After a civil war lasting five years, the democratically elected Sierra Leone government signed a peace treaty with the rebel faction in November 1996 and the country intensified the reconstruction of its infrastructure.
This paper describes the aims, the existing situation, the various stages and the main conclusions of the World Bank financed Master Plan study for the water supply of the three provincial capitals (Bo, Kenema and Makeni). The study was undertaken by Howard Humphreys (HH) as lead consultant, in association with Dutch consultant IWACO, and local consultants ENGCON and Techsult

Claire Emberson (7224155)

English

Loughborough University Institutional Repository

X   MISCELLANEOUS: EMBERSON41123rd WEDC Conference Durban, South Africa, 1997Reconstruction in Sierra LeoneClaire Emberson, UKWATER AND SANITATION FOR ALL: PARTNERSHIPS AND INNOVATIONSAFTER A CIVIL war lasting five years, the democraticallyelected Sierra Leone government signed a peace treaty withthe rebel faction in November 1996 and the countryintensified the reconstruction of its infrastructure.This paper describes the aims, the existing situation, thevarious stages and the main conclusions of the World Bankfinanced Master Plan study for the water supply of thethree provincial capitals (Bo, Kenema and Makeni). Thestudy was undertaken by Howard Humphreys (HH) aslead consultant, in association with Dutch consultantIWACO, and local consultants ENGCON and Techsult.Aims of the studyIn October 1995, whilst the civil war was still severelyrestricting activities outside Freetown, the capital city,Brown and Root Consulting Arm, Howard Humphreys(HH) were commissioned by the Department of Energyand Power, on behalf of the Sierra Leone Water Company,to carry out a Master Plan study. Its aim is to provide aflexible staged development framework to the year 2020for the water supply to the three towns. From the MasterPlan, the first phase works will be determined to satisfy theneeds in 2005. A parallel study by management consult-ants, also financed by the World Bank, considers theinstitutional and financial aspects of the Sierra LeoneWater Company, with a particular emphasis on sustainability.Existing situationBo, Kenema and Makeni are situated inland between180km and 300km east of Freetown (Figure 1). All threetowns have a piped water supply infrastructure but expe-rience an acute water shortage for a number of reasons:• population explosion: due to the insecurity in thecountryside, large numbers of displaced persons movedinto the towns;• poor maintenance: the existing systems suffered fromyears of under-investment;• shortages in the power supply leading to lengthy inter-ruptions of the system.As a result, current per capita consumption for most ofthe population in the three towns has been estimated at abare minimum of 10 to 15 litres per day, out of which watersupplied from the distribution system forms only a smallproportion. None of the towns has a waterborne sanita-tion system.BoBo is the second largest town of Sierra Leone and thecapital of the Southern Province. In 1996, the populationwas estimated at 245,000 out of which 158,000 werepersons displaced by the hostilities. The only industry isbaby food manufacturing. Water supply is obtained mainlyfrom two sources: the public water system and privatewater wells. The first public water system was constructedin the 1950’s with an intake on the Sewa River 10km southof the town. Treatment works with flocculation, sedimen-tation, filtration and disinfection were built close to theintake, with an output of 2,700m3/d. In the early 1980’sthe original system was augmented by the construction ofa new intake, treatment works and transmission mains todeliver 8,600m3/d into supply. The original treatmentworks were abandoned and are now beyond rehabilita-tion. The current system suffers from lack of maintenanceand cannot deliver the design output. The main problem inBo is linked to failures of the electrical and mechanicalequipment. When both duty and standby intake pumpsbroke down in 1996, no water was distributed in the townfor several weeks. Consequently, the population becamemore and more reliant on shallow wells. The capacity ofthe wells decreases in the dry season, many dry outcompletely at the end of the dry season.KenemaKenema is the provincial capital of the Eastern Province. In1996, the estimated population was 196,000 of which114,000 were persons displaced by the hostilities. Kenemais the centre of the diamond trade and agricultural produc-Figure 1. Map of Sierra LeoneX   MISCELLANEOUS: EMBERSON412tion of coffee, cocoa, palm oil and other cash crops. Sinceforest industries ceased to operate, there are no industrialactivities in Kenema. The first public water supply systemwas installed in the 1950’s based on gravity supply fromtwo intakes in the nearby Kambui Hills. In the early 1980’sthe supply was augmented by a pumped supply from theMoa River, 8km south of the town. The treatment planthad a capacity of 11,000 m3/d. The works were opera-tional for only six months due to electrical problems andlack of spare parts. The works were abandoned, becamederelict and served as an army base during the war. Theintake, clarifiers, filters, buildings and some of the pumpsand pipework are still in place but in extremely poor stateof repair.Currently, the gravity system provides the only pipeborne water supply. It can satisfy less than 10 per cent ofthe needs of the existing population who now relies mainlyon shallow dug wells. On the gravity system, lack of spareparts has led to emergency repairs using inappropriatematerials, for instance, it is not uncommon to see leakingjoints held together by plastic bags. The water receives notreatment before entering the system.MakeniMakeni is the provincial capital of the Northern Region. In1996, the population was estimated at 104,000 out ofwhich 39,000 were displaced. There are few commercialand industrial activities in Makeni, the main industry beingtobacco. The first public supply was constructed in the1950’s for a population of 15,000. An intake was con-structed on the Mabole River 9km away from the town.Water was pumped to a small impoundment (8000 m3) onthe Wusum Hill from where water could gravitate to thetreatment works further down the hillside. The impound-ment also acted as sedimentation tank upstream of thetreatment works. During the rainy season, the impound-ment captures the waters from the Wusum stream, whichsignificantly reduces the need for pumping. It is grosslyinsufficient during the dry season. In the 1980’s the origi-nal intake and treatment works were augmented by a newsystem capable of delivering 9,600 m3/d. However, short-ages of fuel mean that in the dry season, the intake worksare operated for only a few hours every two or three days.Supply to the town is insufficient and the population nowrelies mainly on shallow wells which tend to dry up in thedry season.Stages of the studyHH as lead consultant with overall responsibility for thestudy provided the team leader and water treatment,hydraulic, water supply and mechanical/electrical special-ists. IWACO provided the water resources, socio-eco-nomic (including water demand) and environmental spe-cialists. Local knowledge, which is essential for such astudy, came from its local consultants who providedcounterpart socio-economist, hydrologist, environmental-ist and mechanical/electrical engineer as well as surveyorsand technicians and logistical support.Due to the prevailing security situation, the plannedstudy approach and programme were completely revisedin consultation with the client. The socio-economists vis-ited two out of the three towns in January 1996 to carry outa survey on water use and willingness and ability to pay.The water resources specialist carried out a comprehen-sive desk study based on documentation collected inFreetown and world-wide. In May 96, a second attemptwas made to visit all three towns. This was successful.Unfortunately, access was still not possible outside thetowns. This became possible only after signature of thepeace treaty. A third visit took place in February andMarch 1997.Close cooperation with the client was involved at allstages, both at headquarters and in the towns. Town mapshave not been updated for many years and there are nophysical development plans, nor are any being prepared.Development is therefore uncontrolled. One of the firstexercises therefore was to produce town maps, albeitcrude ones, to indicate the current extent of developmentand identify those areas which could accommodate futureexpansion of the towns.The following documents have been prepared: an Incep-tion Report after the January 96 visit, a draft WaterResources Desk Study in July 96, a Draft Water SupplyMaster Plan in November 96. Draft bid documents forPhoto 1. Kenema – filter bedsX   MISCELLANEOUS: EMBERSON413drilling to investigate underground water resources anddraft bid documents for the first stage works are inpreparation.Water resourcesBo is situated on a watershed. The nearest hills are 10kmaway and with small catchments. Possibilities for gravityfed supply are limited. Various projects started before thewar indicated the presence of groundwater near Bo, how-ever the yields were low. The study led to the conclusionthat the main reliable water source for Bo is the SewaRiver. The Sewa is exploited for gold using traditionalpanning methods as well as large scale sand excavation bydredging. As a consequence, the river can become heavilysilt laden.In Kenema, a number of spring based sources have beenidentified in the past. However, this potential supply islimited, especially in the dry season. It is also fragile due tothe increasing deforestation of the Kambui Hills. Kenemais situated in a hard rock region. Most aquifer systems arediscontinuous with groundwater occurring in the weath-ered and locally fractured zones of hard rock. The poten-tial for groundwater based supply sufficient for the townis remote. The only reliable supply for Kenema is the MoaRiver. However with upstream mining activities, the riverwater contains a high concentration of suspended solids.Makeni is surrounded by bare rocky hills with high run-off during the rainy season but no run-off during the dryseason. Little is known of the groundwater resources butthe geology does not appear favourable for sufficientsupply to the town. The only reliable source of watersupply is the Mabole River.Required water productionEstimating the future demand requires estimates of thepopulation at the various horizons. In all three townsnormal population growth was disrupted by an influx ofdisplaced persons. The number of those displaced whointended to remain in the towns after the end of hostilitieswas estimated from comprehensive surveys by the socio-economists and from discussions with the relevant minis-tries, with United Nations representatives and with vari-ous non-governmental organisations. A sensitivity analy-sis was carried out to understand the impact of variouspercentages of people returning to their villages on theestimated population in 2005. Currently, it is anticipatedthat approximately 30 per cent of the displaced populationwill not return to their villages. The design of the first stageworks is based on this assumption.There are no domestic meters in any of the towns, andnone of the meters at the treatment works or from thestorage reservoirs work. As a result there are no historicdata on which to base demands. For the purpose of theMaster Plan, water demand had been based on the follow-ing assumed domestic consumption figures:Standpipe 20 l.c.dSingle yard tap 45 l.c.dHouse connection 120 l.c.dAn allowance of 10 per cent of the domestic require-ments has been taken for non-domestic consumption.The existing systems have not been fully pressurised foryears. Some sections have not received water for decades.It is anticipated that the first commissioning of the systemswill show areas with leakages higher than anticipated. Forthe purposes of the Master Plan, un-accounted for waterhas been taken at 30 per cent in 2005, falling to 25 per centin 2020.The estimate of water requirements is as follows:2005 2020Bo 10,700 m3/d 22,700 m3/dKenema 8,600 m3/d 17,000 m3/dMakeni 7,200 m3/d 12,500 m3/dConclusionsGeneralThe main conclusion of the study was that all three townsare already provided with a basic infrastructure compris-ing intakes, treatment works, transmission mains, reser-voirs and distribution mains. In each case, the currentsource of water is the most reliable source and the infra-structure is almost sufficient to satisfy the needs of thepopulation at 2005.First stage works (2005)The first stage works aim at rehabilitating this infrastruc-ture and as much as possible simplifying the process. Forinstance, in two of the three towns, the existing servicereservoirs float on the distribution system and receivewater only when direct demand on the system allows. Thisarrangement will be modified so that the transmissionsystems feed only the reservoirs and the distribution sys-tems will be fed by gravity from the reservoirs. In all thetowns, new reservoirs are required to bring storage up to12 hours.Use of slow sand filtration has been investigated as analternative treatment, however the quality of the raw wateris poor with high suspended solids (mining activitiesupstream), thus requiring construction of pre-settlementfacilities.It will be important that suitable training be provided tostaff at all levels of the Sierra Leone Water Company. Thisaspect is being investigated by the management consult-ants.Environmental impactsIn all three towns, one negative impact of the works will beon sanitation. Currently the population relies on pit la-trines, septic tanks and on the storm drainage system todispose of waste water. It has been often observed that withincreased reliability of the water supply, flush toilets areX   MISCELLANEOUS: EMBERSON414installed in houses and the existing systems are no longerable to cope with increased water quantity. Mitigationmeasures will be required in the long run. In the immediate,it is recommended that cleaning of the existing stormdrains should be carried out regularly: currently, many areblocked by material washed off the unsurfaced roads.In Kenema, the impact of diverting streams into thedistribution system was examined in detail. To the east ofKenema, one village relies completely on water from oneof the streams to be diverted. It is proposed that compen-sation will be provided by an extension of the distributionnetwork. Of main concern was the possible negativeimpact on bio-diversity downstream of the hill catchments.After a detailed site visit it was concluded that the problemwould not be acute as anticipated as the impoundedcatchment forms only a small proportion of the overallcatchment of the streams.In Kenema, deforestation on a large scale happened onthe Kambui hills during the war, for firewood, agricultureand security reasons. At the current rate the hill-damscatchments could be affected within a few years, thusendangering the gravity supply to the town. The ForestryCommission is well aware of this problem and has em-barked on a reforestation programme.In Makeni, the treatment works are situated at the edgeof the town. Until now, it appears that the sludge from thetreatment works has been disposed of in a stream crossingthe town. The stream is used for washing and bathing.New disposal areas will be selected.Immediate worksAlthough outside the scope of the study, an investigationwas carried out of immediate works which would allowregular water supply, even if insufficient, until implemen-tation of the first stage works. A shopping list was pre-pared which included items such as a new intake pump anda diesel generator for Bo, new ductile iron pipes, and alarge number of fittings such as joints. Toolkits andportable water testing kits were included, as well as basictools such as shovels and screwdrivers. It was proposedthat technical assistance be offered at the time of installingthe newly purchased equipment. The technical assistancewould be one person spending one month in each town tocarry out an overhaul of electrical and mechanical equip-ment as well as on the job training. A source of finance forthe immediate works is still being actively pursued. How-ever due to the problems currently faced by Sierra Leone,it is unclear when implementation will start.CLAIRE EMBERSON, Project Manager, Brown and Root/Howard Humphreys.

Reconstruction in Sierra Leone

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Reconstruction in Sierra Leone

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