The Sri Lankan government has committed itself to
introducing a participatory integrated approach to water
resource management to meet a growing water resource
problem in the country. Here the Menik Ganga catchment
in south east Sri Lanka is used as an example of the
problems that need to be addressed by the new policy

Ranjith B. Fernando (7221299)

Ruwan S. Liyanage (7221296)

English

Loughborough University Institutional Repository

LIYANAGE and FERNANDO13428th WEDC Conference Kolkata (Calcutta), India, 2002Demand responsive water supply in Sri LankaR. Liyanage and R. Fernando, Sri LankaSUSTAINABLE ENVIRONMENTAL SANITATION AND WATER SERVICESTHE SRI LANKAN government has committed itself tointroducing a participatory integrated approach to waterresource management to meet a growing water resourceproblem in the country. Here the Menik Ganga catchmentin south east Sri Lanka is used as an example of theproblems that need to be addressed by the new policy.The Sri Lanka problemThe average annual rainfall in Sri Lanka exceeds 1500mmper year and hardly anywhere does it fall below 1000mm;in highland areas it is over 5000mm. To suggest, therefore,that Sri Lanka has a water-resource problem might seemdifficult to believe; however problems do exist. Rainfall isstrongly seasonal and in the drier north western and southeastern parts of the island there are water shortages duringthe months of June, July and August when low rainfall iscombined with high evaporation rates. Groundwater re-sources that are of poor quality and limited extent com-pound surface water shortages in these regions.It would be too extreme to claim that Sri Lanka issuffering a water resource crisis, but serious seasonal watershortages combined with an ever-increasing demand in thewake of rapid economic development provide a warningsign of increasingly severe problems to come.In recognition of this fact the Sri Lankan government inApril 2000 set out the future policy for water resourcemanagement in the country in a document entitled ‘ TheNational Water Resources Policy and Institutional Ar-rangements’. The overall objective of the policy is to ensurethat future water resource management ensures ‘the use ofwater resources in an effective, efficient and equitablemanner, consistent with the social, economic and environ-mental needs of present and future generations’. A particu-lar stress was placed on the need for integrated waterresource management at the river basin scale with activeparticipation of local communities in the decision-makingprocesses.An excellent example of why this type of approach isrequired is provided by the problems currently being facedin the Menik Ganga(River) catchment in south east SriLanka.The catchmentThe Menik Ganga(River) rises in uplands 1600 metreshigh, from where it flows approximately 80 kilometres tothe coast; the total catchment area is 1272 square kilome-tres (refer table 02). Average annual rainfall varies enor-mously from over 2500 millimetres in the headwaters toless than 1000 millimetres at the coast. In the headwaterstea plantations dominate land use, but in the central sectioncultivation is given over chiefly to paddy and sugar cane; incontrast the lower third of the catchment forms part of theYala National Park.Groundwater occurs in basement complex gneisses, whichform aquifers of low yield, producing water of generallypoor quality.Demand and conflictThe estimated volume of water discharged annually by theMenik Ganga at the coast is 298 million cubic metres (refertable 02). But this impressive discharge is not evenlydistributed throughout the year. During the months ofJune, July and August the flow is dramatically reduced andin recent years has ceased completely for several weeks ata time in this dry period. But this is precisely the time whenthe water demand of the 271,000 population is at itshighest.The demands stem from a number of sources, but prin-cipally from the paddy farmers and sugar cane producerswho are based in the area. Sugar cane producers need waterto irrigate the nursery crop and for factory processing,while the paddy farmers require the water to produce theirsecond (Yala) crop. At the same time settlements such asButtala and Katteragama use the river to provide a domes-tic water supply (Figure 1). In the case of Kateragama,located in the lower part of the catchment, the problem ismade worse because as a sacred site it attracts over 100,000pilgrims during the holy season, which incongruouslyoccurs during the dry months of July and August. The YalaNational Park, situated in the lower third of the catchment,also requires a dry season supply of water to sustain itswildlife, including a large elephant population, during thedry season.Currently large-scale abstractions from the river eithervia diversion channels (anicuts) to the paddy fields, or bypumps to the sugar cane nurseries and town water supplysystems is not coordinated or controlled on a catchmentwide basis. The inevitable result has been conflict betweenthe major users and those minor users who also depend onthe river during these dry months (refer table 03). Underthese conditions it is not surprising that it is the down-stream users, notably the Kateragama domestic supply andthe Yala National Park, that have suffered most.LIYANAGE and FERNANDO135Water QualityIn addition to the problem of water quantity there are alsoa number of water quality issues to be resolved. Chiefamong these is the threat to the quality of the river wateritself. Tea cultivation which takes place mainly in theheadwaters poses a double threat; firstly in the form ofpesticides used on the crop being washed into the river andsecondly by tea estate workers settling along water chan-nels but having no access to proper sanitation. Faecalpollution has resulted from this practice.Further downstream the sugar factory and distillery havebeen accused of either deliberately or inadvertently dis-charging polluted water into the main channel causingproblems for paddy farmers and domestic water suppliersfurther downstream.To compound the situation much of the groundwaterpresent in the catchment also suffers from severe qualityproblems. Excessive hardness and high iron content iswidespread, while locally fluoride levels are well in excessof permitted WHO limits. Shallow supplies tend to be ofbetter quality, but crucially most dug wells tend to fail in thedry season and the population need to turn to the deepertube wells, which unfortunately produce water of poorerquality.The way forwardClearly, water resources in the Menik Ganga catchment arenot being managed in the effective, equitable, efficient andsustainable manner that is required by the recent nationalwater resource policy. The problem is to convert what is achaotic and ad hoc method of allocation and distributioninto a fully integrated water management system. Tosuccessfully achieve this long-term goal will require theadoption of some basic guiding principles.? The first and probably the most important is the needto involve local communities into the managementprocess. This participatory approach has been usedwith great success in India where for over 30 yearswatershed development programmes have transformedpreviously poorly - managed catchments into sustain-able, productive regions. Many of these schemes weredescribed in the October 2000 edition of Waterlines.  Asimilar participatory approach will be required to suc-cessfully implement any integrated water managementpolicy in the Menik Ganga. Involvement and participa-tion of local communities provides the best way for-ward to overcome the conflicts that will inevitably arisein any management system.? Water management in Sri Lanka is presently based onadministrative districts and divisions. An effective man-agement strategy, however, really needs to be based onthe hydrological unit, the catchment. To achieve thisaim will require some fundamental institutional re-structuring.? The water resource in the catchment needs to be accu-rately quantified; without knowing how much water isavailable makes effective water resource managementimpossible. A comprehensive hydrological monitoringnetwork including meterological stations, groundwatermonitoring points and flow gauging stations is there-fore essential.? A good decision making support system is required.Integrated management means that the impact of a widerange of factors needs to be taken into account. Thisincludes not only hydrological factors but social, eco-nomic and cultural effects. The links between thesefactors need to be specified and the way in which theyimpact on each other should be simulatedThis type of approach is a long-term venture, but the SriLankan government has recognised that to ensure thesustainability of future dry season water resources partici-patory integrated management at the basin scale offers thebest way forward.Recommendation & Conclusion(1) A catchment management committee Should be estab-lished comprising of relevant water authorities (Irriga-tion, drinking water, Administrative offices, NGOs,farmer organizations, Industries and Agriculture de-partment etc. The committee should review monthlywater issues, demand issues, quality issues and to takeremedial action accordingly.(2) Most settlers in highland areas located along waterpaths and they do not have proper sanitation facilities.Action should be taken to resettle them in away fromthe water paths and provide proper sanitation facilities.(3) Paddy is the popular traditional crop type in the dryzone in Sri Lanka which consume more water than theother crop types such as vegetable, fruits, grains etc.Onthe other hand ,most of the farmers have attitude onflood irrigation in their paddy field to obtain bumperharvest but in the reality as not do so. Introducing watersaving techniques, changing attitudes & anchorage onother multi seasonal crops would give advantages onintegrated water management during the dry period.RUWAN LIYANAGE, District Manager/Chief Engineer,Asian Development Bank Finded 3rd Community WaterSupplyand Sanitation Project, Sri LankaB RANJITH FERNANDO, Engineer, National WaterSupply and Drainage Board, Sri Lanka.LIYANAGE and FERNANDO136Year 2025 Demand (MCM) Water Allocation (MCM) Monaragala District Urban Centers Village Centers River Basin Demand Centers (No of GN Division) Demand at Urban Centers Demand at Village Centers Total Other District Overall Total (MCM) Surface water 90% Ground Water 10% Surface 40% Ground Water 35% Rain Water 25% Menik Ganga 21 6.06 5.35 11.41 4.25 15.66 7.48 0.82 2.94 2.57 1.84       Annual water Usage (MCM) Drinking Water Name of River Basin Catchment Area sq.Km Average Annual Rainfall (mm) Run off factor Run off (MCM) Irrigation Urban Centers Village Centers Industrial Other Base Flow Reservoirs Total Net Water Balance (MCM) Menik ganga 1272 1429 0.164 298 70 7.48 2.94 1.8 4.6 1.08 87.9 210.1  • Assumed that the present Irrigation demand will increase by 20% at year 2025 design horizon.       Water Requirement (Major) (MCM) Drinking Month Monthly Rainfall (mm) Runoff Coefficient 0.164 Runoff (MCM) Urban Centers Village  Centers Irrigation Industrial Others Base Flow Allocation Total (MCM) Surplus/Deficit (MCM) June 23 0.164 4.80 0.62 0.25 8.75 0.15 0.44 0.09 10.3 -5.50 July 21 0.164 4.38 0.62 0.25 8.75 0.15 0.44 0.09 10.3 -5.92 August 21 0.164 4.38 0.62 0.25 8.75 0.15 0.44 0.09 10.3 -5.92  Table 1. Menik ganga river basin - drinking water demand forecast (year 2025)Table 2. Assessment of surface run off and annual water budget along the Menik ganga river basin (year 2025 design horizon)Table 3. Dry flow water balance (year 2025 design horizons)Menik ganga river basin (catchment area 1272 sq.km)

Demand responsive water supply in Sri Lanka

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Demand responsive water supply in Sri Lanka

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