CHAPTER 1 CHAPTER 2 CHAPTER 3 Figure 1. Case Study Areas Figure 1. Case Study

Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in The Study of the Management of of Management the of Study The Resources Groundwater in 1. Background to the Study Area to the Study 1. Background

5

- 3 1.2 Study Area 1.2 Study The two main study areas selected for this analysis are the urban and suburban suburban areasareas of of (figure Colombo 1). andGroundwater use the in urbanagriculture is and discussed through the agro-wells (wells that are used for agricultural purposes) in the northwestern regions, while the impact from the tsunami is discussed through the 1). coastal groundwater resources (figure groundwater reserve. 1.1 Introduction This investigation, “The Study of Management of Groundwater Resources Management Policy Water Project, in a collaboration between Srithe Institute for Global Lanka,”Environmental Strategies (IGES) in is part of the Sustainable Hayama, Japan and the Department of Civil Engineering of the University of , in Peradeniya, Sri The Lanka. study mainly focuses on groundwater and its alternative water source management in two urban centers in Sri Lanka. In addition, the study briefly discusses groundwater use in agriculture and the impacts of the tsunami on the coastal

110 CHAPTER

CHAPTER 3 3 CHAPTER CHAPTER CHAPTER 2 2 CHAPTER CHAPTER CHAPTER 1 1 CHAPTER CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 111 Divisions,” the village 1 to 1990 Kandy) is limited to only five 1961-1990 Grama Niladari Colombo) includes twenty divisional secretariat divisions covering the a portion of the Kandy district. a portion of the Kandy Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Ratnayake and Hearth, 2005 1911-1961 Source: Source: Figure 2. Rainfall Changes in Sri Lanka during the Period from 191 Colombo is located in the coastal plains of the western region of the country. The terrain in Colombo consists consists Colombo in terrain The country. the of region western the of plains coastal the in located is Colombo : : Kandy is a plateau in the central mountainous region and lies 500 to 700 m above sea level. The terrain in the

whole districts of Colombo and Gampaha, while the Kandy study area (hereafter called this plateau consists of undulating plains with hillocks formed by the drainage paths. this plateau consists of undulating plains Kandy of gently undulating plains with a high density of drainage paths. of gently undulating plains with a high Colombo 1.3 Topography and Climate 1.3 Topography Topography (1) Sri Lanka has a central mountainous region rising up to about 2,500 m above mean sea level, with the highest elevations covered by virgin forests and grasslands. The surrounding plains, which rise to about 50 to 100 m above sea level, are the population distribution is lower. scrubland where homesteads, but still have virgin used for agriculture and largely divisional secretariat divisions covering divisional secretariat (1) Administrative Structure Administrative (1) Sri Lanka has nine provinces, each with its own local government. These provinces are further subdivided into a total of twenty four districts. These are again subdivided into divisional secretariat areas responsible for civil affairs, which in turn are further divided into the smallest administrative divisions, called “ Kandy City area does not contain many steep, plunging slopes except in the surrounding mountains. The topography in level. The Colombo study area (hereafter called

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 ss ei ss % Gn ei 49 ss Gn otite otite ei Bi itite itite Gn Bo otite otite Bi et et rs blende blende rn rn he Ho Ga Ot ss rs

% ss ei he ei ss 14 Gn Ot ss % Gn nei c ei blende G 14 rn Gn c c itite itite ss ti ti e e nokiti e e Ho Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in it it Bo ss ar nei ani % ot ot noki G ss nei Bi Ch Gr Bi 10 ar

7% ei G 6% et Ch Gn rn anitic Gr Ga Figure 3. Geological Classification of Bed-Rock Types in Kandy Study Area in Kandy Study of Bed-Rock Types Figure 3. Geological Classification Regionally, Colombo and its suburbs accommodate the densest population in Sri Lanka. As of 2001 (last : : The geology of Colombo is representative of the geology of the western coast of Sri Lanka and has existed The main geological feature of Kandy City and its surrounding area is a band of marble one kilometer thick.

: official count - Sri Lanka 1.7% of rate Datagrowth population Sheetannual average an 2004with million, 4.3 andat placed was Sriarea study Colombo Lankain living population Department of Census and Statistics web page), the total This band is classified as coarse crystalline mainly made up of calcite. Calcsilicate gneiss intruded as bands within the host marble including scapolite and spinel as additional minerals. Collectively these two brown rock overburden latosolic typessoil that on give average ranges risein thickness from to one to red-three meters. The major bedrock types available within the Kandy study area are summarized as percentages in figure 3 The below. main rock type identified is Biotite Gneiss, which cover almost half the area. Hornblende biotite gneiss, charnockitic gneiss, garnet biotite gneiss 1.5 Socio Economic Conditions Colombo and granitic gneiss are also present in considerable percentages. and granitic gneiss are also present in considerable Kandy to the productive overburden along tributary banks. to the productive overburden along tributary Colombo 1.4 Geology for much of the Quaternary era. Bore holes drilled in central Colombo City show that this area once formed an estuary of the and the River, the two main rivers that drain into the sea on the western coast. A few kilometers upstream in the inland valleys, there is a high-level gravel formation consisting of quartz pebbles embedded in a matrix of laterite separated with pebble-free layers of laterite. The floodplains along alluvial The deposits. floodplains of theKelani River also provide thick alluvial profiles for unconfined aquifers, riversin addition consist mainly of corresponding to the lengths of wet spells and increasing exploitation with increased use during dry spells. with increased use during dry lengths of wet spells and increasing exploitation corresponding to the (2) Climate In terms of the amount and pattern of rainfall received, Sri Lanka can beThese zones are divided referred to into as the threewet zone (usually different over 2,000 climatic mm annual zones. rainfall), the intermediate zone and the dry zone (below 1,500 mm rainfall). In general, rainfall in the island monsoons and during mainlythe inter-monsoons. Both selected occurs study areas are located duringin the wet zone, thewhich receive average southwest and northeast annual rainfall of about 1,900 mm. With the recent climaticlines changesfrom 1911 happening,to 1940however, comparedthe withaverage the rainfallaverage iso- rainfall significantlyiso-lines fromdecreased 1961 all to over1990 theshow countrythat the (figure rainfall 2) Furtherhas and itespecially is revealedaround thatKandy the (Ratnayakelengths andof theHerath dry 2005).periods periods havehave decreased.increased These all changes over in the rainfall country have and directly the affected lengthsgroundwater of by wet reducing the recharge time

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 113 - % 8.3 -4.3 48.2 -14.6 110.4 change ) 2 - 8.3 46.5 10.4 1996 (km 104.4 149.9 ) 2 - 5.6 9.6 as groundwater, and a further 22.1 1988 (km 109.1 175.6 3 km . Land use changes during the recent past 2 Table 2. Land-Use Changes in Kandy Table Land-Use Type as surface water, 8 Agricultural land Built-up land Forests Domestic gardens Water bodies Water marshes and Mangroves 3 Source: Land use maps, Survey Department of Sri Lanka Source: km . Compared to Colombo, major land use changes observed 2 % 39.6 -16.2 -33.9 -59.4 -38.8 933.1 change ) 2 30.5 21.5 32.4 1998 (km 799.1 131.2 560.9 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in 2. State of Water Resources 2. State of Water ) 2 53 12.7 36.4 52.9 1987 (km 572.5 848.1 The : total land extent of the Colombo case study area is 1,575.6 km Table 1. Land-Use Changes in Colombo Table The population within the Kandy study area in 2001 was 0.81 million (Sri Lanka Data Sheet 2004 and Sri Land-Use Type : : The selected study area in Kandy is only 322 km as overlapping The water. wet zone, which receives over 1,900 mm rainfall annually on average, generates 49% 3 Domestic gardens Agricultural land Built-up land Forests Water bodies Water marshes and Mangroves Source: Land use maps, Survey Department of Sri Lanka Source: km

in Colombo are tabulated in table 1 According below. to the data, the main land use change observed in the Colombo study area is the rapid increase in built-up land, which grew by 933% over the eleven years built-upfrom 1987 area to replaced1998. This domestic gardens, water bodies and marshes consists(a typicalof mixed domesticvegetation garden that in surroundsSri theLanka house).mainly There is also a significant decline in the extent of domestic in Kandy were in forest cover, built-up area and domestic gardens. Forest cover increased over 100% during the eight areas built-up in change The land. and agricultural gardens domestic the replaces increase This to 1996. 1988 from years of the total runoff for the Because entire of country. this runoff, the overburden in wet zone is kept moist, which allows Lanka Department of Census and Statistics web page). Thoughcomparison to Colombo its population is very small. The average Kandy population growth rate during the past 20 years isin the the second-largest city in the country, Kandy in region is estimated as 1.0%. This value is lower than the country average of As 1.2%. of 2002, the contribution page). 9.4% (Central Bank of Sri Lanka web from the Kandy district was only to the national GDP 7 According to the “Earth Trends” country profile on Sri Lanka (2003), the total renewable water resources available in the freshwater ecosystems of Sri Lanka are estimated at 49 groundwater resources in the area. However, in both these study areas, a significant reductionpaddies, which cover nearly 20% of the wastotal land area. This change is observednot clearly reflected in the land use withmaps. Paddy respect to the cropping intensitycultivation in of the last decade has dropped compared to the late 1970s, and of this irrigation may water in substantiallythe paddy restrictfields, thereby the reducing the amount sub-surface flow and recharge, which in turn influence the Kandy was only 48.2%. gardens observed, mainly due to migration to commercial crops. gardens observed, mainly due to migration Colombo 1.6 Land Use Kandy during the past 20 According years. to the Central Bank of Sri Lanka, the per country’s capita was GDP at 473 USD in 1990, and had increased to 1,160 USD by 2005. Of this national the GDP, western province of which Colombo is the capital contributes almost one half (estimated at 48.1% in year Therefore 2002). Colombo, where most of the industrial, commercial and administrative activities taking place, plays a very important role with respect to the overalleconomy. national

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 : The basin hydrology indicates that there is a fair amount of Groundwater in Kandy exists mostly in the form of semi- : a. Groundwater Hydrogeology of study locations Hydrogeology a. Groundwater confined aquifers in the first 100 m of the bedrock. This groundwater exits both as small pockets of underground reservoirs and as groundwater.fissure The yields of these aquifers are notand are verylimited as wellthey recharge knownvery slowly. In addition, there exists high-yielding groundwater resources along the alluvial flood plains of by the river water. that are mostly recharged Colombo groundwater potential both in the alluvial aquifers and bedrock. The prominent aquifer bedrock types in the basin are quartzite and a few crystalline limestone (marble) bands. The secondary porosity of these formations provides good conditions for deep aquifers. The sand/gravel alluvialaquifers in the basin are recharged by rainfall and seepage from the rivers. High-potential porous residual laterites also contribute to groundwater supplies. During droughts, basin. most alluvial aquifers in the recharge river water and springs Kandy Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in

Kelani River, with the third largest watershed in the country, is the main surface water source for the Types in Sri Lanka Types : Figure 4. Distribution of the Major Aquifer Distribution of the Major Figure 4. 2005 Panabokke and Perera Modified from Source: Colombo region. Therefore, the Kelani River water is playing an importanteconomy, sincerole it with drainsrespect the to mostthe fertileIsland’s overalllands in the wet important zone administrative district and of interceptsColombo the capital the of mostSri Lanka. populatedIn the Colombo and study economicallyarea, the principal use of water from the Kelani River is for water including supply, to the Greater Colombo area Ambatale. at The Kelani River Colombo Surface water resources (2) Surface water Since both study areas are located in the wet zone, they are blessed with plenty of rainfall and therefore surface water. However, when the total surface water availability of the areas is centresconsidered, and dependingthe on locationthe oflocation waterof resourcesdemand with respect resources to for some thedemand centres demandin the study centres,regions. Also, even though itthe available iswater resource is difficultgood, when to find suitableone considers water the total aggregate water availability, the variations over space and time from the historical perspective demand a proper management strategy. weathered zones of the underlying metamorphic bedrock. weathered zones of the underlying metamorphic Groundwater Resource (1) Groundwater areas are rich in surface water resources. areas are rich in surface Resource 2.1 Water In terms of river basins, the major part of the Colombo study area is located in the lower catchment of the Kelani River, while the entire Kandy study area is located in the middle catchment of the Mahaweli River basin. Therefore both these considerable considerable subsurface flow through macro pores. These subsurface flows are tapped using shallow wells throughout of the population. for the majority areas, providing water the study There are six main type of groundwater aquifers demarcatedaquifers, coastal sand aquifers, deep andconfined aquifers, lateritic (cabook) aquifers, identifiedalluvial aquifers and shallow regolith in Sri Lanka. They are shallow karsticaquifers in the hard rock region. Figure 4 shows the distribution of these aquifers within the Perera 2005). country In addition to (Panabokke these main aquifers, and a large number of small groundwater pockets can be found throughout the country. These aquifers occur either in isolated patches of soil cover over the bedrock or in the fracture and

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 115 , nearly 16% 2 originating at 2 of which nearly 65% discharges into the 3 m . A summary A . of the groundwater use within the 3 In addition to rainfall runoff, the only other major : surface water source available within the Kandy study thearea Mahaweliis River. The Mahaweli River is the inlongest Sri riverLanka; originating in the highlands northeasterlyand running directionin the through Kandy to to the Colombo study area. Kandy is 144 km long and drains an area of 2,292 km levels above 1,500 m on the steep ofslopes the central of highlands. theIn theirwestern descent the rim main river and its numerous tributaries travel through deep, structurally controlled lower and higher at directions many in oriented generally valleys, elevations. The main river eventually empties intoOcean on thethe west Indiancoast of Sri Lanka just few kilometers north of Colombo. The Kelani catchment receives an average annual precipitation of 3,718 mm generating a surface runoff volume of about 8,600 million Indian Ocean. In addition to the Kelani River, Attanagalu Oya, a non-perennial stream, also flows through the studyhas arealimited butsignificance with respect to supplying water to the of the total land area of the island. As this perennial river flows through the study area, a considerable amount of surface water is available in the study area throughout the year. Furthermore, the tributaries , Pinga Oya, and the Nanu Oya of the ocean and draining an area of around 10,300 km Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in

River Basins in Sri Lanka and within River Basins in Sri Lanka and within Areas Study

Source: Sri Lanka National Water Development Report 2006 Sri Lanka National Water Source: Figure 5.

Mahaweli River have the potential to supply substantial amounts of water during the rainy seasons to the Kandy study as area. the However, major portion of the Mahaweli River flow through Kandy is regulated at Polgolla and diverted for hydropower and for agriculture towards large irrigation networks in dry zones of Sri Lanka, satisfying these demands two study areas is tabulated in table 3. With With respect to piped water supply, presently there are 93 urban and rural water groundwater annual of amount total The supply supply. total the of 31% for schemesaccounting groundwater, on purely rely that country operating across the abstraction from these 93 schemes is estimated to exceed 16 million m The demand for water in Sri Lanka is steadily increasing, particularly for urban/rural water supplies, irrigated agriculture agriculture irrigated supplies, water urban/rural for particularly increasing, steadily is Lanka Sri in water for demand The groundwater pressure on the available considerable This rapid increase in demand is exerting sector. and in the industrial Sanitation-2000,” and Supply Water for Program Monitoring “Joint on report WHO/UNICEF the to According resources. only 76.1% of the urban population was supplied with a piped supply compared in to rural 11.4% areas, while the urban and rural populations using underground well-water were estimated at 22.4% and 71.8% respectively (that rural populations urban in 1999 and were 5.86 and 13.05 millions Also, respectively). in recent times use of groundwater is on an increasing trend because of high piped water tariffs and restricted hours for These water two supply. issues have forced the industrial and commercial users and some individual domestic users around the country who are alreadywith piped supplied water to have a supplementary groundwater supply to reduce costs and to ensure a margin of safety in their and on deep wells because groundwater is free, safe, of good quality, Of these, most industries today rely heavily supply. able to be autonomously managed. Presently, there are around 30,000 deep groundwater wells throughout the country registered with the Water Resources Board (WRB). However, this figure does not wellstake into inaccount Sriall groundwaterLanka because wells and overseas projects have not been included in this registration. (NWS&DB), private drilling organizations constructed/developed by the National Water Supply and the Drainage Board (1) Groundwater together with the Kandy water requirements in the future is of some concern. together with the Kandy water requirements Practices Usage 2.2 Water

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 52.0* 8,567 1,754* Kandy 41,000 . Except for a small 3 m annually. 3 m 890 75.4 5,859 156,000 Gampaha districts Colombo 0 342 34.8 78,000 Colombo district Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Table 3. Groundwater Use in the Study Areas the Study Use in 3. Groundwater Table /s flow is necessary at Ambatale to prevent saltwater intrusion into water intake (Kelani (Kelani intake water into intrusion saltwater prevent to Ambatale at necessary is flow /s /day) 3 3 /day) 3 /s is required for salinity Additionally control. there are several other schemes upstream of Colombo that 3 /day (around 12% of the total piped water supply). As shown in table 3, the total numbers of recorded 3 At present there are no water supply schemes relying on groundwater in the Colombo district. However, In total there are 10 major surface water supply schemes operating within the Colombo study area using : : /day (10% of As total shown supply in in table Gampaha 3, - the Panabokke total and numbers Perera of 2005). The amount of groundwater use by the piped water supply schemes within the Kandy region is estimated 3 Groundwater use (individual) (m Groundwater on groundwater (%) Population relying well number Registered deep borehole Ground water for piped supply (m Ground water : Note; * district values Surface water registered deep groundwater abstraction wells in the Colombo and Gampaha districts are only 342 and 890 respectively making a total of 1,232. In comparison to other cities in Asian the region, this number is very small, but the population relying on shallow groundwater within these two districts is estimated as 34.8% and water coverage. Individual domestic use percentages are mainly due to poor pipe is estimated in the Colombo study area 75.4% respectively. These high to be consuming approximately 85 million cubicrecording the groundwater metersuse, only estimations ofcan be made. groundwaterFurther, it should be noted that annually.this estimation excludes Here, as groundwater thereuse by houses that is already have noa pipe water systemconnection and use groundwater ofas a supplementary source. Since the percentage of domestic consumers with a piped source, water especially supplyin peri-urban andareas, is usingbelieved to groundwaterbe high asand also a increasing, supplementarythe above estimations may be lower Ganga Basin – our 1999). study However, analyzing the recent Ambatale salinity estimates problems that at a minimum flow of 30 m volume taken from the Labugama and Kalatuwawa from tanks,the Kelani all River. However, remainingas the Colombosurface water supplywater intake requirementsat Ambatale is ocean onlyareconfluence, less 16 extractedthan km 15 upstream m above from mean the sea level, it is estimated that unless m a 33 a of salinity minimum a barrier constructed, across the river is A A summary of potable water use in the 2000-2001 period is component is revenue water nearly given35-40 (NRW) % of making the it total a water significant supply, component in both in table 4 below. As given in the table, the values of the other countries in the region. non- These percentages are very high compared to NRW the study areas. rely on Kelani water for their water supplies. (2) groundwater consumers are estimated to be using approximately 15 million groundwater consumers are estimated to Kandy than the actual groundwater use. Colombo Colombo surface water. The annual supply from these schemes in 2001 is estimated as 286 million at 8,567 m the amount of groundwater used in piped water supply schemes in the in the Colombo study area 5,859 m is deep groundwater abstraction wells in the Kandy district is 1,754, a much higherFurther, the percentage value of the than population relying in on thegroundwater in Colombothe district region.is almost 52% and individual domestic

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 117

/day) 3 NRW NRW 22,928 243,956 (m /s in June. Also, 3 41,000 234,000 /day) 3 /s), a large amount of surface water from 3 804 6,970 . Groundwater (m Groundwater . Further, even though the total irrigation requirement /year 5,546 3 11,151 m Deep Shallow Shallow Deep Domestic Industrial Domestic /s flow is required as environmental flow to satisfy the downstream 3 . This was mainly to upgrade the existing supply in the region and to /s in February and March, and the maximum at 36 m 3 /year 5,972 3 /day) 3 158,445 m Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in /s (but within the study area is only 0.4 m 3 /year of water (2001). This entire surface water demand is extracted either from the 3 Surface water (m Surface water 36,679 380,248 Domestic Industrial Domestic Table 4. Domestic and Industrial Water Use within the study areas the Use within Water and Industrial 4. Domestic Table

Although : there have not been many studies done, in a study under the “Kelani Ganga Basin Study – 1999,” In contrast to Colombo, there have been few attempts in Kandy to estimate the groundwater potential in the -maps, geological and geophysical studies, topographical map studies, investigational drilling, pump testing, etc. etc. testing, pump drilling, investigational studies, map topographical studies, geophysical and geological -maps, Colombo (2001) Kandy (2000) : : In Kandy there are only 7 major surface water supply schemes operating within the study area. These schemes

Mahaweli River is diverted at Polgolla to northern parts of Sri Lanka for irrigation purposes. The minimum diversion requirement at Polgolla is estimated at 14 m than 100 l/min, 16% between 100-1000 l/min, and only 3% greater than 1000 l/min. than 100 l/min, 16% between 100-1000 l/min, and only 3% greater than 1000 Kandy Colombo the sustainable aquifer yields within different hydrogeological settings of Colombo study area, especially in the Kelani basin have been forecast by the Danish Hydraulic Institute. The estimated yields during this study are shown in table 3 below. 2.3 Resource Availability 2.3 Resource (1) Groundwater requirements below the Kandy study area. Kandy Mahaweli main river or from its tributaries. Additionally in November 2006, the pipe water distribution to Kandy was further increased by another 19 million in addition to these requirements, a further 4.2 m distribute over 25 million m replace some of the existing problem-prone groundwater supply schemes. With this addition, the current surface water extraction from Mahaweli has increased to 44 million in the Kandy district is only 1.6m Furthermore, in 1988 another similar investigation has been done in Kandy to determine the suitability of geophysical investigation methods for assessing the aquifer yields in the region. However, the conclusion of both these studies was for local conditions in Kandy that none of the methods used were suitable region. During the 1980-1984 period, one such studyLandsat was done with foreign assistance through aerial photos and Since there were no reliable estimations for aquifer yields available, out an the attempt aquifer was behaviormade in during three this of study the to divisional find secretariat (DS) areasand Udunuwara, of with thethe help Kandy of studyavailable information. area,In this the analysis Harispattuwa,the borehole logs were studied for construction yield with the yield variation by rock type on which the well was constructed. The obtained comparative results are shown in Table 4 and 5 Table for the borehole yields and borehole success rates According respectively. to this comparison, it was observed that most of the analyzed wells had yields of less than 100 l/min; in fact 81% were less

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 52 76 50 53 42 25 50 37 33 80 00 (%) 158 156 Dec. Success 234 297 Nov. - /day) 69 29 3 248 482 716 206 156 122 747 148 Yield (m 217 345 Oct. 4 4 8 3 5 5 37 28 15 19 No. 135 187 233 Sep. 211 224 Aug. in the month of June at Hanwella. 3 m Jul. 299 275 Rock type million Biotite Gneiss Gneiss Biotite Hornblende Charnockitic Gneiss Garnet Biotite Gneiss Granitic Gneiss Biotite Gneiss with Calcite Calcite Gneiss Marble Charnockite Gneiss Biotite Charnockitic Gneiss Feldspathic Quartz 224 373 Jun. in February (table 8). 3 Table 7. Borehole Yield and Success with Rock Type with Rock and Success Yield 7. Borehole Table m 129 286 May million 71 162 Apr. 20 (%) 46.67 33.33 /year) 2 Available Surface Water in Study Areas in Study Surface Water Available Harispattuwa /km

98 47 3 0.37 0.91 0.73 0.66 0.73 0.55 Mar. m 6 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Estimated yields (×10 68 47 Table 8. Table Feb. 2.7 (%) 13.6 83.33 Kundasale in July and lowest of 47 94 89 3 Jan. Borehole Yield Borehole m ) 3 80 1.7 (%) 18.3 Table 6. Table million was observed in February and a maximum of 373 Udunuwara 3 m Aquifer Type : The Kelani River is the major surface water source used in the Colombo. As discussed earlier, the existing Flow (million m Monthly Average Average Monthly The Mahaweli River is the major surface water source for the Kandy study area. Although there are several Mahaweli at Peradeniya Kelani at Hanwella : Yield Yield million Source: Deparment of Irrigation, Sri Lanka Source: ( l/min) Vesicular laterite Vesicular >1000 0-100 100-1000 Karstic Crystalline Limestone Karstic Crystalline Quartzites Fractured bedrock Clayish sands Gravel/Pebble Table 5. Estimations for Annual Sustainable Yields Sustainable Annual for 5. Estimations Table Source: National Water Supply and Drainage Board, Kandy Supply and Drainage Board, National Water Source: Source: Kelani Ganga Basin Study – 1999 Kelani Source: Kandy of 68 Surface Water (2) Surface Colombo water intake to Colombo is Ambatale, located only at 16 km upstream of the ocean outfall. Therefore the Kelani stream flow was investigated just upstream of Ambatale at Hanwella, analyzing the river discharges discharge fromriver average minimum a analysis, this to According 1973 to below. 8 table in summarized is analysis this 2004.from finding The substantiating this claim with actual data was not possible. substantiating this claim with actual data Further the results in table 7 shows that failure rates in constructionover 50%,in Udunuwarabut comparativelyand Kundasale lessDS indivisions Harispattuwaare DS division. As type shownin the in Kandy figurestudy area3 is previously, biotite the gneiss main(49%). However, bedrockhornblende biotite gneiss, charnockiticbiotite gneiss and granitic gneiss are present in reasonable percentages as gneiss,well. Comparing the borehole efficiency (high garnet efficiency means both high yield and high success rates) with bedrock geology, boreholes in hornblende biotite gneiss and in charnockitic biotite gneiss formations give good groundwater. Conversely, poor efficiency is observed in areas with biotite gneiss, charnockitic gneiss, garnet biotite gneiss, granitic gneiss, charnnockite, and marble rock formations. These formations cover over 73% of the total study area in Kandy. Therefore, the ground rock formations around the Kandy region is waterhighly questionable. Since there is no continuous monitoring data available, potential in the hard tributary streams flowing into the main river from Peradeniya to Polgolla, the cumulative discharge from those streams is substantially lower (less than five percent) than the main Similar river. to the Kelani an River, analysis for Mahaweli River flow discharges at Peradeniya Gauging of 299 Stationdischarge between 1964 and 1993 show the highest average monthly

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 119 1995

1990

1985

/hour (Premaratne and Liyanapatabendi, 1994), 3

1980 ar Ye 1975 /hour and 45 m 3 1970 As : a result of the many subsidy programs intended to diversify agricultural Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in 1965 Figure 6. Annual Rainfall Variations in the Kandy Region in the Rainfall Variations Annual Figure 6. Source: Metereological Department of Sri Lanka Metereological Source: 1960 0 0

50

3000 2500 2000 1500 1000 a A m m l l f a ( n i n n r l u ) a : Though a fair amount of rainfall is on record for both the study areas, their seasonal distribution is closely : Similarly the 60 year annual average rainfall in the Kandy study area is 1,841 mm. In addition, the maximum Rainfall

activities, and because of the changes in the rainfall patterns, groundwater use, both as a supplementary source and as a means of cultivating short-term crops during the dry season, has recently become very popular among many farmers in the dry zone of Sri Lanka. For these abstractions, farmers most commonly use either tube-wells (boreholes) or dug in diameter (4 wells. to Dug 6.5 wells m), are are usually fairly manually large excavated, are shallow (4.5 to 12 m), and may or may not be equipped with a motorized pump. These wells, when used for agricultural purposes, are commonly agro-wells in growth the schemes, subsidy NGO-assisted and Government- the With country. the in agro-wells as known is progressing at a rapid At pace. the end of 2000, the total number of agro-wells stood at 50,456, while in 1985, there were only 500 (Kikuchi et al. 2001). This rapid, haphazard expansion of agro-wells without appropriate assessment of abstracting to used are farmers As problems. many create to expected is environment hydrogeological the as such factors groundwater at rates typically ranging between 27 m the groundwater resources either on a local or regional scale. Groundwater user Groundwater Agriculture trends in Kandy (3) Colombo 2,376 is Colombo in rainfall annual average year 40 the data, historical to According pattern. monsoon the with associated mm. Further, the maximum and minimum monthly average rainfall observed in Colombo during this period respectively. and 78 mm in February mm in May was 360 and minimum monthly average rainfall observed in Kandy during this period were 278 mm in November and 68 mm in a closer Further, look at April the respectively. rainfall variations in Kandy shows that the annual rainfalls are following surface water. many uncertainties over the future of This trend raises 6. as shown in figure a decreasing trend, these high pumping rates are believed to be the most likely potential cause of conflicts because of overexploitation of

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 . 9,465 2,803 118,684 . In Sri Lanka, 3 Ground m 2020 200,051 million 58,913 506,325 198,898 Surface Kandy Region 7,129 1,810 115,328 Ground 2010 206,138 46,098 441,971 181,508 Surface 976 6,970 105,621 Ground

Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in 2001 243,956 33,280 380,248 158,445 Surface Water Supply Requirements in Colombo according to Sector and Source Supply Requirements in Colombo Water Colombo Region Table 9. Table /day) 3 Figure 7. Sources for Drinking Water in the Study Areas in the Year 2000 (NWS&DB data) Year Areas in the in the Study Figure 7. Sources for Drinking Water At present in Colombo, the surface water is mainly used for drinking/recreational purposes. Using the According to National Water Supply and Drainage Board (NWS&DB) information, figure 7 below shows : : Usage (m NRW Industrial supply Other Domestic supply Domestic : Surface water in the Kandy study area too is mainly used for a) drinking/recreational purposes, b) diversion/ : As shown in Figure 7, only 38% of the population in the Kandy study area is served with piped water, and of the percentage of people using water different sources for their drinking water needs within the two study The areas. Sri Lankan Government established NWS&DB in 1974 for providing safe drinking water to the population. According to these data, 62% of the population in Colombo study area is served with piped water and of the rest, 36% use protected transfer requirement at Polgolla for hydropower generation and irrigation and c) to maintain minimum flow requirement in the downstream. With the population in the Kandy study area expected to reach 1.04 million by the year 2025, the Colombo access to safe drinking water is interpreted as having a source or water supply satisfying the Sri Lankan standards for drinking water, which are more stringent than the WHO implies standards.that the Thereforewater is within “safe the drinkingminimum required standards water”for drinking.Poor in monitoring, thishowever, especially sectionin of this water raises many doubts on the actual safety individual groundwater extractions, community wells and Colombo Kandy the rest 47% use groundwater and 15% others unsafe water sources, such as streams and unprotected wells. the rest 47% use groundwater and 15% Supply Demands Water (2) Future Source: Statistical Abstract 2005, Department of Census, Sri Lanka Statistical Source: Kandy groundwater and the other 4% unsafe water sources, such as streams and unprotected wells. groundwater and the other 4% unsafe water Present Supply Coverage (1) Present The present (2005) safe drinking water coverage of the country is expects estimatedto increase its investment at in water supply 69%. to achieve Thea safe water Government coverage target of 87% of by the year Sri 2015 and Lanka number of new nearly A projects 100% have coverage been in launched 2025. with local and foreign funding to achieve this target. Total pipe water production in Sri Lanka in the year 2005 was estimated as 383 2.4 Piped Water Coverage Water 2.4 Piped population growth trends in the past, industrialization trends and the NWS&DB 1991 Master-Plan documents, water demand for various sectors within the futureColombo study area The was obtained water estimated. demands are shown According to 8a this in below. Table estimate, even in the year 2020, the major water requirement will be for satisfying The forecasted industrial demand in 2020 will only be around 40% of the 2020 domestic demand. the domestic demand.

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 121 2025 1,451 107,207 Ground 2.0 57.0 16.0 19.0 94.0 2025 2015 2025 18,141 ar Ye 86,336 16,690 Surface 2005 . 1.5 55.8 15.8 18.0 91.0 2015 1,684 98,415 2000 Ground 0 0 0 0 0 2015 28,068

20 80 60 40

1000 a s ' 0 0 0 n o i t l u p o P d e v r e S 61,029 15,157 Drinking Water Coverage(%) Drinking Water 1.0 54.0 15.5 17.0 87.5 2005 Surface 0 202 804 31,300 010 Ground 5 2 0.5 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in

38.0 15.0 15.5 69.0 00 2000 2000 22,928 ar Ye 5,972 0 2 36,679 00 Surface Water Supply Requirement in Kandy According to Sectors and Sources to Sectors According in Kandy Requirement Supply Water Figure 8. Future Water Supply Coverage in Colombo and Kandy Figure 8. Future Water Colombo Kandy 5 2

199 /d) Table 10. Table 3 Total 1990 Table 11. Mode of Safe Drinking Water Coverage in Urban and Rural Areas of Kandy District Coverage in Urban and Rural Mode of Safe Drinking Water 11. Table Master Plan documents of the NWS&DB details the proposed future pipe water supply coverage plans within within plans coverage supply water pipe future proposed the details NWS&DB the of documents Plan Master Mode of supply : Usage (m According to figure 8, which was based on the Kandy water supply Master Plan Document of 2001, pipe water coverage coverage water pipe 2001, of Document Plan Master supply water Kandy the on based was which 8, figure to According

Other Pipe borne Tube Well Tube Protected Dug Well NRW Industrial supply Domestic supply Domestic 0 0 0 0 0 : Source: National Water Supply and Drainage Board, Water Supply Master Plan for Kandy 2001 Water Drainage Board, Supply and National Water Source:

3,00 2,00 4,00 1,00

n o i t a l u p o P d e v r e S s ' 0 0 0

Source: National Water Supply and Drainage Board, Water Supply Master Plans for Colombo 1991 and Kandy 2001 Water Supply and Drainage Board, National Water Source: the two study areas. The planned supply coverage by year 2025 proposed in the Colombo report is shown in Figure 8. According to the proposals, piped water coverage will increase from the present 2.67 million people to 3.47 million In addition, the safe drinking water coveragedistrict is given in According table to 11. augmentationsthese data, the highest coverage increase of 19% plannedis expected from pipe water during the nextaugmentations. 20 yearsBy thewithin year the2025, Kandy10 new piped surface waterwater treatmentschemes schemes areare under foreseenconstruction there:to the be North constructed.of Kandy Town AlreadyProjectand northern to parts twocover of the the largeregion, central and the South of Kandy Town Project to cover the western and southern parts regions. of However the the expansion in groundwater use forecasted for the future is small as the expected increases in tube estimated only at 1.0%-3.5% respectively wells and protected dug wells supply is Kandy from the present 0.31 million people to 0.395 million people by the year 2025. within the Kandy study area will increase people by 2020 in this study area. Future Water Supply Developments Water (3) Future Colombo for drinking purposes. Kurunegala District estimated future potable water demand in Kandy is tabulated in table 10 below. In addition to these requirements, the Kandy Water Supply Master Plan document proposes diverting surface water from Mahaweli River to the adjoining

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 are classified as failures. According to this classification, the l/min /day, thus making them suitable only for small-scale water supply systems. thus /day, 3 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in 3. Issues of Groundwater Management of Groundwater 3. Issues : Most of the quantity problems experienced in this study area occur in the coastal aquifers, vesicular laterite The general opinion among many officials involved in groundwater development in Sri Lanka is that the exact reasons for most of the borehole failures are not commonly known because one would require a borehole camera to investigate, and this facility is not available in though Further, the there country. are various other opinions concerning the country’ s groundwater issues, lack of data and the wide range of abstraction across many different aquifer environments make the problem analysis very complicated. Hence in this section, the quantity and quality-related issues experienced in the The other major groundwater extractions are coming from semi-confined bedrock aquifers. These semi-confined rock aquifers are used in high-volume requirements such as industrial activities, and by According water-supply schemes. to and laterite aquifers are only available in the Colombo study area and not in the Kandy study area. and laterite aquifers are only available in the Colombo study area and not in the Colombo aquifers or in semi-confined rock aquifers.using Invery productiveaddition, alluvial aquifers therealong the is river a and tributarysignificant banks. In exploitationamountthe iscoastal seen regionsof as of groundwatera Colombo, major over- threat toabstraction the sustainable use of its Ragama). These thin, coastalfreshwater lens aquifers that sandfloat on saline water aquifersare often contaminated with (e.g.,saline water due waterto supply system in excessive abstraction, especially during prolonged droughts. In regions of vesicular laterite aquifers, some are productive,highly and therefore they are commonly usedabstraction that formostly occurs medium-scalein these laterites located pipedaway from the waterflood plain supply results in the schemes.lowering tableof the The(industrial water excessivezone in Ekala). When these aquifers are used localized groundwater table excessively,depletions affecting the groundwater thewells in the aquiferssurrounding areas. These coastal aquifers themselves are subjected to 3.1 Quantity-related Issues study areas are discussed in a more generalized form. borehole wells in Kandy is below 144 m The history of well construction in Sri Lanka itself is indicative of the success rate. The NWS&DB is responsible the for rural and urban water supply for domestic use and is currently the largest organization that develops in groundwater the country. According to the well construction unit of NWS&DB, production and hand-operated wells tube thatwells that yieldyield less less than 4 than 20 l/min Over the past 30 to 50 years, there haveSri beenLanka. threeThey mainare thestate Water agenciesResources Boardinvolved (WRB),in and Nationalgroundwaterthe Agriculture Water DevelopmentSupplydevelopment Authorityand (ADA).in Drainage In addition,Board a (NWS&DB)few private projects drilling have also been engaged companiesin the investigation and development and of this resource. donor-fundedIn terms of monitoring and data collection, these organizations collect data primarily for their own use, although some is shared with other agencies and some is released to the public. this However, collected data is mostly limited to deep wells. In most cases, the recorded information is restricted to the drill log, the initial water levels, and the groundwater-related continuous no initialis there this, of Because companies. drilling private by constructed wells on available water quality. There is no information monitoring data available, and hence there is no means of controlling the adverse impacts from the developments taking areas. place in recharge success rate of wells during the construction stage is currently about 80%. Some wells go dry in short time while others have a smaller reduction in yield and continue at a lesser yield. Usually a well will achieve five a to steady eight state years. after If about a well fails to continue to function at the rates mentioned above, well. it Usually will the be average classified success as rate a achieved failed at this stage for the whole country is about higher 65%. for This dry-zone rate wells is maintained by slightly the which community, stay at about 70%. The lower success rate achieved in wells maintained by the local governments is attributed to poor Addition maintenance to and this over-abstraction. data, our investigations showed that in the Kandy area, the success rate was only around 50%, much lower than the national average, even as early as at the drilling stage for deep boreholes. Further, the yield at drilling in majority of these

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3

123

0 l u - J 5 n

mi

0 n a J - 5 3

/m

0 - l u 4 J

ed

a J 0 - n 4 mp

Pu 0 - l u J /day. 3

3

ty

ti

J 3 0 - n a

0 - l u J 2 Quan

2 0 - n a J

me

x

0 - l u J 1 Ti ma

/day, /day, which is also using two borehole wells. At the test

3

3 3 0 n a J 1 -

/m

0 l u - J

0 ed

a J 0 - n 0 mp

Pu

9 - l u J

9 ty

ti

J a 9 - n 9 an

Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in

Qu

9 l u 8 - J

n J 9 a 8 - 0 0 0 0 0 0 0 0 0

80 70 60 50 40 30 20 10 Figure 9. Groundwater Pumping Rates in Owissa (Kandy study area)

/ g / m e t a R i m u P ) day ( n p 3 : Most of the quantity problems experienced in this study area occur in the semi-confined bedrock aquifers. In

Source: National Water Supply and Drainage Board, Kandy Supply and Drainage Board, National Water Source: pumping, the recommended yield for this borehole field was in excess of 1,500 m was in excess of 1,500 borehole field pumping, the recommended yield for this Considering all the above information, the most common formations can be listed as: failure modes in the boreholes constructed on hard rock Using the limited data available, monthly minimum and maximum extractionsHarispattuwa DS fromdivision at one Owissa was of analyzed. theThe obtained boreholeplot is stationsshown in in figure 9. According to the available data, the maximum pumping rate is around 500 to 600 m scheme. these failures. Kandy the NWS&DB, most of these deep, hard rock abstraction wells have experienced either a rapid lowering of their water levels or decreased yields or both. Since there is no continuous monitoring being done, the only information available on these boreholes is the initial drill log, initial water quality, and test pump results. Hence the actual causes for these failures are largely unknown. In such failures, the usualborehole in practice the and vicinity, in adoptedsome cases, only by a few the meters away authoritiesfrom the existing iswell, to toreplace the drillproblematic borehole.another Thisnew has been possible since the groundwater resources within a very in close Many proximity. officials hardinvolved in groundwater rock abstraction suggest that formationsa poor understanding of are highly variable even the resources and poor preliminary investigations, inadequate monitoring, and poor maintenance are the main causes for this region too, the current problems associated with these rock aquifers are very much localized. In addition, there is a significant amount of groundwater abstraction using very productive alluvial aquifers banks. alongPersonal communication the shows river that there and are tributary a number of groundwater schemes in the Kandy study area as such the Kondadeniya scheme, Gohagoda scheme, Kulugammana scheme, Hedeniya scheme, scheme,Yatihalagala etc., that have been abandoned due to water depletions. Furthermore, a Bokkawala, numberAnkumbura, AlawathugodaAkurana-Welekade, of and schemesRajapihilla schemes such are as suffering Ampitiya,from lower Galhinna, yields. All of these schemes were initiated in the early 1980s and, at present,deep aquifers almost are allfailures and schemes the water operating supply usingis restricted hard to few rock hours a day on a few days region, per unlike week. in In Colombo, the the Kandy success of drilling new bores in the vicinity as a solution had only limited success, in as, most cases, water had to be taken from places far away from the existing intake boreholes, making the supply very expensive. Even these new borehole locations also had run into many problems as they were in hard rock formations. a massive Consequently, surface water facility to replace the groundwater schemes was constructed in November 2006, and now some of the schemes closer to the Mahaweli River—Kondadeniya, Kulugammana, Yatihalagala, Gohagoda, Rajapihilla—that previously operated using groundwater have been replaced by the water from this new surface water

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3

Co 0 0.02 0.01 208 (mg/l) Sulphate Cd 0.00 0.00 . 0 P 0.16 (mg/l) Pb 0.04 0.01 4 0 (mg/l) Nitrate Cu 0.03 0.01

4 2 0 Cr (mg/l) . 0.13 0.03 Free NH Al 0 5.62 0.37 13 (mg/l) T-Iron T-Iron Ni 0.1 0.21 8 7 pH Ag 0.58 0.05 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Table 12. Groundwater Quality in Colombo 12. Groundwater Quality in Table 12 800 (mg/l)

Chlorides Mn 0.92 0.09 Concentrations of Heavy Metals in the Groundwater in Southern Colombo

77 EC 1170 Fe 1.1 9.27 (µC/cm) Table 13. Table Though legal provisions are available with the Water Resources Board of Sri Lanka (WRB) to control Metal : Similar to Colombo area, there is almost no continuous groundwater quality But, monitoring done in Kandy either. Parameter

Ave. (mg/l) Ave. Min. Max. (mg/l) Max. : Source: Gunawardhana et al. in 2002 Gunawardhana Source: as a test pumping, the storage can exhibit a higher yield than the actual yield. yield than the actual can exhibit a higher the storage as a test pumping, making the yield drop drastically can drop the water levels considerably by excessive pumping Lanka shows that not all wells recovered even after repeated flushing. recovered even after that not all wells Lanka shows such situation a In yield.” “safe so-called a determine to difficult very is It over-exploitation. to due deplete gradually iii. Slow recharging potential in hard-rock/crevice aquifers. potential in hard-rock/crevice aquifers. iii. Slow recharging In some aquifers, siphon action within the fracture iv. zone can bring substantial water volumes, and its failure caused v. v. to take timely and adequate measures. Lack of information concern in the shallow groundwater is contamination due to coliform. In addition to the above water quality measurements, there have been a few locations, regular or at intervals regular at tested been not have they Although years. few last the over wells qualitygroundwater measurements taken for shallow some trends can be observed with these measurements. most Generally, of these quality tests are made on request and quality main the shows that monitoring This schemes. supply water piped for community used boreholes of the for some Kandy groundwater pollution, there is no mechanism available with the WRB to monitor the groundwater quality continuously. groundwater pollution, there is no mechanism WRB available to with monitor the the groundwater quality continuously. Random or quality data is limited to the initial measurements monitoringdone duringis notdeveloping mandatory the either. resourceHowever, andthe NWS&DBthat qualitymonitor groundwater qualityunder them. Based on the inrandom quality measurements available, watertable 12 below summarizes supplythe general groundwater schemes quality in the Colombo study area. The available exceptquality for datahigh doesiron notcontent raisein somemany locations.concerns However, in sincespeciallydeep therelocatedgroundwater, arein themany suburbansmall- parts and of medium-scaleColombo that industrieshave no properwater contamination problem wastewatercomplaints arise disposalthere. In one systems,such case, manyan investigation shallowfor heavy metal concentrations in shallow groundwater was done by Gunawardhana of et Colomboal. have in abandoned2002. theirThis drinkingstudy wells foundmainly thatdue to manyexpected, most problemsof in the ofindustries southernin odorthis area andtend partsto taste. discharge untreated or It partially also treated effluent into revelednearby drains, that, as polluting The the heavy groundwater. metal concentrations measured during this study shows that the area groundwater is high in Ag, Al Fe, Ni concentrations. The Mn, and summarized average and maximum concentration of heavy metals is tabulated in table 13 below in well waters detected during this study Issues 3.2 Quality-related ii. As the ii. storage in a hard rock aquifer is limited, this type of aquifer will exhibit higher yield at construction but i. Clogging the fracture zone/path of borehole wells, thus failing to recover even after flushing. Past experience in Sri Colombo as there are many borehole wells constructed in the suburban areas in based Kandy, on the quality measurements taken in these locations during construction, table 14 below summarizes the groundwater quality in the suburban areas. According this data, hardness, iron and nitrite are of concern in some locations in southern, western and eastern regions. Hardness as high as 1,125 mg/l is observed. Further, total iron concentration of 18 mg/l, nitrites 128 mg/l and sulphates of 500 mg/l is good. notable point with these results is that the groundwater quality in the northern areas is found to be very A observed.

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 125 - - P 0.2 (mg/l) - F 0.9 0.65 (mg/l) 1.5 4.4 Mn 0.5 (mg/l) 48 3.5 128 (mg/l) Nitrite f. 197 1,096 1,125 (mg/l) Hardness 50 0.5 500 (mg/l) Sulphate 18 4.8 15.2 (mg/l) T-Iron T-Iron Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in pH Groundwater Quality in Kandy (Maximum Observed Values) (Maximum Observed Quality in Kandy Groundwater 4.6 - 7.9 5.8 - 7.5 5.6 - 8.5 ) ranges from a low of 0.011 USD for the first 10 units to a high of 0.7 USD a unit for units 3 Table 14. Table EC 790 705 2,190 (Mhos/cm) Parameter North South East Source: National Water Supply and Drainage Board, Kandy Supply and Drainage Board, Water National Source:

The two most common methods adopted to clean up wells soon after the tsunami was to empty the contaminated water either by means of pumping or by manual cleaning and restorationdisinfection efforts using encounteredbleaching a powderrange (hypochlorite).of problems, These as most Most of ofthe cleaned wells were thereported to remain saline, peopleeven after repeated cleaning and involvedemptying. In addition, wells lacked specialized knowledge. potential caused of pollution sources other from of contaminants presence the and process, cleaning the during collapsed conductivity levels of over 3,000 µS/cm. Sri Lanka has a coastline of approximately 1,660 kilometers. This coastal zone is very and diverse,estuaries, fringing and and offshore containsreefs, mangrove lagoonsswamps, sea-grass beds, salt marshes, beaches, sandy spits, rocky the provided the main domestic water source for shores have traditionally and dune systems. Shallow groundwater wells settlements throughout the entire coastal areas. Asian The tsunami on December 26, 2004, hit the Sri Lankan coastline with various degrees of impact, but the eastern, northern and southern coastlines in particular were devastated (ADB, 2005; UNEP, 2005). In Sri Lanka alone, over 40,000 people were killed or went displaced by missing, the flood and waves many and the thousands extensive property were damage. In addition, most of the natural ecosystem along the coast was destroyed and complete infrastructure facilities in this coastal belt were totally devastated. Immediately after the tsunami, it was estimated that over 60,000 groundwater wells (mostly dug wells) zone, and throughout in some the places almost affected up coastalto 1.5 kilometers inland, had been damaged or destroyed. Many of them were left unable to provide water that was fit for human consumption or even for bathing or washing (ADB et al., 2005; UNEP, 2005). The damage to the wells ranged from filling themfrom the withstagnant saline debris,water collected sewagein local and depressions. saltwaterMany water tosupply schemes salt catering waterto domestic were intrusionneeds also affected due to breaches in the water distribution pipelines and the filling of wells with debris and saltwater. In addition, the characteristics and quality of soil and water resources in the of coastal seawaterareas overwere changedthe by soil the surface,flow the stagnation of saline disruption and and loss possiblyof the pollutedcoastline. According to watera study in by Jayaweera local et depressions,al., 2005, a andfew days the after contaminated wells the had tsunami, COD the levels of 128 mg/l, total and fecal coliform levels exceeding 30 and 7 CFU/100 ml, and 3.4 Effects of the Tsunami on Coastal Groundwater 3.4 Effects of the Tsunami The obtained results show that a majority of consumers with pipe connections trust the pipe-borne especially water, for drinking and in-house use. However, a substantial percentage of respondents are using groundwater as source. In addition an to this, alternativefeeling many is consumers’ that groundwater is safer than the piped water Further supply. to this, an effort was made to ascertain the future trends in groundwater use by allocating different weights (both negative and positive weights with average 0) for key questions asked in the questionnaire based on According their importance. to this analysis, a net value of Therefore it +1505 can was be obtained. predicted that there will be an increasing trend in this may depend on the water tarif groundwater use in the future, although conditions, and groundwater use were also questioned. In total over 375 samples were collected. conditions, and groundwater use were also The piped water tariff in Sri Lanka has increased over tenfold during the of past a twenty unit year of period.water (1 Presently m the cost 3.3 Future Groundwater User Trends in Colombo Study Area in Colombo Study User Trends 3.3 Future Groundwater consumed above 40. As such tariff increases surely reduce the piped water consumption, consumers may more groundwater, which tend is to freely available. use Therefore, to ascertain perception consumers’ a questionnaire survey was conducted in the peri-urban areas north of Colombo with the primary objective of studying the effect of the recent tariff sanitary increase on water consumption and on groundwater use. In addition, water use pattern, opinion on groundwater,

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 77.7 74.7 /s. Analyzing the 2025 3 152.46 28.9 77.7 2020 106.6 77.7 61.3 2015 /month) /month) 139.04 3 3 104 26.3 77.7 2010 77.7 50.3 2005 128.03 Water demand/(million m Water demand/(million m Water 24.5 77.7 2001 102.2 46.4 77.7 2001 124.2 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Minimum Surface Water Requirements to Satisfy Future Demand in Colombo Requirements to Satisfy Future Minimum Surface Water Table 15. Table The estimated river flow requirements to satisfy the full development water supply demand and planned : Total required flow Total Water demand Water Environmental flow to salinity control Water demand Water Environmental flow to salinity control required flow Total Full Development Demand Planned supply demand 4. Issues relating to Alternative Water Resources to Groundwater Resources Water Alternative to 4. Issues relating water supply demand in Colombo study area is tabulatedavailable inon tablesalinity 15control below. at ThoughAmbatale (riverthere waterare intake),previous our(environmental studyinvestigation flow) requirementdata for showssalinity controlthat downstream the of Ambatale minimumis estimated river at flow30 m Considering the past 40 year Kelani River discharges Ambatale, at an analysis was done to determine the reliability of daily available average flows in the river to satisfy the future expected demand in the Colombo The study obtained area. reliability percentages for this case are tabulated in table 16 The below. reliability values show that Kelani River flow can satisfy the Colombo study area year 2025 full development demand 79.7% of the time and planned supply demand available Kelani flow data given in table 8 with the required minimum demands in table 15, it is obvious that satisfying demands, especially during dry weather low flow periods, can create salinity problems at Ambatale the water treatment plant. During recent years on a few occasions, Ambatale the water treatment plant had to be closed due to high salinity levels. Knowing this, a salinity barrier (barrage) across the river has been proposed. However the estimations in table 15 have not taken into consideration any salinity controls in existence. Therefore, if a salinity barrier is constructed, the Ambatale will be less than that considered here. of requirement downstream minimum environmental flow in year 2020 by 90.8% of the time. Colombo supply demand (what is planned in the water supply Master Plan Documents) for year 2025 was estimated. supply demand (what is planned in the Since there are many concerns withrequirement in thethe two study areas existingis to be satisfied with groundwatersurface water, the required minimum river runoff volumes sources,to fulfill assuminga) the full thedevelopment water entiresupply demand level future(water provided waterto entire population) supplyand b) planned water water issues and the possibility of rainwater harvesting as an alternative water source for domestic use. water issues and the possibility of rainwater 4.1 Surface Runoff Issues As explained, both the study areas of Kandy and Colombo are blessed with plenty of rainfall when and one surface considerswater. But, their variations over space and time, further analysis is during requiredthis study rainfall and surface to runoff data in the ensuretwo study areas were sustainability.closely investigated to identify Hence,the surface The guidelines include short-term as well as long-term measures. as well as long-term include short-term The guidelines health hazards that previously did not present a significant problem (Jayaweera et al., 2005; Villholth et al., 2005). These These 2005). al., et Villholth 2005; al., et (Jayaweera problem significant a present not did previously that hazards health experiences made very clear the necessity of a well-coordinated, integrated plan to effects restore of the the tsunami and groundwater to implement relief after measures. In the this regard, the IWMI, through some monitoring (Villholth et al., 2005) has suggested a set of possible guidelines to follow with respect to the cleaning of wells after a tsunami.

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 127 /s, in 3 /s. 6.7 3 93.3 36.3 10.9 53.9 2025 110.9 79.7 68.8 70.6 2025(%) 2025(%) 3.6 93.3 36.3 10.9 50.8 2025 107.8 90.8 2020(%) ater Demands in Kandy 6.0 93.3 36.3 10.9 53.2 2015 /month) /month) 110.2 3 3 82.4 69.3 71.1 2015(%) 2015(%) 3.1 93.3 36.3 10.9 50.1 2015 107.1 91.1 2010(%) 5.4 93.3 36.3 10.9 52.6 2005 109.6 Water demand/(million m Water Water demand/(million m Water - 84.9 69.7 2005(%) 2005(%) 2.0 93.3 36.3 10.9 49.2 2000 106.2 5.2 93.3 36.3 10.9 52.4 2001 109.4 91.8 2000(%) 72* 85.8 69.8 2001(%) 2001(%) Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in

/s and the minimum diversion requirement through the Polgolla tunnel is 14 m m m 3 m m minimu minimu Minimum Surface Water Requirements to Satisfy Future Demand in Kandy Minimum Surface Water minimu minimu Percentage Reliability in Mahaweli River to Satisfy the Future W Percentage Reliability of Kelani River to Satisfy the Future Water Demands in Colombo the Future Water River to Satisfy Reliability of Kelani Percentage

River Table 17. Table Demand Planned supply demand Full Development Demand Table 16. Table The estimated river flow requirements to satisfy the full development water supply demand and planned Table 18. Table Diversion water at Polgolla maximum Diversion water at Polgolla maximum Planned Supply Demand Planned Supply Full Development Demand Full Development Water demand Water Environmental flow maximum required flow Total Full Development Demand Planned Supply Demand Water demand Water Environmental flow maximum required flow Total

: * Year 2000 demand * Year

Analyzing the available Mahaweli discharges given in table 8 with the required obvious that satisfying the demands, especially during dry weather low-flow periods, can be minimuma major issue at present and demands in table 17, it is also in the future. Hence, considering the past 40 years of Mahaweli River discharges at Peradeniya, done to determine the reliability an of daily available average flows analysisin the river to satisfying the future was expected demand at The Kandy. obtained reliability as a percentage for this case is tabulated in table 18 The below. reliability values show that Mahaweli River flow can only satisfy the diversion demand at Polgolla and the based analysis same the Kandy Further, time. the of 70.6% demand supply planned and time the of 68.8% demand study development area year 2025 full on average gives monthly the discharge lowest reliability of 32% during February and maximum of 100% in November. Therefore it is vital to use the existing reservoirs at both upstream (Kotmale) and downstream (Polgolla) to control the flow to meet the future demands. February and March and the maximum diversion requirement through the Polgolla dam in June is 36 m through the Polgolla dam in June is and the maximum diversion requirement February and March Kandy water supply demand in Kandy are tabulatedvariable depending on inthe demands Tablein the 17command areas. According to below.the NWS&DB “Kandy Here District Supply Water the irrigation Developmentrequirement Program” of 2002 at (Master PolgollaPlan Document), theis minimum a recharge requirement (Environmental through Flow)the Polgolla dam is 4.2 m

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 , and 20 mg/l for COD 5 million tons are applied as fertilizer is estimated to 4 million tons to rubber, respectively (Danish The other major setback using the surface million tons and 845 : water sources in the pollutiontwo studyissues. Theareas water comesqualityKelani Riverfromvariation was analyzedof theat severalupstream locations and bothdownstream of Ambatale, as in indicatedfigure 10. The rapid development occurring in this region during the last two decadessubstantial is contributing pollution a load upstreamto the areaKelani of River.the AmbataleThe with intake urbanis congested centres, lands. According toindustries the Danish Hydraulicestimations Institutes’and in 1999,agricultural the urban pollutantdry season ranges loadfrom 150 – 650 duringkg/day of BOD. The urban load and per capita waste higher generationin the downstream of the Ambatale isriver intake. much The total load is estimated to be about 4,000 kg/day of BOD below the water intake. The major wastewater Colombo generating industries upstreaminclude raw rubber factories, textile industries, beverage of the river factories,intake rubber latex factories, milk food industries,steel manufacturing factories, plywood factories, ) and chemical oxidation demand (COD) levels at Ambatale and 5 million tons/year, of which 4,000 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in million tons to paddy and 500 and 650 million tons and 1,920 ater Quality Monitoring Points in Kelani River ater Quality Monitoring Points in Kelani River /COD indicate high industrial waste disposal. Further, the observed levels of dissolved Cr and dissolved 5 W Colombo . Figure 10 fertilizer manufacturing factories and industries within the Biyagama estimated Exportto discharge about Promotion1,000 kg/day Zone. of TheseBOD into industriesthe Kelani River. areThe petroleum refinery, chemical industries (soap, detergents, and pharmaceuticals) and Lindel industrial estate downstream Ambatale of intake the discharge about 2,000 kg/day of BOD (Danish Hydraulic Institute, 1999). Referring to the land usage in the basin, it is expected that the run-off of fertilizer, from tea lands in the upper catchment and from rubber and paddy lands in the the principal mid-catchment, source is of nutrients into the The river. current application of Nitrogen and PO periods having decreased all over the country (Ratnayake and Herath, 2005). The chloride content shows high variations, especially in the lower reaches. The main reason is seawater intrusions as a result of low river flows and sand mining. Occasionally this saline Ambatale water water even supply reaches intake the during prolonged droughts and, as mentioned, interrupts the water supply to the Colombo area. Therefore, this saline- water intrusion can be a major problem in the future as many recent studies have shown that rainfall, compared to few decades back, has significantly reduced, with the lengths of the dry periods having increased and the lengths of wet too. Recent water quality in the river is tabulated(DO), 5-day inbiochemical Table oxidation16. demandThe (BOD data show heavy pollution. The dissolved oxygen Hydraulic Institute, 1999). Source: Hearth and Amerasekara, 2004 Hearth and Source: 4.2 Surface Water Quality Issues Quality Water 4.2 Surface downstream of Ambatale were often in excess of the Sri Lankan inlandor for drinking surfacewith complete watertreatment (current standardstandards are 5 requiredmg/l for forDO, 4 bathingmg/l for BOD respectively). Further, in most tributaries and the lower river estuary very low DO values (occasionally below 1 mg/l) and low BOD Pb too the indicate nutrient extensive industrial levels pollution, observed in especially the in the estuary area. However, river are smaller than anticipated considering the loads of applied fertilizer in the catchment. Nonetheless the available nutrient concentrations are far more adequate for eutrophication to 1999) occur and (Muller, periodic algal blooms were observed in the shallower areas, Also, the especially in observed stagnant high waters coliform during low-flow periods. counts well over 15,000 CFU/100 ml in almost all monitoring stations show the high degree of urban sewage discharge, be about 6,900 to tea, 2,000 million tons and 370

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 129 —is 2 - - 0 5,083 3,702 11132 E-Coli (cfu/100ml) 230 – 16,000 400 – 16,000 800 – 16,000 - 3 4 - 0.11 0.03 0.03 0.02 PO (mg/l) 0.01 – 0.1 0.01 – 1.09 0.01 – 0.25 0.01 – 0.13 . Since Maheweli River is the only - - 5 : DO 6.75 6.63 5.53 (mg/l) 2.6 – 8.7 4.9 – 8.3 0.8 – 7.5 adding most of the pollutants into the Mahaweli This urbanized River. sub-catchment that covers a mainly substantial consists part of Kandy City, of commercial and industrial activities, hospitals and urban clusters that have directoutlets sewerageto the stream. The other pollutionconsiderable comes from the largest tributary, Kandy source of surface water available in the Kandy study area, water qualityriver were variationsanalyzed during this instudy this(Figure11). Land cover in the upstream catchment of Mahaweli River is mainly of cultivationforestland, and humantea settlements. Therefore urban wastewater and agricultural runoffthe main sources of pollution from the upstream are area. However, most pollutionRiver tocomes Mahawelinot from upstream from buttributaries The Kandy. of areas fromsurrounding the Peradeniya to Polgolla bring this into wastewater the main river. Of these, the “Meda Ela”— having a catchment area of 19.31 km - 3 - 0.24 0.25 0.26 0.22 NO (mg/l) 0.01 – 0.91 0.01 – 0.67 0.01 – 0.86 0.01 – 0.72 111 20.1 16.4 20.8 COD (mg/l) 10 – 20 10 – 52 10 – 50 4.0 – 46 Mahaweli River 7.5 – 359 Water Quality Data along the Kelani River Quality Data Water 4 3.2 2.26 1.87 3.06 BOD Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in (mg/l) 0.4 – 7.2 0.4 – 5.8 0.4 – 9.2 0.6 – 6.4 Table 19. Table Average Average Average Maximum Permissible Range Range Range Range Average ater Quality Monitoring Points in W Kandy . bridge Victoria Victoria 1 Location Standard Hanwella Ambatale Kaduwela Sri Lankan Source: Hearth and Amerasekara, 2004 Hearth and Source:

Source: Herath, 2003 Source: Figure 1 “Pinga Oya.” Its catchment too is The fairly following urbanized. table, table 20, shows a summary of the past 15 years’ At Peradeniya (before entering the Kandy City limits) the main stream of Mahaweli quality, River yet has therelatively tributarygood water confluence from Peradeniya to Polgolla hascoliform higherand nutrientspollutant are strengths.signs Higherof human amounts waste of contamination. Among the Pinga three Oya tributariesand Meda shown Ela in brings thethe mosttable; polluted the water into the Mahaweli Apart River. from directthe sewerage soliddisposal, waste dumping also takes place in polyethylenethe tributary wastecatchment is areasobserved and atmuddy thesoil, Pingainfiltrationwith and aOya increase greatthe confluence. surface dealwater runoff,of Thewhich will polythenecause flash floods depositsand dryPolgolla shows periods.on the The impact thewater of quality the riverbedat Kandy City region reduceon the quality the of water in Mahaweli intakes. is located downstream of the water supply polluted stream confluence River. Fortunately the most water quality data for Mahaweli River and its tributaries. Given the current and future importance of the Ambatale intake, the construction of a salinity barrier priority appearsto protect to the be water a supply during prolonged dry periods. The flow at intake is currently protected from industrial large effluent discharges by a government policy not to site such industries above sustainability so as to extend the and modelled should be monitored water quality Ambatale. However, the river

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 . 2 . It was 2 - 3 4 2.0 0.20 0.06 0.22 0.18 0.03 PO (mg/l) 0.01 – 1.5 0.01 – 0.1 0.01 – 0.43 0.02 – 2.59 0.01 – 2.85 - 3 10.0 1.42 0.65 2.24 0.95 2.36 NO (mg/l) 0.17 – 4.2 0.08 – 1.3 0.08 – 4.4 0.94 – 6.02 1.32 – 4.97 . 0 50 450 420 3500 1400 E-Coli 10 – 120 50 – 850 9 – 7500 160 – 960 900 – 9000 (CFU/100ml) 5 6.4 5.2 2.4 3.4 DO 3.87 (mg/l) 5.3 – 7.5 4.3 – 6.2 1.0 – 4.6 1.5 – 6.2 1.0 – 4.9 4 8.4 5.2 4.6 3.2 3.06 BOD (mg/l) 0.6 – 6.4 3.4 – 9.2 3.2 – 6.4 3.0 – 4.2 3.2 – 15.8 Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Average Water Quality Data of Mahaweli River, Meda Ela and Pinga Ela Ela and Meda River, of Mahaweli Data Quality Water Average

Average Average Average Range Range Range Range Maximum Permissible Average Range Average 5. Policy Responses and Future Challenges

Table 20. Table Location Standard Meda Ela Maha Oya Pinga Oya Sri Lankan (At Polgolla) (A tributary) (A tributary) (A (A tributary) (A Mahaweli River (At Peradeniya) Mahaweli River River Mahaweli Source: Herath, 2003 Herath, Source: Assuming an average family size of 5 and a minimum water requirement of 40 l/person/day for basic needs, the required required the needs, basic for l/person/day 40 of requirement water minimum a and 5 of size family average an Assuming tank capacity and the necessary roof area for rainwater rainfall years’ harvestingdata The in study Kandy. obtained the minimum weretank capacity as calculated,6,000 l and roof area of taking 134 m into account the past 40 Harvesting Policy and Strategies” was investigated using a questionnaire survey in the Kandy study area. Harvesting Policy and Strategies” was Since there is adequate rainfall available in the alternativetwo study areas,to surface/groundrainwater harvesting water. (RWH) However,can be issuesan acceptance,attractivesuch asetc., rainfallare very reliability,important itsfor thestorage future andsuccess necessity quality,of for rainwaterrainwater consumerharvesting, rainfall harvesting.variations, quality Therefore,of rainwater comparison duringwith drinking this quality studystandards the and the required infrastructure requirements were studied. Further, the future success of the proposed “Rainwater 4.3 Rainfall Issues Also awareness and knowledge on rainwater harvesting were very poor among the respondents. Therefore a program should be implemented to popularize rainwater harvesting within the society Despite the fact that Sri Lanka is blessed with a good andwater time,resource, a when properone managementconsiders its strategyvariations for over its space sustainability recent is warning needed.signals Additionally, pointing thereto haveheightening beenwater aresource numberissues of in Sri are Lanka.increasing as a Competition result of the and highly variable water rainfall and shortagesgrowing demand for are Watersheds water. being degraded resulting in soil erosion, the sedimentation of pollution reservoirs,from domestic, agriculturallandslides and industrialand sources moreis contaminatingserious the floodssurface affecting water andthe and environment droughts.groundwater and and public Water health. Excessive groundwater abstraction is occurring in some longareas, affecting term sustainability. Therefore, in this section,arrangements are analyzed the from availablethe perspective of policyhow they could instrumentsrespond to the andimmediate challenges the posed to existingthe institutional estimated that this storage facility using low cost materials such as ferro cement would cost around 200-250 USD. With peri- four and samples) 22 of total (a areas urban two in conducted was survey questionnaire a findings, these of help the urban areas (51 samples). The results showed that the potential preference in for urban RWH areas is very low but most Also, most people preferred rainwater only for secondary purposes such as people in peri-urban areas are keen on RWH. Although 80% of people with a piped water supply were not keen to harvest rainwater for basic washing, gardening, etc. needs, over 80% of people who do not have a piped water supply were very keen to However harvest one RW. major problem identified during this survey is the extent of available roof area, where over 60% roofs were below 133 m

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 131 . 3 . : In 1974, the NWS&DB was established and given the responsibility to Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in In 1980, the Central Environmental Authority (CEA) was established by an Act : The WRB was established in 1964 by an Act of Parliament to control, regulate and develop— and regulate control, to of Parliament Act 1964 by an in established WRB was The

: of the water resources; trance-river-basin development projects, soil classification, and the hydrological,aspects of the use of lands; and geological and other similar iii. Disposal of sewage and industrial wastes; Preparation of the comprehensive and integrated iv. plans for the conservation, utilization, control and development v. Coordination of v. the activities related to surveys of basic data and other investigations relating to river-basin and control and economic use of water. Any other suitable measures to be taken by the Government for the proper vi. i. Multi-purpose development and use of water resources; ii. water resources; Short-term and long-term provision of

of Parliament for the protection of any portion of the environment against waste Authority discharges. this was Further, entrusted to conduct surveys, to conduct, promote and coordinate research on any aspect of environmental degradation, develop criteria and specify standards inspections to forensure the regulations Again, Act related. this was environmentalamended in 1990 such that many specified large-scale protection and powers projects need necessary toapproval from the for CEA their undertakeconstruction and operations. This included groundwater-based investigations and develop, maintain and provide a safe proper, water supply for public, domestic and industrial purposes and to establish, develop, operate and maintain the necessary wastewater disposal systems in the With this country. Act, the NWS&DB was given freedom to: buy and sell water; develop,the informationoperate, related toand water investigate;supply and wastewatercollect disposal; necessaryowning or leasingdata tangible and conductingand documentintangible research property; related to the supply of piped water and wastewater services, its developments and information including the conservation and utilization of—water resources of Sri Lanka. Further, it was tasked with the promotion, construction, operation and maintenance of water-related schemes (e.g. irrigation, drainage, flood control and hydraulic power, etc.) and the prevention of the pollution of rivers, streams, and other watercourses. the The WRBauthority also to was formulate given national policies relating to the control and use of water resources of the country with the 5.2 Proposed National Water Policy 5.2 Proposed National Water The origins of Sri Lanka’s recent water policy development may be traced back to the recommendations extent some to also given but by commission’ ‘land a as only not role the their perceived who 1985, of Commission Land Presidential as a ‘water commission.’ This commission stressed the need for developinghave identified a many ‘Nationalproblems with Water Masterthe existing Plan’ institutional as arrangement they available for managing the water resources of the Therefore, country. on these recommendations, the Government of Sri Lanka with technical assistance from the Resources Water through the Resources Policy’ Asian Development Bank formulated the Water draft proposal ‘National water extractions but limited only for projects that exceed daily extractions above 500,000 m water extractions but limited only for projects that exceed daily extractions above Central Environmental Authority related to the operation and maintenance of such projects, etc. National Water Supply National and Water Drainage Board objectives of: Water Resources Board Resources Water follows: 5.1 Available Policy Framework and the Institutional Arrangement and the Institutional Framework Policy Available 5.1 As mentioned, at present Resources the Water Board (WRB), Supply National Water and Drainage Board (NWS&DB) and the Agriculture Development Authoritygroundwater (ADA)resources arein Sri all Lanka. engagedOf these inin thethe investigations WRBwater and sectorthe todayNWD&DB into compared are and to playing thedevelopment ADA.a directly Further,muchinvolved, is moretherelated of to Centralactivewater conservation Environmentalin role the country Authority,as it (CEA)has the thoughmandate environment, to notprevent includingthe pollution waterof the environment. The main functions of these water-related institutions could be listed as water resources of the country in realizing their ultimate sustainability in realizing their ultimate of the country water resources

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 . Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Even when a considerable body of for control or regulation of the resource. institutional authority information on seasonal behavior and quality is available, there is no Responsibility for investigation into and development and regulation of groundwater is not formally assigned to any agency. The important technical inputs and policy issues that need to be addressed to improve management of water Ownership, and therefore management responsibility, of the groundwater is not clearly defined in legislation. clearly defined of the groundwater is not management responsibility, Ownership, and therefore water problems. resources; and The water development and management practices in the past, and their adverse impacts; The water development and management mitigation of the adverse impacts; The tools and policies available for the There is neither a coordinated groundwater information program nor a proper groundwater planning system. nor a proper groundwater planning groundwater information program There is neither a coordinated for groundwater allocation. There is no legal basis There is no public information or awareness program regarding groundwater or awareness program regarding There is no public information To develop guidelines and strategies for improved policies for sustainable water resources management. develop guidelines and To

ii. Crevice groundwater should not be recommended for large-scale abstractions. Crevice groundwater should not be recommended for large-scale ii. Need to raise awareness among the public on water related issues. iii. is necessary. Proper ground and surface water monitoring iv. Dialogue on the proposed water policy should be started immediately. v. iii. iv. i. ii. iii. iv. v. vi. i. ii. i. policy Available is adequate, but proper implementation is necessary to overcome the present ground and surface The meeting was well attended, with over meeting 30 many participantssuggestions were put forward fromfor achieving variousthe ultimate objectivewater-related of sustainable water agencies.management in the Atcountry. Based theon the end discussions of held theduring the meeting, a list of recommendations was formulated. The main 5.4 Policy Gaps Identified during this Study 5.4 Policy Gaps Identified In this study, several issues were identified as urgent challenges to be immediately addressed. Among those, the most important issue is the establishment of a single authoritythe groundwaterresponsible resource. In for the overseeingpresent set managementup, as ofthere theare severalwater agencieseven and involved thoughin groundwaterthe development;WRB is responsible for managing should manage thethe groundwater resources, overallpolicies are been implemented waterpoorly with nobody taking resources,responsibility for due to confusion managing in the decidinggroundwater resources. Often who this can be one of the main reasons for many of the problems.present groundwater Furthermore, a lack of adequate the present groundwater management. seriously affected financial and trained human resources within these agencies has also recommendations made in this meeting can be summarized as: recommendations made in this meeting 5.3 Stakeholders’ Meeting 5.3 Stakeholders’ During this study a stakeholders’ meeting on “Sustainable and identify the following: in February 2007 to discuss Resources” was organized Water Management Policy: Ground and Surface Water government changed again in 2004. Secretariat Secretariat (WRS), which is a new institution set up especially for this purpose. The prime objective of this policy was to strengthen the capacity of the Sri Lankan Government and to transparent managemanner. In these water new proposals, resourcessome major deficiencies in in a the sustainable, present water, as well participatoryas groundwater management setup, were identified. The major problems in groundwater management identified in this water policy can 2000): Policy – Draft, Water (National be listed as However, with the change of government in 2001, the proposed water and, in policy2002, a major had revision was tomade to the go policy formulated throughin 2000. This policy significantis still in the changesdraft stages, as the

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 133 resource. groundwater .

Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in management/governance due to multiplicity of institutions

Groundwater Top priority for domestic purposes with an upper per capita limit Top Limitations in the existing groundwater resources Current Groundwater ownership is with the individuals, but changing ownership is a critical and sensitive issue. This was one of the main reasons for the failure of the proposed water policy Poor It is vital to limit the hard-rock groundwater resource to be used in limited applications and should base extraction investigations limits through proper scientific Complexities such as these have resulted in nobody taking the responsibility of managing the Complexities such as these have resulted in nobody taking the responsibility of WRB Act – WRB empowered the WRB by law to control, regulate and develop, including the conservation and utilization of water resources of Sri Lanka (not practiced however, asother hand the Act availableNWS&DB has given a mandate legalto the NWS&DB for provisionsthe development of water supply are schemes. confusing) but, on the

i. iii. i. ii.

b. Recommendations Identify and demarcate groundwater sensitive areas in each administrative division Regulation only in sensitive areas with the following proposed priority scheme Proper Management of the groundwater resource Management of the groundwater (1) Proper a. Main issues Based on the findings of this study, the following list of policy recommendationsissues related to the water resources of Colombo and Kandy study areas: can be suggested to overcome the 5.5 Policy Recommendations agencies and other end-users. Further, at present, information about groundwater resourcescoordinated groundwater information in program, although this some studies countryhave been undertaken is in the not past. This readilydata has accessible. not There been consolidated and, iseven in its no scattered form, it is not used to any significant extent in management decisions. Therefore, through publications that may periodically be issued, the presently aquifers availableand the informationmanagement issues need onto be the taken to differentthe general user and managers at the district level in a readily understandable manner. The information should be easy to understand to increase awareness and to obtain support managing in the Also, resources. guidelines for the safe and sustainable use of groundwater should also be framed for all types of aquifers in this The country. guidelines should be widely disseminated to both the local and district provincial Incidents of this nature, together that withgroundwater the developmentother in groundwaterurban areas hasproblems development nowof the country’s groundwater reachedresources experiencedwithout a supporting a research stageeffort to diagnose inand where troubleshoot theit isrecent useless both past,to existing and speak emerging suggestproblems, ofand without sustainableproperly managing and guiding the ongoing groundwater activities in the Therefore, country. another prime need at the present stage is the establishment of an appropriate research plan to promote both short- and long-term research and investigation programs. Funding for this may come by establishing a fund through levying a groundwater charge for heavy use. Further, monitoring as either the there changes in are the quality no or presentquantity of programsgroundwater, the actual state availableof groundwater for in the country is very uncertain. Therefore, in the absence of these information and sources,using it establishingas a a comprehensive proper and monitoringreliable information network system is essential. Without this resources initiative,of a country the are often poorly groundwater understood and over-exploited by both the decision-makers and the users of the groundwater. NWS&DB is already in the process of replacing the problem-prone groundwater scheme with surface water schemes. groundwater scheme with surface in the process of replacing the problem-prone NWS&DB is already As described in a previous section, data from the construction stage of deep groundwater wells in the Kandy study area (as Kandy in schemes supply water many Further, yields. reasonable have aquifers crevice rock hard few only that shows well as in Colombo) that were based on successful boreholes drilled in the hard bedrock have run into several problems due to a lowering of both the water levels and the yields. Hence, past experiences in Kandy and Colombo clearly show only suitable be may hence and limited very is aquifer rock hard of type this in available of groundwater amount the that for rural, small-scale water supply projects and not for large, urban water supply The soon. very available made be should and regard this schemes.in guidelines policy proper formulate to Authorities Therefore the for time it is the correct

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 WRB . . Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in

NWS&DB – Not clearly state their rights but use water for water supply schemes without the permission from NWS&DB – Not clearly state their rights important river basins, including the Mahaweli River important river basins, including the Mahaweli for hydropower generation. These types of priority listings have led to many confusions and conflicts in the past over who has the priority/right over whom to use water (e.g. Salinity intrusion into the Colombo water treatment generation) facility as water in the Kelani River is regulated at upstream reservoirs for hydropower Regulate other uses with a pre-determined priority basis (case by case) priority uses with a pre-determined Regulate other on heavy uses identify/keep records necessary but areas – no regulation Non-sensitive iv. Ceylon Electricity Board – Permission iv. is granted (and high priority given) by an Act of Parliament to use water iii. Mahaweli iii. and Irrigation Departments – Play both the roles of the regulator and user for irrigation in some ii. ii. iii. i. of all water resources of Sri Lanka WRB - Has the right to Control Regulation and Development far: a. Main Issues At present, almost all surface water sources resourcesin urbanin urban areasareas areare oftenhighly contaminatedpolluted. with coliformFurther, and shortcomingsthe nutrients. in shallowthe One present majorgroundwater management reasonstructure. As for explained these earlier, failuresthe Central is Environmental Authority (CEA)was established for the protection of any portion of the environment against waste discharges, but provisions from alsoAct its for prevention the of the WRB pollution of has rivers, streams and other watercourses. Even though there are two agencies available to prevent water pollution, due to the following reasons, prevention has not being effective so (5) Pollution Prevention Establish a clear priority policy for water allocation sectors Establish a proper mechanism to manage water use between different A proper compensation scheme for the lost opportunity (e.g., if irrigation water rights are for farmers, etc.) proper compensation lost drinking water supply, due to water taken for b. Recommendations a. Main Issues According the present policy set up: Conflicting in Water Allocation Rights Water (4) Conflicting in Demand-driven research, assessmentreconnaissance basis andand more intensively, monitoringin priority aquifers and in programsareas of declared watersensitive to groundwater. needmanagement and toareas be undertaken both on a widespread, collect these scattered data, to manage them and to make them readily accessible for all. collect these scattered data, to manage b. Recommendations with data readily available to any interested party Establish a centralized information system a. Main Issues Although some groundwater studies have been undertaken in the past, even this data is collect organizations different and scatteredkeep data essentially only for their own or use. Hence, a proper database misplaced.is necessary to Also, Need for a Well-coordinated and Reliable Information System Well-coordinated a (3) Need for in aquifers, making it a major setback in managing the resource (e.g., groundwater problems in Kandy). (e.g., groundwater problems in Kandy). it a major setback in managing the resource in aquifers, making b. Recommendations a. Main Issues sustainable exploitation and use of groundwater for all types of aquifers. and use of groundwater for all types sustainable exploitation Programs Monitoring and Investigation Regular (2) Need for Encourage surface water use and rain water harvesting, especially in sensitive areas. especially in and rain water harvesting, surface water use Encourage Establish principals for groundwater management by issuing proper guidelines for proper constriction, the safe and Limit hard rock groundwater use only to small scale/individual water supply water use only to small scale/individual rock groundwater Limit hard Establish a system for collecting groundwater-related data collecting groundwater-related Establish a system for Act of Parliament) task (already empowered by an WRB responsible for this Make At present there are no reliable, continuous or ongoing monitoring causes for difficult to determine groundwater failures in the study identify groundwater behavior trends areas and also to data available on groundwater. This has made it

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CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 135 cient surface/rain water. cient surface/rain water. 6. Acknowledgments 6. Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in education and other means of encouraging water users to use surface water during periods when there is defi available and to save groundwater for use or rainwater harvesting when it is Reduction of non-revenue water, which are very high in both study areas: 40% in Colombo and 36% in Kandy. which are very high in both study areas: Reduction of non-revenue water, in decision making raising and stakeholder (especially public) participation Awareness consultation with the stakeholders. It is therefore necessary to have strong participation from the community and licensing program to track groundwater development. licensing program to track groundwater to facilitate the planning and management of groundwater resources. water users, and to promote awareness In most cases, the exploitation of shallow groundwater is through While each small-scaleof these wells use only domestica small amount andof water, their cumulative agriculturalimpact can be As considerable. wells.it is considered impractical to regulate these small wells through water entitlements, steps must be taken to somehow users of shallow wells. of shallow aquifers and thus to safeguard the water supplies of existing control the over-use supply or sources. Proper definition for safe drinking water and a proper monitoring mechanism is necessary, as at present there is no clear definition for safe drinking water in Sri Lanka no and, proper further, guidelines for maintenance of such iv. iv. An integrated approach should be taken in the management of surface and groundwater. This may involve ii. iii. v. v. Initially, a registration program should be started for heavy groundwater users. Thereafter, establish a well- i. to punish polluters stringent legal instruments lack of ii. nutrients, etc., discharges standards for coliform, lack of (WRB) contamination especially for GW implement the laws failure to iii. (local government) from local politicians influence iv. v. the two organizations between no coordination vi. One main reason for the failure of the proposed water policy in Sri Lanka in 2000 was the poorvii. level of i.

Other Issues and Recommendations 6) Other The authors wish to thank the Freshwater Project of the Institute for Global Environmental Strategies (IGES) Japan for National The Lanka: Sri in agencies following the thank to wish also and study this for assistance financial the providing Supply Water and Drainage Board Kandy and Colombo, The Resources Water Board and the Ministry of Agricultural Agrarian Services for their support, especially in data collection Development & recommendations for sustainable water resources both in Colombo and Kandy: sustainable water resources both in Colombo recommendations for ( b. Recommendations provisions the present law with enhanced legal Strict enforcement of standards covering all pollutants discharge Introduction of new In addition to the above five main recommendations, this study identifies the following, also, as important

CHAPTER 3 CHAPTER CHAPTER 2 CHAPTER CHAPTER 1 CHAPTER CHAPTER 1 CHAPTER 2 CHAPTER 3 http://earthtrends. Government of Sri proceedings of the 20th WEDC Conference on Report, Water Resources Board 2A, Gregory’s Avenue, Agro-Well and Pump Diffusion in the Dry Zone of Agro-Well Sri Lanka: Water Resources Council Water and Secretariat, wssinfo.org Drinking Water. Coverage Estimates of Improved Post-Tsunami Recovery Program. Preliminary Damage Recovery Preliminary and Program. Needs Post-Tsunami Heavy Metal Levels in Groundwater in the Ratmalana-Moratuwa Industrial Industrial Ratmalana-Moratuwa the in Groundwater in Levels Metal Heavy Final Report on the Rapid Environmental Assessment on Post-Tsunami Brown http://www.iwmi.org Groundwater Depletion due to Agro-Wells, Tsunami Impact Tsunami on Shallow Groundwater and Associated Supply Water on the East Coast of Sri Research Sessions, Department of Civil Engineering, University of Moratuwa, Sri Lanka. of Civil Engineering, University of Moratuwa, Research Sessions, Department Groundwater Resources of Sri Lanka. http://www.statistics.gov.lk Sustainable Groundwater Management in Asian Cities Sustainable Groundwater Management in Jan. 10-28, 2005. http://www.adb.org/Tsunami/sri-lankaassessment.asp Jan. 10-28, http://www.centralbanklanka.org/ Department of Civil Engineering, University of Moratuwa, Sri Lanka, pp 47-51. University of Moratuwa, Sri Lanka, pp Department of Civil Engineering, Water Resources Water and Freshwater Ecosystems Country Profile Sri Lanka, Resource Water Institute web page: UNEP, 2005. After the Tsunami - Rapid Environmental Assessment Rapid Environmental - Tsunami After the 2005. UNEP, http://www.unep.org/tsunami/tsunami_rpt.asp Kandy District Supply Water Development Program, National Supply Water and Drainage Board, Main Report Sector Planning Section, September, Villholth K G, Amerasinghe P H, Jeyakumar P, Panabokke C R, Woolley O, Weerasinghe M D, Amalraj N, Prathepaan S, Bürgi N, Sarath Lionelrathne Lionelrathne Sarath N, Bürgi S, Prathepaan N, Amalraj D, M Weerasinghe O, Woolley R, C Panabokke P, Jeyakumar H, P Amerasinghe G, K Villholth D M D, Indrajith N G, and Pathirana S R K, 2005, Lanka: A post-tsunami well support recovery initiative and an assessment of salinity of groundwater in areas Batticaloa three and in Management Institute Eastern Sri Lanka International Water WHO/UNISEF Joint Monitoring Program for water supply and sanitation (July 2004); Lanka Sri Lanka Department of Census and Statistics. Panabokke, C.R. and Perera, A.P.G.R.L., 2005. Lanka Kikuchi, M.; Weligamage, P.; Barker, R.; Samad, Barker, M.; Kono, H.; Somaratne, H.M. 2003. P.; Kikuchi, Weligamage, M.; K.L.L. Premanath and Tissa Liyanapatabendi (1994). 2002 Management Institute. Water Research Report 66. Colombo, Sri Lanka: International Prospects. Status and Future Present Past Trends, Danish Hydraulic Institue (1999). Kelani Ganga basin detailed basin assessment, working document C. (1999). Kelani Ganga basin detailed basin assessment, Danish Hydraulic Institue “Earthtrends” 2003, ADB, Japan Bank for International Cooperation and WB, 2005. Sri Lanka – 2005, Colombo, Sri Lanka. Assessment. of Sri Lanka ; Central Bank References Main Report Sector Planning Section, 1991 Supply and Drainage Board, Water Development Program, National Supply Water Colombo District Gunawardhana W D D H, Jayaweera M W and Kasturiarachchi J C, 2002, 2002, C, J Kasturiarachchi and W M Jayaweera H, D D W Gunawardhana wri.org/text/water-resources/country-profile-167.html out in 2002, survey carried comprehensive A Area: Jayaweera Mahesh, Ajith de Alwis and Suren Wijeyekoon, 2005; in Sri Lanka, Environment National Water Resources National Water Policy and Arrangements Institutional 2000, Draft Proposal, affordable water supply and sanitation, Colombo, Sri Lanka, pp. 11-13 water supply and sanitation, Colombo, Sri Lanka, affordable Sri Lanka 2004 Statistical and Data Year 2006, Sheet Publications Division, Department of Census and Statistics, Ministry of Interior Colombo – Sri Ratnayake U R and Herath G B B, Sri Lanka Wattala, 2005. Development Report – for UN-WWAP", "RecentWater on Sri Lanka National Workshop Proceedings, "Prearatory Changes in Water Cycle and its Effect on Natural disasters and Eco Systems of Sri Lanka", Colombo-7 Sri Lanka January, 2005 Colombo-7 Sri Lanka January,

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