, coral islands, water supply extraction facilities
should be located toward the middle of the island and sanitation and solid
waste disposal facilities should be situated near the edge of the island.
It might also be of benefit to review the current sanitation methods used
on such islands in order to determine the relative advantages of
alternative technologies in conserving water and protecting groundwater
resources. In certain circumstances where land disposal of wastewater is
not practical, it may be necessary to pipe sewage from the island via an
ocean outfall, and, where environmental safeguards are paramount,
extensive and costly sewage treatment may be necessary prior to such
discharge (Gersekowski, 1992). To minimise other sources of pollution,
restrictions on location of animals, such as pigs and poultry, and the
siting of graveyards, bulk storage facilities and industrial facilities,
may be appropriate. Potentially harmful chemicals and other substances
should be located away from water supply sources.
Level of Involvement
The community should need and want the water resources development
scheme. The desire for the scheme should be genuine and the community
should have sufficient resources to operate and maintain the system once
it is implemented. Project workers, if from outside the beneficiary
community, should get to know the community and its leaders, helping them
to learn how to implement and maintain the scheme, and learning from the
community about their specific needs relative to the system design. There
should be a management committee for the scheme ensuring that all groups
are represented, particularly the women of the community
To achieve real community ownership, participation by the community at
all stages is essential. Participation should begin as early as possible,
and, ideally, the community should take the lead in the planning and
implementation of the selected scheme. In some cases, this may require
training to strengthen local capabilities for financial control and
project management, and to create a degree of familiarity with the
technology and its operation. The selected technology should be least
complex technology that will meet immediate needs, capable of being
expanded to accommodate future needs, and within the capability of the
community to install and maintain. Time scales relating to project
implementation should be flexible enough to allow the community to work at
its own pace, using methods appropriate to the community.
Participation by the community is a fundamental component of any water
resources development project; it is both the means by which projects are
implemented and the essential ingredient for project success and community
development. In this regard, cost recovery schemes should be considered in
order to recover all or part of the capital cost of a project and foster
the community=s sense of ownership. Whether or not a project can be
sustained depends crucially on the community=s willingness to take
responsibility for the operation and maintenance of selected system. This
willingness is often apparent by the extent to which people participate
during the planning and implementation of the project. Social scientists
have devoted much attention to the study of community participation, and
most agree that, while many programmes pay lip service to the concept,
very few programmes realise or appreciate its full potential. Rather,
community participation is often viewed, mistakenly, as some kind of
injection which can be given to a programme at various points during the
project cycle, and, more often than not, as a nuisance for the technical
personnel geared to the more technical aspects of project design and
Further Development of the Technology
Training at technical, professional and managerial level is required as
an ongoing requirement to improve the skills of local personnel in the
assessment, development and management of their own water resources, and
the selection of appropriate water supply technology. The training of
women in the operation and maintenance of water and sanitation systems is
essential as it is the women who are most affected by faulty water and
sanitation systems. Recognition among water resources professionals of the
important role of communities in the design, operation and maintenance of
water supply systems is also critical and techniques for community-based
decision-making should be developed and included in professional training
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