2O5.288 PR

Problems Of Rural Water SuppliesIn A Developing Economy: Case Studies OfAnambra and Imo States of Nigeria

by Kalu O. LimaDepartment of Geology,University of Nigeria,Nsukka, NigeriaandBoniface C. E. Egboka,Department of Geological Sciences,Anambra State University of Technology.Enusu, Niseria

r, ' I ' -^NATIONAL REFEREi-:C'£!-OR COMMUNITY WATSR SUPPLY ANDS.'--.A<!TAriON

ABSTRACT

Over 15% of the population of Anambra and Imo States live in rural communities and this is projected to remainso until the end of the century. Most of these rural communities do not have modern water facilities. They dependon traditional sources that are generally of questionable quality, insufficient quantity and often liable to seasonalfailures. Waterborne diseases, sometimes in an acute form, are therefore endemic in many of the rural areas. Inorder to solve this problem, a reliable and consistent low cost water supply scheme based on the available waterresources in the communities must be designed and constructed. In this study three types of such schemes are de-veloped. The first uses rainwater, the second, surface water, and the third relies on ground water. Areas whereeach of these schemes may be developed have been indicated. Comparative cost analysis indicates that schemesusing ground water have a cost advantage over those using rainwater or surface water. It also shows that boreholesequipped with handpumps or improved/sanitary wells are more economic than those with motorized pumps for ruralpopulations of less than 2,000 inhabitants.

INTRODUCTION

The bulk of the population of Anambra and ImoStates, comprising most of the rural communities, de-pends on supplies of water sources that may be faror near, of questionable quality, insufficient quantityand that may often be liable to seasonal failures. Wa-terborne diseases, sometimes in an acute form, aretherefore endemic in many of the rural areas.

These disturbing factors of poor and inadequate wa-ter supplies and other features of underdevelopmenthave attracted the attention of successive governments.The present state and federal governments lay strongemphasis on rural development. Hence, rural devel-opment ranks high in national planning and develop-ment programmes. A Directorate of Rural Develop-ment has been created to design and construct devel-opment projects at the rural level. This Directorateis supposed to take over some of the functions of theRiver Basin Authorities which performed these dutiesin the past. However, although rural roads and elec-tricity projects have been initiated and pursued withvigour by national and state governments as well as

Rural development rankshigh in national planning anddevelopment programmes.

private agencies, one has yet to see a consistent ruralwater scheme or any organized and long-term plannedwater resources programme. The emphasis so far ison programmes for urban areas.

This paper critically assesses the alternative watersupply schemes that could be embarked upon in ruralareas, and discusses the relative social and economicadvantage of each of these schemes. The primary ob-jective is to aid water resources planners in develop-ing a basic framework from which to select approp-riate and consistent water schemes for the rural com-munities in Imo and Anambra states in particular andNigeria in general.

0250-8060/88/S3.30 Water International, 13 (1988) 33-45

S T U D Y A R E A

O 125 25O km

Figure 1. Location map of studied area (insert shows the location of Nigeria in the African Continent).

DEFINITION AND DISTRIBUTION OFRURAL COMMUNITIES IN ANAMBRAAND IMO STATESi

The definition of rural communities varies fromcountry to country. In some developing countries whatconstitutes a rural community often varies from onegovernment to the other. Generally, the principal fac-tors considered are the economic activities and pop-ulation of the communities. According to a United Na-tions demographic Year book for 1970, rural com-munities have population ranging from less than 500to about 30,000. The predominant economic activi-ties in these communities are production of food andraw materials. In this study, rural communities havebeen taken as those with populations less than 20,000and whose inhabitants are mostly peasant farmers and

fishermen. Such people are usually not expected tosupport social services on an economically viablebasis.

There are more than 2,000 rural villages scatteredthroughout Anambra and Imo States. Figure 1 showsthe location of these states in Nigeria and the AfricanContinent and Fig. 2 shows the approximate areal dis-tribution of the more populous rural communities(.> 5,000 inhabitants) in Imo and Anambra states. Thesmaller ones could not be located due to the scale ofthe map used. The population of the communities inImo State is given in Table 1. The figures are basedon the 1963 census and an annual growth rate of 2.5 %.For immediate planning purposes, projections for theyear 1990 are of greatest importance. The table showsthat over 85 % of the Imo State population of about5.6 millions live in rural communities and this is pro-

34 Wafer International

Ez.amgbo

• Abakaliki

' 7 '̂ S—-Ihiaia // • /•/ Orlu

i»'./sL • j —^Nkwerre•Mgbidt

•Umuefemei

• Etiti

• T o w n s• Urban communities

( 2O,OOO people)

• Large Rural communities< 5,000-20,000 people)

Okpuala-f *Ngwa

Railway line

•—— State boundary

Figure 2. Distribution of rural and urban communities in Anambra and Itno States.

Vol. 13, No. 1 (1988) 35

jected to remain approximately so till the end of thecentury. Population for Anambra State is similar tothat of Imo State.Table 1: Community population in Imo State

CommunityPopulation

20,000(Percentage)

10,000-20.000(Percentage)

2.000-10.000(Percentage)

2.000(Percentage)

Total

Number of Communities

1985

39(3.45)

148(13.07)

385(34.01)

560(49.47)

1.132

1990

45(3.98)

155(13.69)

391(34.54)

541(47.79)

1.132

Total Population

1985

830.000(14.72)

1 .650,000(29.26)

2,452.800(43.49)

707.200(12.54)

5,640,000

1990

957.600(15.0)

1,955.000(30.64)

2,773.000(43.46)

695,542(10.91)

6.381,142

PHYSIOGRAPHY AND GEOLOGY

Two major cuestas characterise the regional reliefof Imo and Anambra States. The first is the N-S trend-ing Ukehe-Enugu Okigwe-Arochukwu cuesta whilethe second is the more subdued NW-SE trendingAbagana-Okigwe cuesta. The two cuestas intersect atOkigwe and generally rise to about 330m above sealevel and 150 to 200m above the surrounding plains.The terrain between these major relief features com-prises dissected ridges and isolated hills. Generallythe landscape rises gradually from the south (Aba) to-ward the north (Nsukka).

The two major relief features outlined above con-trol the drainage in the two states. Three main riversystems, the Niger, to the west, Cross River to the eastand Imo River to the south, drain the area. The wa-tershed between these river systems is an inverted Y-shaped figure corresponding to the crests of the twointersecting cuestas. The drainage in the area containedin the obtuse angle between the stem and the westernarm of the inverted Y goes to the Niger while that with-in the obtuse angle to the east is to the Cross River.The area between th& intersecting arms encloses thedrainage basin of the Imo River [1].

Anambra and Imo States are underlain by a sequenceof sedimentary rocks intruded in some parts by dol-erite and more basic rocks. Figure 3 shows the sur-face distribution of the geologic formations in the area.The rock formations generally fall into 2 groups; theCretaceous and Tertiary formations. The Cretaceousformations comprise the Asu River Group (Albian andthe oldest sedimentary formation in the area), Eze-Aku Formation (Turanian), Awgu Shale (L. Senon-ian), Nkporo Formation (Cenomanian), Mamu For-mation (L. Maestrichtian), Ajali Sandstone (M. Mae-strichtian) and Nsukka Formation (Upper Maestrich-

tian). These formations are composed mostly of shales,argillaceous sandstones, limestones and thin coalseams. The Asu River Group and Eze-Aku Forma-tion are intruded into by dolerite sills and dykes andthis has given rise to intense fracturing of rock unitsof these formations especially in the vicinity of theintrusions. The Ajali Sandstone is the only dominantsandy formation within the Cretaceous group and hasbeen extensively tapped by water wells.

The Tertiary formations include the Imo shale(Paleocene), Ameki Formation (Eocene), Ogwashi/-Asaba Formation (Oligocene to Miocene) and the Be-nin Formation (Miocene to Recent). The Imo Shaleis dominantly argillaceous, the Ameki Formation ismade up of intercalations of shale and argillaceoussandstones while the Ogwashi/Asaba and Benin For-mations are dominantly sandy sometimes with morethan 80% of sandstone units. The outcop of areas ofthe Ogwashi/Asaba and Benin Formations are inten-sively penetrated by water wells.

RURAL WATER SCHEMES

Rural Water Supply Schemes are those that are de-signed to supply water to the rural communities. Thereare three main types of water supply schemes that maybe developed for any community whether urban orrural. These are rainwater interception scheme, sur-face water scheme and ground-water schemes. Theselection of any of these schemes for a particular areadepends on the type of water resources available inthat area and the relative cost of developing the re-sources (i.e. the unit cost per user of water).

Rainwater interception scheme involves the inter-ception and storage of rainwater for use during thedry months. This scheme may be economic for in-dividual households but the design and constructionof interceptor networks that can serve small commu-nities is rigorous and costly. Even where individualhouseholds are provided with storage tanks, it maybe difficult to operate the rainfall scheme at a suffi-cient sanitary level.

The surface water scheme involves the impound-ment of streams and rivers or direct extraction of wa-ter from big rivers, freshwater lakes and oceans andthe treatment of the water to remove objectionable con-stituents. The marked difference in the initial costsof developing large surface water schemes relative toground water (as would be established later) makes thescheme unattractive for rural communities. Sometimesit is possible to persuade communities to use local la-bour to construct relatively cheap impoundment struc-tures on small permanent streams at close proximityto the communities. This could make such surfaceschemes attractive economically. Also the availabil-ity of the surface water resource is known at all times

36 Water International

Asu River Group

Eze-Aku Formation

Awgu Formation

Nkporo Formation

Ajal i Sandstone

Nsukka Formation

I mo Formation

Ameki Formation

Ogwashi-Asaba FormationBenin Formation

AI luvium

Scale: I : 1,000,000

Figure 3. Geologic map of Anambra and Imo States.

Vol. 13, No. 1 (1988) 37

and its handling is almost permanently under control.These advantages often outweigh the cost disadvant-age especially for large s le water supplies to urbanareas or for irrigation purposes.

The ground-water scheme comprises schemes inwhich the supply source is ground water. It may bedivided into pipe-borne system and non-pipe-bornesystem. The pipe-borne system uses a distribution net-work of pipes to reach the individual users whereasthe non-pipe-borne system supplies directly to the us-ers without any distribution network.

Pipe-borne water supply systems based on groundwater are developed either for individual communi-ties or for a number of communities under one supplyarea. Such a system comprises one or more boreholes(8 to 10 inches diameter) with electric submersiblepumps or diesel driven reciprocating pump and an ap-propriate distribution network that serves the com-munity through public standpipes. There may how-ever be a few households which would have directconnections. The practice of connecting householdsdirectly from the central network is good for publichealth considerations and it also facilitates water rev-enue collection.

The U.N.O. recommended minimum amount of wa-ter necessary to maintain life is about 200 liters percapita per day. However for the rural communitiesin Nigeria, 100 liters is enough to cover the needs ofan individual, including the requirements of the smallanimals raised by the household. Depending on thecharacteristics of the target aquifer, a borehole withmotorized pump can yield 20m3hr' to over 100m3hr'in Anambra and Imo States. Assuming a borehole isoperated for 8 hours daily (8 hours is the daily work-ing period in Nigeria) a borehole can thus supply wa-ter to at least 1600 people. Communities of this sizeor more should therefore be the target for the pipe-'borne schemes based on ground water.

There are three main types of non-pipe-borne sys-tems that characterize ground-water development. Thefirst consists of boreholes equipped with hand operatedpumps or windmills. These boreholes are preferablylocated in close vicinity to the villages and it is de-sirable to provide at least one borehole for every 300persons to avoid overcrowding at each water point.Such boreholes are particularly appropriate for thesmall villages with populations less than 2,000 whichare spread over large areas of Anambra and Imo

It is desirable to provide atleast one borehole for every300 persons

States. Since the boreholes are drilled essentially forhandpump operation, their diameter is restricted to15cm (6 inches) and they usually only partially pen-etrate the full thickness of the aquifer. The averageyield of hand pumps is only about 0.5 to 1.5m3hr'and mostly depends on the depth to the ground-waterlevel. Thus low permeable materials such as clayeysands, sandy clays, sand/shale intercalations as wellas high permeable materials may be used as aquifers.The drawdown associated with hand pumps is also lowbecause of the low and discontinuous yield. The onlyhydraulic requirement is that the static water level inthe wells should not be more than 70m [2] to alloweasy lifting of water to the surface.

The second type of non-pipe-borne system is thehand-dug well [3]. This type of well is traditional andhas been used in various parts of Nigeria for manyyears. It is constructed with hand tools and may belined with concrete tubes. Such wells are generallyshallower than boreholes and are sometimes coveredand equipped with small pumps. More usually, theyare left open and a bucket is used to raise water tothe surface. They therefore present a pollution haz-ard. Owing to their shallow depths and the fact thatthey only partially penetrate the aquifer, they are af-fected by seasonal fluctuations of the water table andhence may dry up in the long dry season. The sanitarylevel of hand-dug wells can be improved by liningthem with concrete rings. Shallow pumps with suc-tion lifts may be used to lift the water. Such suction-lift pumps are located on the surface and are there-fore easy to operate and maintain and would also avoidthe subsequent pollution of the water resource.

They are left open and . . .therefore present a pollutionhazard.

38

The third type of non-pipe supply is developed onsprings by constructing a head box and storage tank.Most springs are perennial and the water is clear, re-quiring no treatment. The supply is by gravity flow.Such systems are the most economical to run becauseoperational and maintenance costs are minimal.

The water supply schemes discussed above consti-tute the modern water supply schemes. Before the in-troduction of these systems, communities got their wa-ter by fetching directly from nearby streams, springsand ponds or by storing rainwater. These earlier meth-ods constitute the traditional water supply systems.

Water International

WATER RESOURCES POTENTIALS OFANAMBRA AND IMO STATES

The types of water supply schemes that may be de-veloped for rural communities have been outlined inthe preceeding section. The selection of any of theseschemes depends on the type of water resources avail-able in an area and in places where more than oneresource is available, on the relative unit cost of de-veloping each resource. This section establishes thewater resources of the study area and outlines theavailable resources for each area.

In terms of water resources, Anambra and ImoStates may be divided into 5 Zones as shown in Fig.4. Zone 1 extends from Abakaliki westwards to Enu-gu and from Ikem (Anambra) Southwards to NguzuEdda (Imo). The zone is underlain by middle Creta-ceous sandstones, fractured shales, limestones andscattered pyroclastics and intrusives. Generally thesandstone units are thin (less than 20m), fairly wellcompacted and have low permeability except at somelocalities where fracture porosity occurs. Location ofprolific aquifers in this zone would involve elaborategeophysical investigations and is costly. The chancesof success are also slim. However the near surfacesandstones and fractured shales yield sufficient waterto hand-dug wells and shallow boreholes with hand-pump as evidenced by the high success rate of theUNICEF rural water supply schemes in parts of theZone using Indian Mark II handpumps. Only a fewpermanent springs occur in this zone and most of thestreams have very low dry season flow. In additionthe streams are frequently located at places very far(sometimes 5km or more) from the users or are underinaccessible conditions such as at the toes of steep hills.Although the streams could be impounded cheaply us-ing direct labour, the water from them will reach theusers only after long trekking to the supply point. Theonly practicable surface water scheme is stored floodwater. This is expensive for small rural communities.The only possible water supply schemes to the ruralcommunities in this zone are rainfall interception,shallow handpumped boreholes and improved/sanitaryhand-dug wells.

Zone 2 is underlain by the Ajali Formation and ex-tends from Nsukka (Anambra) to Arochukwu (Imo).The zone contains very prolific aquifers. The aver-age yield of boreholes is over 50m3 hr1 and the hy-draulic conductivity ranges from 0.36m hr1 to 36.0mhr1. Extensive well fields with motorized pumps canbe developed. However the average depth to theground water is more than 60m below the surface andschemes using shallow boreholes with handpumps orimproved hand-dug wells may not be successful.Springs are rare but where they occur, the,y are usu-ally perennial. Developable streams or rivers are alsorare. The only practicable water supply schemes are

those that use deep boreholes with motorized pumps.The small rural communities in this zone should there-fore be combined to form a supply area or be con-nected to the distribution grid of nearby urban areas.

Zone 3 comprises areas underlain by the Nsukkaand Ameki Formations and sandstone members of theImo Formation. Promising confined aquifer systemsoccur at depths ranging from 60m to 20m below thesurface. The yield of boreholes is variable with an av-erage of about 30m3 hr1 and hydraulic conductivitiesrange from O.lm hr1 to about 7.0m hr1. Numerousisolated unconfined aquifers occur at the outcrop ofthe several sandy units of the formations. The depth tothe water table in these aquifers is generally less than20m below the surface. However, the saturated thick-nesses of the unconfined aquifers are variable andmany rope wells completed in this zone are seasonal.Numerous springs occur and many of them areperennial.

Almost all the schemes using rainwater, surface wa-ter and ground water may be developed for commu-nities in Zone 3. However, more detailed hydrologicand hydrogeologic investigations are needed to estab-lish the specific relative abundance of the resourcesin each community. This would enable more approp-riate and reliable schemes to be selected for each ofthe communities in this zone.

Zone 4 is underlain by the Imo Formation. The for-mation is made up of thick clay-shale units, sandy claysand minor clayey sand units. Borehole records indi-cate a high failure rate of boreholes completed in thiszone. However at some localities, high yielding arte-sian aquifers have been encountered at depths below200m of the surface. A number of perennial streamsand some seasonal springs also occur in this zone. Wa-ter supply schemes using deep boreholes with mot-orized pumps may be costly to drill, operate and main-tain. Shallow boreholes with handpumps or improvedrope wells may not work in this zone. The only eco-nomic schemes are those using rainwater or streamsources.

Zone 5 coveres the extreme West and South of theStates. It comprises areas underlain by the Ogwashi/A-saba and Benin Fromation and the Quaternary alluv-ium of the River Niger Plains. Deep unconfined aquif-ers generally occur in this zone and the water tableis everywhere less than 50m below the surface. Theaverage well yield is over 50m3 hr1, but the hydraul-ic conductivity values vary extensively, especiallywithin the areas underlain by the alluvium. The springsand streams are mostly perennial and suffer little fluc-tuation in discharge throughout the year. Water sup-ply schemes using rainwater, surface water or groundwater may be developed for any rural community inthis zone. The choice of an appropriate scheme is,however, dependent on the unit cost of developingeach of the schemes. The next section outlines the

Vol. 13, No. 1 (1988) 39

Onitsha \ - 3 • >

• Atani

Umuogwo* •Imeabiam o/«Okpuala-£. _ _. . _

•v,

Figure 4. Water resources potential map of Anarnbra and Imo States.

40 Water International

Jcomparative cost of developing ground-water and sur-face water resources and established a scale of pref-erence in the choice of an optimal water supply schemefor any rural area.

COMPARATIVE ADVANTAGE OF GROUND-WATER AND SURFACE WATER SCHEMES

Studies have shown that ground water has severaladvantages over surface water. It is usually less ex-pensive to develop than surface water and can be eas-ily expanded at a future date by the addition of newboreholes. Ground water is also generally physicallyand chemically pure and is more likely to be free ofpathogenic bacteria. Frequently, ground water hasbeen supplied directly to users without any form oftreatment. Where the quality of ground water is ob-jectionable, the cost of treatment is usually low com-pared to the corresponding surface water treatment.

Ground water has severaladvantages over surfacewater.

Table 2: Comparative cost or developing surface water and groundwater to a community of 20.000 people at 200 liters per capita perday (as of 31 Dec. 1982).

A. SURFACE WATERItem Rate (#)

"Intake structure 100.000-200.000•Treatment work 130 per m'

ReservoirPowerPipelinesPumping House

same as forGround water

Cost iff)150.000520.000

Total 670.000

B. GROUND WATERi. -t- Drilling, casing 60.000 per

Screening, Development 150m deepand Pumping test borehole 240.000

ii. + Installation of pump.riser, mains, outle!elbow etc. 25.000 100.000

iii. Reservoiriv. Power source Same as forv. Pipelines surface water

vi. Pumping HouseTotal #340.000

•Figure from Enplan 4••Figure from Balasha-Jalon 5

+ Figures from Federal Department of Water Resources. Enugu.

Table 2 gives the comparative cost estimate of de-veloping surface water and ground water to a ruralcommunity of about 20,000. The water requirementof the community is taken as the U.N.O. recommend-ed value of 200 liters per capita per day and the totalwater needed is thus 4,000m3 day1 (4 million litresday1). It is assumed that this volume of water shallbe abstracted either from a river or from four bore-holes producing at an average rate of 45m3 hr1. Es-timates of the unit cost were taken from the reportsof 2 consulting engineers [4, 5] to Imo State WaterCorporation and 1982 borehole drilling reports of con-tractors to the Federal Department of Water Resour-ces, Enugu, Nigeria. It can be observed from the ta-ble, that although the estimates for the surface watersource were made at least two years before those forground water, the cost of developing the 4,000m3

day1 of water from surface sources is about twicethat from ground-water source. The cost differencearises mainly from surface water treatment work.However the unit cost of treatment usually decreaseswith increase in the treatment plant capacity and it islikely that at greater water demand, the cost differ-ence for the two sources will diminish. The cost es-timates given in Table 2 does not include variable costssuch as pumping and maintenance costs. The currentaverage cost of pumping water from a borehole isabout twenty Naira (#20.00) per hour and for 4 bor-

eholes operated at about 24 hours daily, the total costis AH92.00. The major maintenance work needed tokeep a borehole working in Nigeria is the repair ofthe submersible pumps which sometimes fall into theborehole. Such repairs are commonly done twice ayear per borehole at a cost of about N500. This gives#4000.00 for the four boreholes annually. These var-iable costs when added to the initial cost of develop-ing ground water would certainly make a lot of dif-ference. However the major economic defect of thesurface scheme is the high initial cost needed to de-velop it (as demonstrated in Table 2). This makes itunattractive for rural communities especially those thatare less than 5,000 in population. For urban waterschemes (involving more than 20,000 people) the sur-face water scheme is often a better alternative.

Studies made in Ghana [6] for the various types ofsupplies, namely boreholes with handpumps, mech-anized boreholes, and surface water systems are givenin Figure 5. The study was made in 1975 (eleven yearsago) and the absolute costs now would certainly havechanged. However, it is reasonable to expect that therelative costs would have the same trend. The figureshows that for communities less than 20,000, the unitcost for a surface water scheme is more than twicethat for a ground-water scheme. In addition, it alsoshows that boreholes equipped with handpumps havea cost advantage over mechanised borehole systemswithin the lower population range (less than 2,000).

Vol. 13, No. 1 (1988) 41

10,000 2O,000 30,000

Population of Community

40.0OO

1 . Surface water systems2. Mechanized borehole system3. Borehole with handpump

Figure 5. Comparative cost of developing surface water mechanised borehole and borehole with handpump [6].

In addition, boreholes can be drilled close to thetowns they serve, whereas the intake structures forsurface water treatment are, on the average, about 3kmfrom the sites of the treatment plants. The cost oftransporting the raw water may sometimes amount tothousands of Naira or even fractions of a million Naira.For example at the current cost of about #65.00 permeter of the relatively cheap asbestos cement pipe-line (8 inches diameter), a 2km long pipe will cost

about N130.000. This transportation cost may beenough to develop new well fields. The marked dif-ference in the initial costs of the alternative systemsproves the economy of the ground-water source andsupply. It is clear therefore that a ground-water schemeshould be preferred for rural communities whereverground water can be found in sufficient quantities andwith acceptable quality.

42 Water International

EXISTING WATER SUPPLY SCHEMES

Table 3 shows the distribution of existing water sup-ply schemes in the rural communities of Anambra andImo States based on inventories taken by Uma [7].Almost all the communities with populations more than20,000 (urban communities) have water schemes inImo State. The corresponding percentage for Anam-bra State is 52.0. For communities with populationsbetween 2,000 and 10,000, about 27% of them in Imoand 37 in Anambra have water supply schemes. Al-most all communities with population less than 2,000in Anambra State do not have any water scheme. InImo State where the UNICEF rural water scheme ex-ists, about 24% of the small communities (less than2,000 inhabitants) have water schemes. On the av-erage only about 30% of communities in Anambra and38% of communities in Imo State have water supplyfacilities while the rest do not.

Table 3: Distribution of Existing Water Supply Facilities In RuralCommunities of Anambra and Imo States (Data from Inventor)- Takenby Uma [7]). \

CommunityPopulation

20,000

10,000-20,000(Rural)2,000-10,0002,000(Rural)

No. ofCommunities

AnambraState

2898

253827

ImoStale

39148

385560

No. ofCommunitieswith WaterAnambra

State2551

9320

ImoState

3492

102137

Percentages ofCommunitieswith WaterAnambra

State89.352.0

36.82.4

ImoState87.262.2

26.524.5

Average percentage of Rural Communitieswith water 30.4 37.7

The water supply schemes for the more populouscommunities is through boreholes with motorisedpumps. The smaller villages are either connected tothe grid of the nearby bigger communities or are com-bined to form a supply area. Communities under theUNICEF rural water scheme have boreholes withhandpumps. A small number of schemes using springsources exist in some communities. Inventories onsuch schemes were not taken and they are not includ-ed in the table. Comparing Table 3 and the commu-nity population distributions, in Table 1, it is clear thatmost of the rural communities do not have modernwater supply facilities. They therefore depend solelyon the traditional systems which are insufficient bothin quantity and quality.

DISCUSSION AND CONCLUSIONS tIt is apparent from the foregoing sections that two

types of water supply problems exist in the rural areas.

Most of the ruralcommunities do not havemodern water supplyfacilities. They . . . dependsolely on the traditionalsystems

The first concerns the reliability and/or adequacy ofthe existing systems and the second is the absence ofany supply scheme in most of the small scatteredvillages.

An inventory taken in 1983 [7] indicated that of themore than 250 boreholes drilled in Imo and AnambraStates only 42 percent are in use; 38 percent are eith-er abandoned or in disuse while the rest are not yetcommissioned. Table 4 gives a clearer impression ofthe actual situation in some of the rural and urban wa-ter well fields. In some of the well fields, the numberof boreholes in disuse outnumbers the number in use.Generally the most frequent mode of failure is the col-lapse of the pumping units and the burning of the pumpmotor. These are as a result of poor well design andpoor maintenance. Although prolific aquifers occur,most of the wells partially penetrate the aquifers andin some, the screened sections of the wells are lessthan 25 percent of the saturated aquifer thickness.Drawdowns are thus high for relative small pumpingrate and time, especially in the vicinity of the pump-

Table 4: Operational condition of some well fields in Anambra andImo Stales (As of Dec., 1983).

Borehole

*Nine Mile Corner(Old pumping

station)*Nsukka Urban

UNN (Nsukka)Ohodo

"Onitsha•Nnewi

NnobiEke-NguruEnyieogugu-Mbaisc

*Umuna-OrluEziama-NkwereUmuahiaOhafiaArochukwuMbutuNenuOrie-Mbieri

State

Anambra

•••••••••

Imo

-•••••••••-

No. ofbore-holes

drilled

55

1053

11523464943434

Operational Condition

Commissioned

In-Use44

4216211

21411121

Aban-doned

11

6315311242522312

Not Com-missioned

——

———___12

1_1

———1

•Urban Scheme

Vol. 13, No. 1 (1988) 43

Iing wells. Because the wells were not properly testedbefore production started, and also because the waterlevels in the pumping wells are not monitored, crit-ical drawdowns can not be forecasted and prevented.Frequently, therefore, the water levels go below thesubmerged pumps and the motor burns off. The welldesigns should follow standard procedures and com-pleted wells should be properly tested to estimate op-timum production. Provisions for such tests are in-corporated in most existing job orders given to con-tractors and would be carried at no additional cost tothe water agencies. The major problem is the lack ofeffective supervision to ensure that the activities list-ed in the job orders are performed to specifications.

HydrochemicaJ analysis of some ground-water sam-ples [8, 9] indicate moderate to high acidity (pH =6.5 to 4.9), high free carbon dioxide (CO2) and thuscorrosion hazards. The boreholes in such areas shouldbe regularly maintained and the frequency of main-tenance should depend on the production history ofthe boreholes. This has not been the case in the statesstudied; rather rehabilitation is carried out only afterfailure has occurred.

An additional problem is insufficient and inconsis-tent energy supplies to the rural pumping stations. Fuelis supplied from a central point located at the stateheadquarters. While stations close to the headquartersmay receive their allocations in timely fashion, oth-ers farther away may have to wait for days and some-times weeks, especially where the (communicating)roads are poor and seasonal. This results in incon-sistent pumping and thus inconsistent water supplies.Further, the fuel allocated to pumping stations maynot be sufficient to run the electric generating sets forperiods long enough for water to reach every user.In most rural pumping stations, water is pumped onlyfor three hours daily and sometimes for four days ina week. Water supply to communities under such asituation cannot be adequate. Fuel shortage is an ad-ministrative problem and may be solved by having amore effective fuel distributing system. Instead of acentral distributing system, local governments shouldbe responsible for the fuel used in their areas of au-thority. The local communities may even fuel the en-gines directly. A more lasting solution would be toconnect all water pumping stations to the NationalElectricity grid (NEPA).

The small rural communities should not be ignoredin the design of state water supply schemes, as is cur-rently the practice. These communities constitute morethan 30% of the state populations and must be con-sidered in the water supply design especially now thatthe government is encouraging rural resettlement. Thegeneral water resources potentials of these areas havealready been established. What needs to be done isto establish the water resources of each specific com-munity and select an appropriate scheme for the com-

munity. Already it has been shown that schemes usingshallow wells with hand pump or hand-dug wells withsurface pump are suitable for such small rural com-munities in terms of economy and adequacy. Suchhand pumps must be sturdy, corrosion and weatherresistant and easy to operate and to maintain. Thehandpump — Indian Mark II — which has been de-veloped under UNICEF sponsorship meets most ofthese requirements. It also facilitates the lifting of wa-ter by hand from depths of up to 70m. The successof the UNICEF rural water scheme using this typeof technology should be a good case study. The mainproblem of the scheme is that the pump requires ser-vicing about once a year. The annual maintenance costper borehole is less than a hundred Naira and can befunded by the communities if effectively organised andsupervised. It is even likely that the general opera-tion of the borehole would be more satisfactory if thewells are owned by the communities as they will havea vested and vital interest in their proper functioning.

The success of the UNICEFrural water scheme using thistype of technology should bea good case study.

It should be remembered always that the existingtraditional water supply systems in the communitieswill compete with the newly devloped systems. Suchtraditional systems may not be sanitary or adequatebut once they have been traditionally accepted, it isusually difficult to ignore them. Sometimes more prej-udice against the earthy taste of ground water or a mal-functioning handpump can switch a whole commu-nity opinion against the new system. For the rural pop-ulation to accept the newly developed ground-watersupply, the following criteria must be satisfied [6]:

1. The population must be convinced through ed-ucation that the new supply is free from all dis-eases and is potable;

2. The new supply must be adequate both in quan-tity and quality;

3. It must be suitably located and distributed. Forexample, it should be closer to the communitythan the traditional source; and

4. The new supply must be dependable, hence atthe start, the borehole should be properly con-structed and the handpump sturdily built to with-stand any possible abuse. Both borehole andpump must be maintained regularly.

If these conditions are not satisfied, the population in-variably drifts back to the traditional source.

The decision by the Directorate on Rural Devel-opment to supply water to all rural .communities

44 Water International

through boreholes equipped with hand pumps is a wisedecision in the right direction. However as establishedin this paper the hand pumped borehole project is notviable in all the rural communities in Nigeria. Hydro-geologic and hydraulic conditions at the subsurfacemay render the project unworkable. A better approachmay be to accurately establish the nature of the waterresources for each community and select the mostappropriate scheme based on cost analysis of the alter-native schemes. The guidelines given in this paper mayform a basic framework for such a comprehensiveapproach.ACKNOWLEDGMENT

Drs. K. M. Onuoha and C. O. Okagbue both of theDepartment of Geology, University of Nigeria re-viewed the manuscript. Mr. Tawari of the Federal De-partment of Water Resources, Enugu supplied someuseful information, the Enplan Group of ConsultingEngineers, Enugu provided some financial assistance;Mrs. E. V. I. Okoyeocha typed the manuscript whileMr. F. Ozoani drafted the figures. These contribu-tions are gratefully acknowledged.

REFERENCES

; Wilson. R. C. and A.C.N'. Bair,, \92S. The Geology of eastern rail-way: section 1, Port Harcoun to Enugu. Geological Survey, Nig. Bul-letin. No. 8. 95p.

2 Anon, 1983. Groundwater Management — An Overview. Contribu-tion of the Water Resources Branch of the United Nations at the Pro-ceedings of the International Symposium on Groundwater in WaterResources Planning. IAHS Publication No. 142. vol. 2, pp. 277-289.

3 Egboka, B.C.E.. R. E. Mbanugoh, N.S. Nwogute, and K.O. Uma1986. Positive implications of hand-dug wells for water resources man-agement in a developing economy. Published in the proceedings ofthe groundwater resources seminar of the Nigerian water and sani-tation association (NIWASA), Lagos. Nigeria.

4 Enplan Group. 1977. Water supply to old Okigwe Division includingMbano, Eliti and Isiukwuato: Preliminary investigation report.

5 Balasha-Jalon consultants and engineers, 1980. Imo State Rural Wa-ter Scheme: First planning report.

6 Bannerman, R.R. 1975. The role of groundwater in rural water sup-plies in Ghana. Hydrological Sciences journal, vol. XX. pp. 191-201.

7 Uma. K.O., 1984a. Failure of Water supply scheme in Nigeria withparticular reference to Anambra and Imo Slates. Paper presented atthe symposium on Earth Sciences and the Engineering industry heldat Anambra State University of Technology, Awka Campus, 23rd June.1984.

8 Uma, K. O. 1984b. Water resources potentials of Owerri and its en-virons. Unpl. M.Sc. Thesis. University of Nigeria. Nsukka, Nigeria.

9 Uma, K.O.. and B.C.E. Egboka, 1986 Hydrogeochemistry. contam-inant transport and tectonic effects in Okposi-Uburu salt lake area.Hydrological Sciences Journal. Vol. 31.

CALENDAR OF FUTURE MEETINGSINVOLVING IWRAMar. 14-18. 1988

Mar. 19-24. 1988

May 9-13, 1988

May 29-June 3, 1988

June 5-9, 1988

June 27-July 1. 1988

Nov. 7-12, 1988

Nov. 10-12, 1988

Nov. 16-19, 1988

Dec. 15-17. 1988

June 5-10, 1989

June 19-23, 1989

International Conference on Computer Methods and Water Resources.Rabat, Morocco.

Tutorial on various topics offered following the International Confer-ence on Computer Methods and Water Resources. Rabat, Morocco.

Seventeenth Annual Short Course on "Hierarchical-MultiobjectiveApproach in Water Resources Planning and Management, 1988 Theme;Methodologies in Risk Assessment/Management and their Incorpo-ration in Decision Support Systems." Charlottesville. Virginia, USA.

Vlth World Congress on Water Resources — Water for WorldDevelopment. Ottawa, Ontario. Canada.

Short courses offered following the Vlth World Congress on WaterResources, University of Ottawa, Ottawa. Ontario, Canada.

International Workshop on Water Related Problems in Societal Plan-ning and Decision Making. Stockholm. Sweden.

Slate of the Art of Hydrology and Hydrogeology of Arid and Semi-arid Regions of Africa. Ouagadongou. Burkina Faso, Africa.

International Seminar on Hydrology of Extremes (Floods and LowFlows). Roorkee, India.

International Water Resources Conference on Water Resources Plan-ning and Management in a Developing Economy. Benin City, Nigeria.

International Seminar on Water Resources Education and Training.New Delhi, India.

40th International Commission on Irrigation and Drainage ExecutiveCouncil Meeting. Ottawa^ Canada.

International Symposium on Integrated Approaches to Water Pollu-tion Problems. Lisbon, Portugal.

CONTRIBUTORS DURING1987

Thanks are due to the following members whocontributed USS5 or more to the Associationduring 1987:NAME LOCATIONT. Dracos SwitzerlandJohn A. Kay United KingdomMarcel Andre Meyer SurinameUniversity of Petroleumand MineralsThomas C. WilliamsKirk R. WheelerJohn A. DracupSu-Won KirnTakeshi HataSoontak LeeOtto LangeneggerKon C. TaiMohammd Taghi MonzaviCharles R. JenkinsGlenn E. StoutTa-Wei David SoongRobert N. Cheetham, Jr.Harvey O. BanksHsin Hsiung ChenGilbert F. WhiteSuprabhat SenguptaClaude J. BuffetShow-Chyuan ChuChiranjib K. SarkarRoger T. KilgoreMaria Concepcion Donoso

Saudi ArabiaU.S.A.U.S.A.U.S.A.South KoreaJapanKoreaIvory CoastAustraliaU.S.A.U.S.A.U.S.A.U.S.A.U.S.A.U.S.A.TaiwanU.S.A.U.S.A.HaitiTaiwanU.S.A.U.S.A.Panama

Vol. 13, No. 1 (1988) 45