Newsletter and Technical Publications
<Sourcebook of Alternative Technologies for
in Small Island Developing States>
PART C - CASE STUDIES
5.1 Augmenting Freshwater Resources in Kiribati
Kiribati consists of three main island groups scattered over 3 million
km2 of the Central Pacific, between latitudes 4° N and 3°
S, and longitudes 172° E and 157° W. The total land area is
810.8 km2, comprising 33 low-lying coral islands, 10 of which
are coral atolls (Figure 36). The Gilbert Island group consists of 17
islands (including Banaba, or Ocean Island) with a total land area of
285.7 km2. Tarawa Atoll, in the Gilbert group and the location
of the capital, consists of more than 20 named islets, the southern six of
which are linked by causeways. The distance between Tarawa and outer
islands in the Gilbert group ranges between 51 km and 600 km. The Phoenix
Island group consists of 8 largely uninhabited islands with a total land
area of just 28.6 km2 located some 1 750 km east of Tarawa.
The only inhabited island of the Phoenix group is Kanton (Canton) Island
with the land area of 9 km2. The Line Island group consists of
8 islands with a total land area of 496.5 km2, extending over
a north-south distance of 2 100 km, located at a distance of between 3 280
and 4 210 km east of Tarawa, and some 800 km south of Hawaii. This group
includes the largest island in Kiribati, Christmas Island (Kiritimati),
having an area of 388.4 km2. Most of the islands are not more
than 2 km wide, or more than 6 m above sea level, except Banaba in the
Gilbert group which rises about 87 m above mean sea level. The depth of
water wells in most cases varies from 0.5 m to 3.0 m.
Figure 36. Map of Kiribati.
Climate: The climate of Kiribati is dominated by that of the dry
equatorial zone, which extends as a narrow belt over the central Pacific,
and by an inter-tropical front in the zone of convergence of the
north-easterly tradewinds, which remain fairly constant between 5°N
and 8° N. Rainfall varies considerably, not only between islands, but
also from year to year. In an average year, annual rainfall in the Gilbert
group ranges from 1 000 mm in the vicinity of the equator, to 2 000 mm on
Tarawa, to 3 000 mm in those islands furthest to the north. In the Phoenix
Islands, annual rainfall is 1 000 mm and in the Line Islands annual
rainfall ranges from about 700 mm on Kiritimati to about 4 000 mm at
Teraina Island about 400 km to the northeast of Kiritimati. The central
and southern Gilbert group, Phoenix Islands and Kiritimati are subject to
severe droughts lasting many months. At such times, as little as 200 mm of
rain may fall in a year.
Types of Technologies Used: In Kiribati, there are several types
of technologies used to augment and maximise the use of freshwater
resources for domestic purposes (i.e., drinking, cooking and sanitary uses
only). The use of water for agriculture, industry and others is not
considered as top priority, and no attempt has been made to consider using
potable water for agricultural use due to the very limited potable water
resources on the low lying atoll islands. The types of technologies used
in the outer islands (rural areas) are solar powered pumps, windmill
pumps, hand operated diaphragm pumps, and piston hand pumps (locally known
as Tamana pumps). In the urban areas electric pumps are used in piped
reticulation systems. Groundwater is the main water source for drinking,
cooking and other uses. Rainwater is also widely used, but only as a
supplementary water source.
Open, hand-dug wells are the traditional method used by I-Kiribati
to obtain freshwater for their basic needs. As the depth from the surface
to the groundwater table is generally just a few metres, and the soil is
fairly easy to excavate by hand, open wells or pits, 1 m to 2 m in
diameter, are excavated to a depth of 30 cm to 50 cm below groundwater
table. The walls are usually supported by stones and the well is left
uncovered for everyone to scoop up water as needed. However, under the
guidance of the Ministry of Health and Family Planning (MHFP), and,
earlier on, of experts from various aid-donor agencies, certain
improvements have been introduced into the construction of these dug
wells. Concrete rings were introduced as support walls. These are placed
up to about one-half metre above ground level, and surrounded by a
concrete apron cast around the well to impede the seepage of mud, debris,
and other contaminants into the water. A concrete cover is placed over the
well, with an opening for drawing water out with a bucket.
Mainly on Kiritimati (Christmas) Island there are several infiltration
galleries, consisting of open trenches, each some 150 m long and
approximately 3 m wide, dug to about 50 cm below the water table, from
which groundwater is pumped by diesel-operated horizontal pumps. The sides
of the trenches are supported usually by slabs of coral stone, and,
sometimes, by sheet metal or timber. Boards cover the trench. There is no
treatment of the water. A more advanced design, introduced in recent years
and adopted by an on-going UNDP/UNCDF Project, includes, in addition to a
hand-dug well, a 100 mm diameter, slotted polyethylene pipe, extending
between 20 and 60 m on either side of the well. The pipe is laid at a
depth of 30 cm to 50 cm below water level, and the trench is refilled with
gravel. The well and the pipework "gallery" is located a few
hundred meters away from the village, primarily to remove the source of
water from sources of pollution in the village, but also to extract the
water from the freshwater lens at a location where its thickness is
greatest (and this usually occurs some distance inland from the village).
The freshwater is thus skimmed from the uppermost layer of the lens, and
from a larger water-table area, compared to a well alone, thereby reducing
the risk of upconing of the underlying seawater. Extraction of groundwater
from the well is by either hand-operated diaphragm pumps, solar pumps, or
Hand pumps are installed at convenient supply points in the village and
draw water from the well through a 32 mm to 50 mm diameter polyethylene
transmission pipe of up to 750 m in length. The pumps are of a plain
diaphragm type, suitable for the conditions typical of usual coral islands
(i.e., low, near-flat topography and shallow depths to the water table,
resulting in low suction heads). A system of this type usually consists of
up to three pumps drawing from the same transmission main, with each pump
designed to supply three families at an assumed per capita consumption
rate of 30 l/day. Several dug and covered wells have been equipped with a
hand pump, mounted on top of a concrete cover. The pump used in these
applications is either a semi-rotary, diaphragm type suction pump, or a
portable Tamana pump. The Tamana pump is an innovation developed by a man
from the island of Tamana in the southern Gilbert group of islands. The
basic components of the Tamana pump are 25 mm PVC pipe, usually up to 30 m
long; a 50 mm PVC pipe, 1.0 m long; a 25 mm to 50 mm, 45° PVC reducer
bend; a 25 mm elbow; a 25 mm PVC male adaptor; a foot valve; and, a piston
made of wood. A new design of piston, made of one-half inch PVC piping,
has proven to be more durable than the wooden piston and is now widely
used throughout Kiribati for extracting water for bathing and other
Where the distance from the well and galleries to the village exceeds
750 m, an horizontal electric pump is installed near the well and draws
water into a 50 mm to 63 mm polyethylene transmission main which
discharges into 2 or 3 storage tanks. Water flows from the storage tanks
through 32 mm to 50 mm distribution pipes feeding a number of stand-pipes
in the village (up to 20 standpipes may be served). The volume of each
tank is 9 m3 and each tank is intended to supply up to 60 households.
Electricity for the pump is generated by a set of photovoltaic panels,
without battery storage, designed to pump water for a rather
conservatively-calculated 6 hours of sunshine per day. The storage tanks
can be of ferrocement or concrete blocks, constructed on top of 1.5 m to
1.8 m high stands made of concrete blocks and reinforced concrete.
There are several types of solar pumps used in the country. The earliest
types are the Southern Cross and BP CR2-30 solar pumps. At present the
Public Works Division is using a newer type of solar pump designed by Mono
Pumps Australia. The technical specification of these solar pumps are
given in Table 6.
TABLE 6. Technical Specifications of Solar Pumps.
rate at 20 m head
||24 Volt DC 1/3 hp
|BP Pump CR2-30
||24 Volt DC 1/3 hp
||180 Volt DC 1 hp
Windmill pump systems are essentially the same as solar pump systems,
but rarely used. The problem with windmill pumps is that they are very
difficult to maintain and operate. Erecting the windmill tower requires a
special skill which is not often available locally. Also, the windmill
gear box is located at the top of the tower. Further, the wind itself as a
source of energy is found to be unreliable due to its intermittent nature.
Level of Involvement
Water consumption rates, determined by the Water Unit for planning
purposes only, range from 30 l per capita per day in rural areas to 50 l
per capita per day in urban areas, based upon consumption rates for
cooking and drinking water supply only. People are encouraged to use
alternate sources of water (rainwater and groundwater in the vicinity of
the village) for sanitary and other purposes.
Prior to the on-going UNDP/UNCDF Project, eleven villages had been
provided with solar powered water supply systems; namely, two villages on
Tabiteuea North Island were provided with a solar powered water supply
system using funds provided by the Norwegian Government, seven villages on
Nikunau Island were provided with a solar powered water supply system
using funds provided in part (for solar pumps only) by the South Pacific
Commission, one village on Arorae Island was provided with a solar powered
water supply system using funds provided by the Save the Children
Foundation, and one village on Tamana Island was provided with a solar
powered water supply system using funds provided by the United Nations
Development Programme (UNDP). Of these, the seven villages on Nikunau
Island had previously been supplied with pumped water using a
windmill-powered system installed in the 1960s using funds provided by the
World Health Organization (WHO). The windmill pumps were subsequently
replaced or supplemented with solar-powered systems installed using funds
provided by the South Pacific Commission (SPC). Two other windmill systems
remain operational; namely, one windmill in a village on Arorae Island,
and one in a village on Tabiteuea South (installed originally by WHO and
later rehabilitated by the Public Works Division using funds provided by
the Government of Australia). The windmill pumps last about twenty years
with proper maintenance, and, hence, most are near the end of their useful
life. Few windmill pumps installed in the late 1960s are working today,
and most are being replaced with solar pump systems, installed during the
UNDP/UNCDF project, which perform as well as, or better than, the
wind-powered systems. The only problem that is very often encountered with
the solar systems is that of a broken belt, but this can be fixed by the
Island Council plumber.
On South Tarawa, the New Zealand Government, and, later, the Australian
Government, installed a basic water supply system serving South Tarawa in
the 1970s (Figure 37). This system provided water primarily through public
standpipes. However, an increasing population on South Tarawa and a
cholera outbreak in 1977, resulted in the Government of Australia-funded,
Tarawa Water Supply Project. This Project provides reticulated water to
all the population of South Tarawa and to Buota in North Tarawa.
Construction work for the project was carried out between 1983 and 1987 by
the Australian Department of Housing and Construction. The system was
later improved and extended in 1989 by the Snowy Mountains Engineering
Corporation (SMEC), with funding again provided by the Australian
Government. Total capital investment by the Government of Australia to
date to this project amounts to approximately $6.4 million. Under this
scheme, water is pumped from collection galleries installed in two
freshwater lenses. There are 17 galleries on Bonriki, and 6 galleries on
Buota. Each gallery has a concrete- or fibreglass-lined well and each well
is equipped with an electric, horizontal helical rotor-type pump (a
Mono-type pump). The discharge pipes of all the wells are connected to a
collection pipe, into which chlorine is injected at the point where the 30
km long, 155 mm to 225 mm diameter rising main begins. The rising main
extends along the South Tarawa chain of islets, connected by causeways, to
the reticulated consumer areas where it is stored in elevated tanks, 4 m
above ground level (except the Betio tank which is at 13 m above ground
level). These tanks are filled from the rising main either directly or by
pumping from ground-level reservoirs connected to the main.
Figure 37. Map of Tarawa.
Based on extensive hydrogeological investigations, the sustainable yield
of the Buota and Bonriki lenses was estimated as 1 300 m3/day.
At present, some 1 250 m3/day are extracted. This amount is
supplied to a population of some 26 000, the Betio port, and several other
large consumers. Actual demand for water is far higher than 1 250 m3/day,
and the Public Utilities Board (PUB) restricts the supply to daylight
hours normally and to 6 to 7 hours a day approximately one-third of the
time, in order to enable water to reach all part of the system during
these hours. Pumping from the lenses, however, is maintained at a constant
rate all the time.
In the three most-populated areas (namely Betio, Bairiki, and
Bikenibeu), seawater reticulation systems have been constructed, since the
early 1980s, for flushing toilets and waste disposal through ocean
outfalls. This reserves the groundwater for other domestic use. No
treatment, other than the grinding of solids in the pumps, is provided for
wastewater before the sewage is discharged through the ocean outfalls.
The increasing population of South Tarawa is placing a great deal of
strain on the limited water resources available. In addition, the issue of
squatters living on the Water Reserves has not been resolved, and there
are already indications that the freshwater lenses are being polluted by
such development. Most of the suitable freshwater lenses in the vicinity
of South Tarawa have been utilised and any major expansion of the water
supply would involve either the development of lenses on North Tarawa,
such as on Abatao and Tabiteuea Islands, or other solutions, which would
increase water production costs. The current water tariff of $0.80/m3
is not sufficient to cover the operation and maintenance costs of $1.44/m3
incurred by PUB, even with some Government subsidy, and revenue collection
is incomplete and slow. There is a high percentage of unaccounted-for
water, estimated at 50%, of which perhaps 15% is due to physical losses
while the rest is due to unread water meters and illegal connections.
Notwithstanding, there is under-utilisation of rainwater at present, as
many houses and buildings do not have rainwater collection facilities;
many of those government and private houses that do have rain catchment
facilities have broken or blocked gutters and downpipes which render then
The performance of the South Tarawa water supply system is a fine
example of a fully-developed freshwater lens. During the 10 months drought
(1988-1989) and 1995, the lens suffered only marginal thinning effects.
The total land area of the Buota and Bonriki groundwater lenses is only a
little over 1 square kilometres (km2) and it is supplying over
1250 m3/day. The conductivity reading of the water supplied
towards the end of the drought never went above 600 FS/cm which is within
the WHO water-quality guidelines.
On Kiritimati Island (Figure 38), water is supplied from a combination
of groundwater extraction, collection, and distribution schemes; rainwater
collection schemes using a variety of storage tanks; and, privately-owned
or communal shallow dug wells. The estimated population of the island in
1995 was 3 095, but the island, which is the largest in Kiribati, features
high among that country=s priorities for development. A sustainable water
supply is critical for the potential future development of the island,
mainly as a tourist destination. Water supply systems exist at Decca
(supplying Ronton and the public buildings of Tabakea); Banana (supplying
the Main Camp, Banana, and the Fisheries building near Kiritimati
Airfield); the Captain Cook Hotel at Main Camp; and, Boran (Poland).
Figure 38. Map of Kiritimati Island.
The Ronton water supply system is in a poor state. The pipeline from the
galleries in Decca to the settlement at Ronton (which had a 1995
population of about 1 234) is leaking, with recent tests indicated a 20%
loss rate, and the quality of the abstracted water is not suitable for
drinking. Faecal coliform bacteria are present in the water and
conductivity exceeds 3 000 mS/cm. The overhead tank which feeds the Ronton
reticulation system is also leaking resulting in low water pressures in
the system. As a consequence, water is imported into Ronton by the water
tanker truck which transports water from the Banana and Decca water
reservoirs. However, only those people living in houses with a storage
tank enjoy the full advantage of the water tanker service. Very few houses
in Ronton have rainwater tanks. Tabakea (which had a 1995 population of
about 796) has no public water supply system, and freshwater is obtained
from shallow wells and a few rainwater tanks. This village is also served
by the water tanker truck, which most benefits those properties having
water storage tanks. Banana (which had a 1995 population of about 857) has
a water supply system, based on pumping from a gallery and a well north of
the village which was constructed during the late 1980s by the Ministry of
Line and Phoenix Development (MLPD), although, apparently, not in
accordance with the design proposed in a 1983 study. The system does not
provide a 24-hour supply, and, while the quality of the water has an
acceptable salinity level, the water is highly contaminated. The water
supply system is currently not operating very well and water is also
imported into this community by the water tanker truck. Boran (which had a
1995 population of about 208) has an old reticulation system, but new
galleries have been constructed close to the village by the MLPD. However,
the galleries are overpumped and the quality of the water is excessively
saline and bacteriologically contaminated.
Operation and Maintenance
Most of the technical problems encountered in the operation of the small
diaphragm pumps used for water abstraction from dug wells have been caused
by air entering the transmission mains through poorly-jointed pipes or
pipe damage. The handpump, itself, can last for more than five years if it
is properly maintained; the life span of the Southern Cross handpump (used
for infiltration gallery systems) can be ten years with proper
maintenance. Table 7 lists the parts of the handpump that need frequent
replacement. The Southern Cross handpumps are simple to maintain, and,
given available spare parts, breakdowns are minimal. At present, the
country relies on overseas supplies for spare parts, but there are plans
to set up a local industry to fabricate simple parts such as the plunger
rod and handle assemblies. The rubber diaphragm can be replaced with
rubber salvaged from tractor truck inner tubes. Based on experience, the
rubber diaphragms provided by pump manufacturers last for only three weeks
to three months, depending on the pump usage. Diaphragms made from tractor
truck inner tubes can last over six months.
The problems that can occur with solar pumps are breakage of the drive
belt that connects the motor pulley to the pump pulley (which can be fixed
with a new belt); malfunction of the maximum power point tracker (MPPT)
(the Mono pump can still work without it); wear on the rotor/stator; and,
failure of the pump cannot start on its own (usually due to tight spots on
the rotor/stator caused by the expansion of the rubber stator). Based on
field experience, these problems commonly occur after five years of
operation, although the drive belt can break after over two years. Repair
of the drive belt is very simple and can be done by the Island Council
Plumber (if a spare belt is available). The MPPT and the rotor/stator
failures cannot be fixed by the Island Council Plumber, although, if a
spare MPPT is available on the island, it can be replaced by the Island
Council Mechanic. With appropriate training, tools and spare parts, the
Island Council Plumber could also be enabled to replace the rotor/stator.
TABLE 7. Components of Handpump Requiring Frequent Replacement.
|Pump Part Description
||Frequency of Replacement
||Unit Cost of Part
||Three weeks - three months
|Bolts and Nuts for Hundle
|Bolts and Nuts for Pump Body
Level of Involvement
The technologies adopted are generally accepted by the communities.
Given the health-associated benefits of clean water, people are willing to
participate in the implementation of a project, and, with the completion
of water supply systems in some villages, people living in neighbouring
villages or islands can be motivated to request water supply systems or
work voluntarily to speed up the work. The water systems in the outer
islands are operated and maintained by the village people, and the Island
Council Plumber or Sanitary Aide, with readily available spare parts. Only
the case of solar pump breakdowns is technical assistance required from
the Public Works Division. Such problems, however, are rare within the
first five years of operation.
The capital, operation and maintenance cost of village water systems are
tabulated in Table 8 below.
TABLE 8. Capital, and Operation and Maintenance Cost of Village
||Per Capita Capita Cost
|Tamana-Type Hand Pump
aCapital cost includes the costs of all system components
(i.e., pipes, tanks, solar panels, pumps, etc.). For the hand-operated
diaphragm pumps, the capital cost was derived using the typical three
handpumps installation per transmission line.
It is clear that from Table 7 that the cheapest pumping option is the
Tamana-type handpump. However, the Tamana pump cannot be used in
reticulated potable water systems as it is only capable of drawing water
from wells within a 30 m radius of the house. The second cheapest option
is the solar pump system, but the capital cost is high. However, should
the (outer island) communities become involved at the grassroots level in
local fundraising, acquisition of such systems to improve community water
supply systems may be possible, and, in such situations, government
assistance in purchasing an appropriate type of system and adequate
quantities and selections of spare parts is available. Because of the
local sense of ownership that results from community funding, such systems
are usually very well maintained.
The availability of spare parts can be a problem, as many have to be
imported. The government presently assists with ordering spare parts from
overseas suppliers and resells them at a reasonable price to respective
island councils. However, in consultation with pump manufacturers in
Australia, the possibility of setting up a local industry to manufacture
simple spares for handpumps under license is being investigated as a means
of reducing the cost of spare parts. Until then, the government has set up
a revolving fund to finance maintenance of water supply systems in the
outer islands. The initial fund of $8 000 was established in 1995 to
purchase the most-needed spare parts for handpumps and solar pumps
installed during 1985. Also, the idea of setting up village water
committees to operate and maintain village water systems, and to collect
affordable water fees from the consumers, is being pursued to ensure the
sustainability of village water systems. Water fees would be collected
from village water consumers for maintenance, operation, and replacement
of water supply infrastructure at a proposed rate of $1.00 per household
per month for handpump users and $2.50 per household per month for solar
pump users. In urban areas, the water tariff is $0.80/m3.
Effectiveness of the Technology
The Southern Cross solar pumps were difficult to start when the
pumps were first installed in 1985. The pumps would not start
automatically in the morning before 0800, or in the afternoon after 1500
hours until sunset, or during cloudy periods of the day. This was resolved
by installing a power maximiser (controller) to boost the current from
solar panels to start the motor during these periods, and by placing a
spacer gasket at both ends of the rotor/stator to eliminate tight spots.
Such problems cannot occur with the Mono pumps as the Mono Solar pumps use
a larger horse power motor (i.e., 1 hp versus 1/3 hp, as shown in Table
6). The Mono pumps also can work without controllers, but they have
approximately 30% less pump output.
The Tamana pump may prove to be the best, most affordable and
maintainable means of pumping water from shallow hand-dug wells even
though the Tamana pump can only draw water efficiently from a distance of
not more than 30 m. While the use of the pumps reduces the risk of
transmitting diseases in comparison to the traditional method of dipping a
bucket into the well, the problem of contamination of hand-dug wells from
pit latrines located in close proximity to the wells remains. This problem
can be minimised to a degree by using community-based infiltration
galleries, which can be located at some distance from the village centre,
and which draw water from the surface of a freshwater lens. However, there
is a need for low cost, low discharge handpumps, distributed over fragile
freshwater lenses, which are environmentally preferable to having many
wells used at low intensities spread over the lens, to effectively skim
the aquifer, drawing off the highest quality water and minimising saline
From operational experience, the best pumping systems for use in
Kiribati are the Mono-type solar pump and Southern Cross type
hand-operated diaphragm pump. The Tamana-type hand pump should be used for
sanitary purposes only. The Southern Cross handpumps draw small volumes of
water from distances of up to 750 m over a 7 m lift head. Where the good
water sources are located more than 750 m away from habitations, or where
a greater head exists, solar pumps should be selected. These pumps are
used to pump water from infiltration galleries into elevated storage tanks
or reservoirs. These pumps typically have a minimum design flow of 0.8 l/s
when operated on a 6 to 8 hour pumping day over a total head of 20 m
maximum. The pedestal horizontal type helical rotor pump is the most
suitable type of this pump.
Infiltration gallery systems reduce the risk of up-coning of the
underlying seawater. However, these systems require the use of pumps.
Present experiences with the small diaphragm pumps indicate that such
pumps are reliable and relatively easy to maintain: the diaphragm, made of
plain rubber, can readily be replaced by the village plumber by unscrewing
four bolts on the pump body. However, because of their limited pumping
range, solar pumps are often used. Solar pumps have no fuel costs and
limited operation and maintenance requirements.
Open, hand-dug wells have the obvious drawback of being a potential
health hazard, as the well water is exposed to contamination. In addition,
the villagers tend to dig these wells close to their dwellings, where pigs
and other domestic animals move about and could potentially foul the
exposed water. Moreover, the proximity of pit latrines (first introduced
in the 1970s) to the hand-dug wells is causing many wells to become unsafe
for drinking. In high-density housing areas, such as South Tarawa, the
remaining, old, open dug wells are now a severe health hazard, and even
though covered dug wells are well protected, recent tests on the water
quality of these protected wells have proven positive for the presence of
faecal coliform bacteria. Open galleries or collection trenches also are
open to contamination in the same manner as the dug wells.
In Kiribati, water collection is not the sole responsibility of women as
it is in other countries in Asia and Africa, and some countries in Latin
America. The people in Kiribati tend to live in places where good
groundwater exists and water collection from distant wells is done
collectively by the members of the community and households who can walk
long distances. The traditional method of obtaining drinking water is
simply to bail water out of an open, hand dug well using any type of
container that could be tied at the end of a string (rope). Similarly the
traditional method of defecating is to use the beach or the bush. The
introduction of piped water supply systems, and water-sealed latrines or
flush toilets especially in the outer islands, are imported ideas which
are not well received by the people. Nevertheless, the problem with the
use of the traditional methods of obtaining water is that open hand-dug
wells are often located dangerously close to pit latrines and other
sources of contamination in the village. An high incidence of
water-related diseases (mainly diarrhoea) in recent years can be
attributed to the fact that many people still use shallow, open, hand-dug
wells contaminated by nearby leaking toilets, pipes, and fixtures, or
nearby soak-away pits. With the problem of high incidence of water-related
diseases, the people are now beginning to appreciate the health-associated
benefits of piped water supply and proper sanitation.
Notwithstanding, the implementation of water projects in the outer
islands of Kiribati require much patient and time-consuming groundwork
before successful implementation is achieved. This is because community
consensus and participation are not easy to achieve, despite the fact that
water projects are often initiated by the community. The main reason for
community reluctance to participate is due to the facts that they are
expected to provide free labour as their contribution to the project, and
that they are very busy with the routine chores everyday. Land disputes
over the siting of wells, galleries, or tanks can also cause delays in the
implementation of a project. Land in Kiribati is traditionally owned by
individuals and the landowner consent is required before the land is
utilised for the benefit of the community. If the landowner does not agree
to surrender the land for use by the community, then government can
exercise power under the Land Acquisition Act to acquire the piece of land
for public use, but such powers can only be used after all diplomatic
means of negotiation fail. Lands acquired by the government under the Land
Acquisition Act may be subject to vandalism, and the former landowners may
continue to occupy the water reserve areas. Nevertheless, there have been
cases where people living on water reserve areas in Kiribati were removed
In addition, problems between upstream and downstream water consumers is
universal and Kiribati, with its low-lying islands, is no exception.
However, this problem only occurs with solar-powered pumping systems.
People living at the upstream end of the rising main tend to misuse the
water by keeping their taps on, resulting in low water pressures or no
water at the downstream taps. This problem can result in downstream water
consumers ransacking the water system.
Further Development of the Technology
Due to the pressing problem of land scarcity, the government is keen to
explore alternative water sources to meet water demands on South Tarawa,
the capital of Kiribati. Alternative water sources being considered
include desalination, reclamation of depressed areas for water harvesting,
and establishment of rainwater catchments. There are several types of
desalination plants available on the market and Kiribati has to choose the
most appropriate type. In contrast, water harvesting by reclaiming
low-depression areas on Tarawa, of about 350 ha in areal extent, so as to
form a freshwater lens, could yield approximately 2 600 m3/d,
while the use of rainwater by individuals and institutions to alleviate
the water shortages is to be promoted. Currently, the use of rainwater
systems is not widespread, and, in spite of existing regulations, many
existing roof collection installations are inoperable or under-utilised.
There is a need to design rainwater catchment systems for particular roof
areas of adequate size to sustain a long drought. This is an expensive
option as it will involve constructing huge-volume tanks. The costs of
these three alternatives has been estimated to be in the range of $1.6
million to $24 million, based on preliminary costings. However, it must be
noted that there can be no life without water.
The experience gained by Kiribati in augmenting and maximising fresh
groundwater resources is unique to a low-lying coral islands situation.
The technologies used so far have been tested for quite a number of years
and have been proved to be working well. The best type of pump for use in
the country is the positive displacement pump, as the pumping rate can be
optimised to minimise salt water intrusion. For centralised water supply
systems with distribution tanks and communal taps, the best type of pump
is the Mono pump. For handpump systems, the best pump is the Southern
Cross hand-operated diaphragm pump, although another type of pump that
should be promoted for sanitary purposes, especially in the outer islands
and peri-urban areas, is the Tamana pump. The performance of the Tarawa
Water Supply scheme, which at present is serving more than 26 000 people,
is an exemplary case of a fully-developed groundwater lens. The use of
properly-constructed infiltration galleries and the use of positive
displacement pumps is an effective groundwater extraction method with
minimal thinning effect on the freshwater lens. The lens area is just over
1 km2 with a total water production rate of 1 250 m3/d.
The conductivity reading of the water never exceeded 600 FS/cm, even
during a 10 month long drought. A significant factor in the success of
this project was the recognition and inclusion of social and cultural
consideration at the inception stage and during the implementation stage
of the project.
Despite these successes, there is a need to improve the design of the
Southern Cross handpump so that it has a longer useful life. There is also
a need to try other types of pumps available on the market to determine
their suitability for use on low-lying coral islands. It is also important
to promote public awareness of the health-associated benefits of clean
water, water conservation, and well location within the community. This
could be done using radio advertisements, posters displayed in public
places, inclusion of appropriate teaching materials in the primary schools
curriculum, and through meetings and workshops held in the village maneaba
(traditional meeting hall). The public awareness campaign should be an
on-going activity. Further, in order to fully utilise rainwater, all
buildings with permanent roofing should have a rainwater catchment system.
This should be done to an appropriate engineering design, promoted through
the public awareness campaign, and included in enforceable legislation. It
is very important that the design of the rainwater system be adequate to
sustain supply during prolonged drought periods.
Taboia Metutera, Public Works Division, Government of
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Kiribati - Tarawa Water Resources Pre-Design Study. Australian Department
of Housing and Construction, Canberra.
Australian Government Department of Housing and Construction 1986.
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Engineering Branch Report No. OS 236, Australian Department of Housing and
Burke, J. 1995. Mission Report No. KIR/93/001 - Kiribati and Fiji.
United Nations Department of Development Support and Management Services,
United Nations Development Programme, New York.
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Falkland, A.C. 1983. Christmas Island (Kiritimati) Water Resources
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Project No. KIR/87/C02, UNDP, New York.
National Planning Office 1992. Kiribati 7th National Development Plan
1992-1995. Ministry of Finance and Economic Planning, Kiribati.
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Richards and Dumbleton International, Consulting Engineers 1978. Water
Resources Tarawa, Feasibility Study. Richards and Dumbleton International,
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Development] 1989. Water Assessment and Development, Pacific Islands,
Inception Report. United Nations Development Programme, New York.
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1992. Water Resources Management Techniques for Small Islands. Report No.
INT-88-R41, United Nations, New York
van Putten, F. 1989. The Viability of Groundwater Development on the
Outer Islets of the Tarawa Atoll. Project No. RAS/87/009, United Nations
Development Programme, Suva.