Ana Gunatilaka

Geological Consultant, National Science Foundation of Sri Lanka


             The 2004 December megatsunami that originated in the Sunda Trench region is probably the greatest ever in modern human history. In Sri Lanka, the loss of life is now well over 35,000 and the cost of material damage to inhabitants of the coastal zone has still not been assessed, but will probably exceed several billion dollars.


During the past three months, several Sri Lankan research teams have been gathering data around the coast on various aspects of this tsunami, based on the guidelines given by the Intergovernmental Oceanographic Union (IOU). Data on inundation distances, maximum run-up heights, maximum tsunami heights, standing water levels, eye-witness accounts etc. have been collected from over 200 localities and is still continuing. The initial inundation mapping surveys indicate quite dramatically that the above tsunami parameters are highly variable even within very short distances (<100 m), indicating that several variable factors have contributed to the inundation pattern at a given locality. The presence or absence of mangroves, fringing coral reefs, nearshore bathymetry, angle and direction of wave approach, shape of the coastline, artificial coastal boulder barriers, coastal dune complexes, topographic profiles and gradients from coast to inland are among them. Such detail is required by the government of Sri Lanka for its relief and rehabilitation efforts, relocation programs, tsunami mitigation and management planning and to evaluate the overall impact of the tsunami on the social and economic life of all the stakeholders in the coastal zone.                                                    


Perhaps the most damaging impact of the tsunami is on the groundwater table in the coastal zone. Over 50,000 drinking water wells abandoned, sewerage systems damaged, with cross-contamination of the water table. Presently, almost a million people in the coastal areas are being supplied with drinking water on a daily basis, at tremendous cost to the state, NGOs and local authorities. Water quality was already poor even before the tsunami. Now it is critical. Further, unscientific cleaning activity by continuous pumping by individuals is only exacerbating the situation, with further salt intrusion into the wells. The groundwater problem will be the most challenging aspect to the authorities and it may take a very long time to restore normalcy. The most highly focused research efforts are on groundwater, with three teams operating in different areas of the coastal zone. Hopefully, the data gathered will lead to a permanent groundwater monitoring and Integrated Water Management Plan for the affected zone. The opportunities for research on groundwater modeling will be an added bonus. Water that was freely available by nature has now become a very precious commodity.


Two research teams are studying sediment profiles along selected traverses (initially 20 traverses are envisaged) and encompassing the wide inundation variability seen. The purpose of this study is to correlate the sediment sequences and their depositional features with the combined flow characteristics of a tsunami wave as it moves inland and withdraws – data that will be useful in studying paleo- megatsunamis. Initial coastal modeling studies indicate that a bay and headland or promontory is the most devastating geomorphic combination during a tsunami. The bay creating a funnel-like effect and the headland a wrap-around effect for the tsunami wave, as happened in the port city of Galle. The location of the greatest ever train disaster in history (almost 1500 casualties), occurred in a straight stretch of coastline with a well developed fringing reef. Generally, the coral reef had hardly any major effect as a protective barrier against the waves and may even have aided the wave train to gain height. More important was the landward topographic gradient from the coastal highway to the rail track (~ 300m away), an elevation difference of about 1 m, when the 8-9m high second wave generated sufficient momentum and energy to topple over the crowded train and the heavy engine power unit, which rolled over almost 50m further. Further north, along a straight stretch, a large and extensive boulder barrier built to prevent severe coastal erosion was broken through, with boulders strewn over 50m inland and the wave inundating 800m. The high (15m) coastal dune complexes in Hamabantota and thick/wide mangrove belts were the most effective barriers, with little damage to show. 


It became quite obvious that construction quality in the coastal zone is much to be desired. Foundations were not deep or reinforced and were on loose sand. Houses toppled as the debris-charged wave created a path of destruction inland. There are some indications that the geotechnical properties of the soils in the coastal zones may have been altered. This is also being investigated. Obviously, a new building code needs to be strictly enforced. Much of this research initiative has been generously funded by the National Science Foundation of Sri Lanka.


Generally, the east coast of Sri Lanka was the worst affected as it faced the maximum and direct impact of the waves. Even in areas where the run-up heights were around 4-5m (as in Trincomalee), the damage was high. These initial investigations have given a good insight as to the behavior of tsunami waves. Hazardous and safe coastal areas have been recognized and the people made aware. The government has now enforced a coastal restriction or buffer zone, (of 100 and 200 m width for the west and east coasts), where no new construction activity will be permitted barring a few exceptions. Surveys indicate that ~65 per cent of the coastal inhabitants would opt for alternate land inland. This is another big task for the government. The required land may not be available. Also, people may not want to go too far from their ancestral villages, which gives them social cohesion and psychological sustenance. The government is bound to be flexible in this matter, yet enforcing strict guidelines for future activity. Another major quake may not necessarily generate another megatsunami (as was proven on March 28th 2005). However, disaster mitigation and management planning, early warnings, education and awareness programs will be all the more important in the future. The tsunami was a wake up call. Disaster awareness has become a new element in Sri Lanka. Efficient and reliable communications will be the key to mitigation efforts.                                                                                                                                                                                                                         

Ana Gunatilaka Ph.D.                                                                                                  

National Science Foundation,

47/5, Maitland Place,

Colombo 7

Sri Lanka.




Groundwater Conditions in the Coastal Region of Sri Lanka


A.P.G.R.L. Perera, Hydrogeologist,

Water Resources Board, 2 A, Gregory’s Avenue, Colombo -07


Seven main types of groundwater aquifers have been identified and characterized in Sri Lanka. Of these, five aquifers are associated with the coastal region of Sri Lanka. These are as follows.


1.    Shallow Karst Limestone Aquifer of Jaffna Peninsula

2.    Deep Confined Aquifer

3.    Coastal Sand Aquifer

4.    Alluvial Aquifer

5.    South Western Lateritic Aquifer


The shallow karstic aquifers are mainly confined to Jaffna peninsula and occur in the channels and cavities of Miocene Limestone. The shallow groundwater forms mounds or lenses overlying saline water and is used most intensively for agriculture and domestic purposes.


Deep confined aquifers are found in the coastal regions of the north and northwest extending from Puttalam to Jaffna and towards Mulativu. Eight distinct deep aquifer basins have been identified in these coastal regions. The average depth of wells reaching the artesian aquifer in these basins is from 60 to 80 m and the yield of these wells is around 300 – 1500 lpm. Groundwater in Vanathavilluwa basin is used more intensively for irrigated agriculture of high value crops. Palavi and Madurankuliya basins are intensively used for Prawn Culture farming. Electrical Conductivity values of groundwater in this region are moderate to high.


Coastal sand aquifers -3 types have been recognized and characterized; (a). shallow aquifers on coastal spits and bars in the northwest are found in Kalpitiya peninsula and Mannar Island. (b).shallow aquifers on raised beaches and low sand dunes in the South and East are predominantly found in Nilaveli, Pulmoddai, Kalkudah and Koggala. Generally they are distributed all round the island. (c). moderately deep shallow aquifers in inland beach plains in the west are found in Katunayake and Chilaw.


Groundwater in these aquifers gets collected in the forms of fresh water ‘lenses’ above denser saline water. Coastal sand aquifer regions of Sri Lanka are densely populated and intensively cultivated. Groundwater usage is largely uncontrolled in these regions and excessive in some places, causing brackish water intrusions. Previous studies show that significant contamination of the aquifer has taken place with nitrates due to extensive use of agrochemicals and fertilizers in Jaffna and Kalpitiya peninsulas. Electrical conductivity of groundwater in these regions is good to moderate.


One of the largest carriers of groundwater is river alluvium. The flood plains of Rivers such as Kelani Ganga and Deduru-oya have broad and deep alluvial beds in their lower reaches in the coastal region to West.


Laterite aquifers are found in the coastal region of southwest Sri Lanka extending from Kalutara to Matara. Wherever laterite outcrops, a large number of wells are developed on it. Owing to the variable thickness of the laterite, wells are generally deep, often going down to between 15 and 30 meters below surface level.


The remaining hard rock regions of Sri Lanka encompass about 80% of the Island. Groundwater is found in the fractured and weathered zone. A weathered rock zone is identified as a regolith aquifer. Only few areas of this hard rock region are exposed in the coastal boundary.

More than 90% of the total requirement of water in cities such as Puttalam, Mannar Jaffna and Batticaloa in the coastal region is used groundwater. Biological contamination of groundwater is a common problem in all the coastal regions.





H.A.Dharmagunawardhane , Department of Geology, University of Peradeniya,

 Sri Lanka


Occurrence and distribution of ground water in the coastal areas of Sri Lanka mainly depend on geology, geomorphology and litho-stratigraphy of the areas concerned. Sri Lankan coast line which extends over a 1700km long and generally low-lying stretch and shows considerable diversity in geology and landforms. Geologically, about 90percent of the country’s landmass is underlain by Precambrian basement rocks and the remaining area (10percent) by sedimentary rocks (limestone and sandstone) of Miocene age. The sedimentary rocks are found in the northern and north eastern part of the country as a 20 to 40Km wide belt  extending from  south of Puttalam  through Jafna peninsula to Mullativu. The above two main geological units along the coast have been modified by the Pleistocene and Holocene sea level fluctuations and climatic changes causing deposition of  sand, clay, gravel and peat deposits along low-lying coastal areas. These geological proceses resulted in the formation of a multitude of complex and discontinuous aquifers along the coastal areas as observed today .


Although there are complex geological and hydrogeological conditions, prevailing locally,  the coastal  belt can broadly be divided into three aquifer regimes,


a)      Northern and north western limestone aquifers

b)      Quaternary unconsolidated sandy aquifers

c)      Combined rigolith and fissured crystalline aquifers


Northern and north western limestone aquifers


Highly Karstic and permeable  Miocene limestone aquifers are present along the Northern and North western coastal belt from Puttalam through Jaffna peninsula to Mullativu. In this belt from Mannar to Jaffna  the limestone aquifer is overlain at many places by permeable and comparatively thin  Quaternary (and recent) sand and silty clay  deposits. The aquifer  possesses mostly unconfined conditions with a ground water level at a depth of between 5 to 15m from surface. The transmissivity of the aquifer varies between 500 to 2000m2/day and the productive aquifer extends down to more than 100m below the surface.  Towards Mullativu in the north east, the limestone is confined between upper quaterny deposits and lower sandstone bed with a sedimentary sequence exceeding 300m in thickness. These conditions have created a multi aquifer system consisting of shallow unconfined and deep confined aquifers. In the North western coastal belt extending from Puttalam to Mannar, the limestone aquifer is overlain by a 60 to 100m thick Quaternary sand and clay sequence  The lime stone aquifer is dissected and vertically displaced by asystem of faults creating confined aquifer conditions at many locations.  The transmissivity of the aquifer ranges between 500 to 1200m2/day with a thickness ranging between 100 to 200m. Artesian flowing wells can be seen at several places in this area close to the coast.


High nitrate in groundwater in unconfined aquifer areas arising from intense agricultural practices and  High chloride  associated with saline water intrusion due to uncontrolled  groundwater abstraction  are  common water quality problems in the sedimentary aquifer system.


Quaternary unconsolidated sandy aquifers


Wind blown accumulations of recent sands forming dunes occur along almost one fifth of the coast line of Sri Lanka These together with Pleistocene and Holocene deposits of sand  has created sufficiently thick (up to 25m)  local and discontinuous highly productive aquifers  in certain areas. This type of aquifers are found along most parts of the eastern coast from Hambanthota to Mullathivu and in the western coast from Negombo to Palavi.  The transmissivites of these aquifers are in the order of 2500m2/day.Good quality groundwater occurs in these aquifers and the groundwater table is present at a depth between 2 to 6m from the surface.  In these aquifers, fresh water floats on the saline water at fresh water saline water interface on the seaward side of the aquifers. Excessive pumping often causes saline water intrusion. These unconfined (and occasionally semiconfined) aquifers are highly vulnerable to contamination where direct infiltration of contaminants is common from agricultural activities and onsite waste disposal in these areas.


Combined residual/rigolith and  fissured crystalline aquifers


The slightly elevated coastal area from Mount Lavinia in the west to Hambanthota, in the south is dominantly underlayn by laterite and  residual weathering products of crystalline rocks. This 2 to 20m thick weathered overburden is underlain by crystalline basement rocks which are also exposed at the surface at some locations. Narrow discontinuous sand dunes and some alluvial deposits are also present at some low lying locations along this coastal belt. Marshes and wetlands are a common feature in the western and south western parts, specially in association with estuaries  Groundwater found in the weathered zone (rigolith) is heavily used in this area mainly through traditional dug wells. Water level is found at depths between 2 to 6m from the surface  The transmissivity of the regolith aquifer is generally low and varies between 2 to 80m2/day. The Most productive part of the aquifer is the moderately weathered transition zone or the lower part of the regolith which is more sandy than clayey.  Water quality is generally good and is slightly acidic specially when found in laterite.  The underlying hard rocks form less productive discontinuous and local aquifers only where fissures are developed due to fracturing and weathering. Often the fissured/fractured rock is hydraulically connected with the overburden. Thus it can receive recharge from the water bearing overburden. Fracture zones in the rock  extend down to more than100m but majority of the productive ones are situated at depths less than 45m. Groundwater in the hard rock aquifer is mainly extracted by water supply bore holes. Substantial yields have been encountered where such boreholes are located on regional fracture zones.


Alluvial formations that occur in the low lying marshy lands, wetlands and estuaries have very shallow groundwater levels but often contain brackish water unsuitable for drinking and domestic purposes.


As indicated above, the coastal aquifers in Sri Lanka are diversified in character and show variable hydrgeological and hydrochemical properties. These variable characters should be taken in to consideration in their development, rehabilitation, conservation  or management.




Pre and Post Tsunami Effects on Agricultural Lands of Sri Lanka


Ranjith. B. Mapa,

Faculty of Agriculture, University of Peradeniya


W.M.A.D.B. Wickramasinghe, D.N. Sirisena

Rice Research and Development Center, Bathalagoda


K.M.A. Kendaragama

Natural Resource Management Center, Department of Agriculture, Peradeniya




Due to the Tsunami disaster, which took place on 26th December 2004, lands along about 1200 km of the costal belt of Sri Lanka were damaged. In some places sea waves came into about 3 to 5 km from the coast damaging the crops grown in these areas.  With the action of sea waves, the lands were physically damaged by removal of soil by erosion and deposition of large amounts of sand and other debris. As sea water contains considerable quantities of sodium bearing salts, its intrusion creates soil salinity and dispersion of soil particles destroying the soil structure. According to estimates by FAO, about 4500 ha of agricultural lands were damaged along the coastal belt of Sri Lanka. Therefore, there is a need of rehabilitating the agricultural lands affected by the Tsunami disaster.  The objective of this paper is to assess the damages to agricultural lands from salinity due to Tsunami in selected locations in Sri Lanka and to propose methodology to reclaim them.


For this study, Amapara district in the East of Sri Lanka which was extensively damaged by the Tsunami was selected. This area is called the rice bowl of the country giving high yields amounting to 6 tons per ha. Electrical conductivity, which is an indicator of soil salinity, was measured in effected lowland rice fields as well as in cultivated highlands. Salinity of adjacent unaffected areas were measured and taken as pre-Tsunami values.  Nindavur area was selected to assess the damage to rice fields while Vinaygapurum in Thrukkovil where tomato, chillies, cowpea and eggplants were grown extensively was selected to assess the damage to the highlands.  Electrical conductivity (EC) was measured in the saturated soil paste from 0-5, 5-15 and 15-30 cm depths at 200, 400 and 900 meters from the sea after 18 days of the disaster.  This was followed by measurements after 4.5 months and 8 months at the same sites in the rice fields in Nindavur.


The measurements after 18 days of Tsunami showed that the EC values of the saturated paste of the effected areas were highest in the rice fields nearest to sea (200 m), showing 6.12 and 2.94 dS/m respectively at surface and subsurface depths. At a distance of 900m the EC values decreased to 0.85 and 1.28 dS/m in surface and subsurface respectively. The standing water in some depressions in the rice fields showed an EC value high as 11.46 and 5.84 dS/m at 200 and 400 m away from the sea.  In the unaffected rice lands the EC was low as 0.07 dS/m.


The next crop of rice was sawn after 4 months of Tsunami.  In the same area where the sea water was stagnant EC values decreased only to 3.2 dS/m and the seed germination was very low resulting in a poor stand of crop. Even if rice varieties resistant to salinity can tolerate EC values higher than 4 dS/m the variety grown (BG 94-2) can withstand only lower salinity levels. Due to ploughing at the same depth repeatedly and puddling, a hard pan is formed in lowland rice fields around 15 to 20 cm depth, which restrict deep percolation. In fields where surface drainage was satisfactory, most of the salts got washed way reclaiming the land naturally. The EC values of these lands decreased to 1.7 dS/m after 4 months of Tsunami and a satisfactory stand of crop was observed. The rice crop is irrigated from Senanayaka tank and the irrigation water showed an EC value of 0.18 dS/m. The drainage facilities of some rice fields were improved with the assistance provided by a private company and the drainage water showed an EC value of 2.84 dS/m. At the same time well water in the same area showed a higher EC value of 3.63 dS/m.


At the harvesting time of the crop (8 months after Tsunami) the EC values of the same field with stagnant water showed an EC of 1.06 dS/m in surface soil which increased to 1.85 dS/m at 15/30 cm depth.  This indicates that salinity increased with depth due to leaching but stopped at the hard pan.  In this land, a thin hard crust was formed upon drying during harvest time indicating soil dispersion due to higher Na content.  Where surface drainage was satisfactory the EC values were low as 0.02 dS/m in the surface and to 0.03 dS/m in the subsurface.  In the unaffected areas (control) EC values were low as 0.03 and 0.04 dS/m respectively in surface and subsurface soils.


In the highlands the highest EC value measured after 18 days of Tsunami was 0.60 dS/m in the sub soil at 400 m away from sea. Even in the highlands, where water logged conditions prevailed the EC was higher as 3.5 dS/m and the well water showed an EC values of 3.14 dS/m. The highlands are well drained and therefore salinity is easily leached to deeper layers. 


These data clearly demonstrate that in certain pockets of land, especially in rice fields where the drainage is poor, the salinity still prevails at high levels affecting the rice crop, even after 8 months of Tsunami. There is a need to identify the land areas where salinity still remains at high levels and improve surface drainage for the farmers to cultivate them even in future seasons. In this exercise priority should be given to lowland rice lands than for highlands. 



Synopsis of Post-Tsunami Rapid Environmental Assessments in Sri Lanka


Ministry of Environment and Natural Resources


13th June 2005



1.         Scope of the assessments


In an immediate response to the tsunami, the Minister of Environment and Natural Resources, Hon. A. H. M. Fowzie, took steps to carry out a Rapid Environmental Assessment (REA) of the tsunami-affected areas, in close cooperation with the Central Environmental Authority (CEA), and with the assistance and support of the United Nations Environment Programme (UNEP).  The REA was undertaken by scientists from Amparai, Colombo, Eastern, Ruhuna, Jaffna, Moratuwa and Sri Jayawardenapura Universities.  It was in two parts, focussing respectively on the ‘green’ environment (ecosystems, biodiversity, protected areas and farmlands) and the ‘brown’ environment (pollution, debris and impacts on human settlements and infrastructure). 


The ‘green’ assessment involved describing, at one-km intervals over more than 800 km of affected coastline, transects perpendicular to the shore and running inland from the high tide line.  Data were collected on vulnerability, physical, ecological and social damage, land use, constraints on and options for land use, and on the precise pattern of tsunami inundation.  All observations were georeferenced digitally.  These profiles provided a significant sample of observation points and a set of locations where the complex interaction of the tsunami with topography, ecosystems and human settlements could be analysed and understood.  Each was also an observation point for overlapping descriptions of the surrounding area, yielding continuous coverage of the affected coast.


The ‘brown’ assessment concentrated on contamination at over 750 sites where particular risks were known to exist because the tsunami affected facilities for storage or processing of potentially hazardous materials.  These included both established solid waste dumps and new ones used to dispose of tsunami debris, as well as storage and processing facilities associated with the commercial, health, security, transport, tourism, agriculture, fisheries, mining and other sectors.  Each site was assessed for type, scope and intensity of pollution, looking at faecal, oil and toxic contamination, visual, air, odour and thermal pollution, disease risks and salinization.  Samples of water and soil were collected wherever necessary and analysed chemically.  Sites were scored for the severity of impact and conclusions drawn on the urgency and feasibility of mitigation in terms of either short-term, medium-term or long-term projects.


This document is a synopsis of the main findings of the ‘green’ and ‘brown’ assessments, which also takes into account findings by other national institutions (CCD, DWLC, NARA, UDA, etc.) and international agencies (IUCN, IWMI, UNEP/OCHA, ADB, JBIC, JICA, World Bank, FAO, etc.).  It reviews the main conclusions, drawing out of them a number of recommendations for action, upon which a portfolio of proposed remediation projects is based (Annex 1).  From these, detailed proposals can now be prepared to guide investments by government and potential donors.

2.         Summary of assessment findings


a)         Variation in depth of penetration.


The tsunami impacted the eastern coastline of Sri Lanka shortly after 08.00 hours and then swept along the southern and south-western shores over the following 90 minutes or so.  There were typically three large waves and several lesser ones at each site, with the largest ranging from 3-9 metres high at the shore, and penetrating inland for distances ranging from a few tens of metres to up to 3 km.  The median depth of penetration was about 300 m in Trincomalee and Ampara districts, 130 m in Batticaloa, 110 m in Matara, 100 m in Hambantota, 70 m in Galle, and 50 m in Jaffna district.  The depth of penetration was influenced by the shape of the sea-bed, which is thought to have funnelled the wave into a higher shape in some areas, and by on-shore terrain and vegetation, being resisted by large sand dunes, absorbed by mangroves and lagoons, and facilitated by inlets and estuaries. Complex coastal environments (e.g. those containing beaches, dunes, lagoons, plantations, mangroves, rivers, home gardens, etc. in the same area) absorbed tsunami energy and provided protection.


b)         Debris and solid waste.


Well over 500 million kg of rubble were created by the tsunami and are still posing an enormous challenge to the solid waste management system.  Debris and marine sand, whether deposited by the tsunami or by subsequent clean-up operations, block drainage channels in many areas, posing an acute risk of water-logging and loss of agricultural land, as well as increased mosquito-borne disease.


c)         Salinization of drinking water wells.


This has affected large areas and rendered more than 15,000 wells unusable, greatly reducing water supplies.  Over-pumping of wells in an attempt to clean contaminated or saline water and restore fresh-water supplies has often encouraged salt-intrusion, which has done more harm than good.  Existing mobile water treatment units in this respect need scrutiny.


d)         Contamination of water bodies.


Several coastal water bodies have been contaminated with salt-water, debris, floating material, faecal matter and black sediments, etc. Karagan lewaya, Hambantota, Sastarawila, Panama and Arugam Bay are some sites that need urgent restoration. In these cases, the original ecosystem is completely disrupted, much of the fauna and flora have died, and natural self-purification has ceased, resulting in highly toxic water bodies.


e)         Resettlement and reconstruction.


These activities are placing a huge burden on natural resources, especially through the location of new settlements in or near protected areas and other ecologically sensitive locations, and increased demand for sand and wood for reconstruction and firewood for brick-making. Faecal contamination of ground water has become a major issue in some of the tsunami-affected areas, and further resettlements could worsen the situation.  Without careful management, these activities have the potential to cause more irreversible damage to Sri Lanka’s environment than did the tsunami itself.


f)          Damage to marine ecosystems.


These showed a variety of impacts; shallow fringing coral reefs were damaged mechanically, with breakage of branching corals and dislodging of boulder corals, with some smothering by debris carried by backwash; intact coral reefs acted as buffers, but these were few because of pre-tsunami damage from mining, blast-fishing and bleaching.


g)         Damage to shoreline ecosystems.


Estuaries often acted as channels of entry for the tsunami, facilitating damage and salt intrusion far inland.  Front-line mangroves were badly damaged, while deeper mangroves were left intact and dense mangroves converted the wave into a flood.  Lagoons absorbed tsunami energy, but in doing so lost seasonal sand barriers, their banks were scoured, and mangroves at their entrances were dislodged, but they were otherwise little affected and/or recovered quickly (apart from litter and debris pollution, and some cases of blocked water flow causing stagnation).  Large, vegetated sand dunes stopped tsunami intrusion.  Beaches were eroded and scoured, losing width and height, mainly from tsunami back-wash.  There is much debris on most beaches, including unexploded ordnance in some areas.


h)         Damage to inland ecosystems.


There was severe damage in near-shore areas, including to seashore Pandanus and creeper vegetation, and inland palmyra trees, with near-shore coconuts less affected as were inland economic trees.  Casuarina plantations proved vulnerable to tsunami damage and by themselves had little protective value, though in places they helped stabilise sand dunes which themselves moderated the tsunami.  Alien invasive species have been spread by the tsunami into new areas.


3.         Summary of recommendations


a)         Urgent interventions in particular sectors.


·        Debris management - mobilise local government and communities to undertake immediate sorting and safe and environmentally-responsible disposal of debris on a ‘cash-for-work’ basis at the local level under the direction and guidance of the CEA.

·        Environmental contamination - manage pollution hotspots associated with solid waste dumping and sludge disposal; sample and test marine sludge deposits for possible heavy metals and other persistent pollutants, and remove and safely dispose as appropriate.

·        Rehabilitation of natural water bodies - remove debris and sludge, release stagnant, anoxic and contaminated water, and restore pre-tsunami ecological conditions to the extent possible.

·        Restoration of land drainage - clear sand and debris from drainage channels, in order to prevent the loss of productive land by water-logging, and the increased transmission of mosquito-borne diseases.

·        Sustainable recovery and reconstruction of water supplies - train all staff who manage water treatment and pumping units to maximise the sustainable rate of recovery of safe water supplies and to prevent over-pumping and irreversible salinisation of wells and ground water; invest in the provision of drinking water supply in many affected areas.

·        Sand mining and nourishment- identify areas where the landward sides of large sand dunes could be harvested for sand, or wind-blown sand trapped in commercial quantities, without affecting the dunes’ ability to protect the coast; areas that need nourishment must also be identified and sand pumping carried out as needed.

·        Ecosystem management – work with NGOs, local community and other responsible elements to rehabilitate damaged ecosystems with priority to Special Area Management (SAM) sites.


b)         Urgent interventions at specific sites.


·        Clearing debris, and in places unexploded ordnance from beaches, seashores, near-shore sea beds and coral reefs.

·        Restoring access channels for fishing boats.

·        Replacing and/or relocating safe anchorages.

·        Identifying sites for properly-regulated sand mining.

·        Identifying sites that need proper water supply and sanitation facilities.

·        Regenerating and stabilizing sand dunes and the banks of drainage channels.

·        Removing sand and debris from drainage pathways and farmland.

·        Assessing and restoring ground-water quality.

·        Identifying land suitable for resettlement, with special attention to freshwater supply, drainage, fishery livelihoods and tenure/resource conflicts.

·        Restoring original ecosystems in water bodies and SAM sites.


c)         Urgent strategic interventions.


·        Coordinating post-tsunami investment through a standing committee co-chaired by MENR, CEA and TAFREN, and expert/donor round-tables as needed, to ensure that environmental concerns are fully integrated in all decisions on national reconstruction, and to coordinate country-driven implementation of all relevant government recommendations.

·        Strengthening national policy on the management of critical environmental issues through joint MENR-CEA-TAFREN leadership, including policy on the environmentally-responsible disposal of debris and solid wastes, the extraction and sustainable supply of safe drinking water, the restoration of effective drainage to farmlands and urban areas, and the prevention of deforestation resulting from construction and resettlement.  The policy framework should be used to develop mandatory guidelines to ensure uniform practice.

·        Enhancing the role of MENR in national reconstruction planning, by resourcing it to allow the participation of its officials and/or consultants in all relevant decisions.

·        Building institutional capacity for environmental management through an appropriate combination of training, addition of expert staff, resourcing to allow the use of national consultants, provision of appropriate equipment, hardware and software, and resourcing to support field work, data and sample analysis and reporting.

·        Building capacity for public participation in ecosystem restoration by encouraging and enabling local authorities to develop and implement integrated local plans at the community, divisional and provincial levels that incorporate options for restoring ecosystems known to help protect against environmental shocks (e.g. mangroves, dunes, reefs and wetlands) as well restoring home gardens, plantations, bunds, banks, channels and other features of livelihood significance that also help protect the environments where people live.

·        Disseminating information by producing and distributing clear, simple, illustrated guidelines in appropriate languages, on how safely to classify, separate, compost, re-use, recycle and dispose of solid waste and debris, how to design and construct improved housing and sanitation using safe materials, and how to identify and correct environmental problems such as blocked land drainage, salinisation, and the spread of alien invasive species.

·        Mapping of coastal zone terrain up to the 10 m contour, to support priority setting for coastal defence investments.

·        Encouraging and enabling regional collaboration, by ensuring that Sri Lanka participates fully in regional partnerships for information sharing, technical support and capacity building.

·        Building consensus on national priorities through a national round-table discussion on lessons learned from the tsunami, and national priorities for restoration and development in the coastal zone.


4.         The path ahead


The above-mentioned body of recommendations and potential projects has emerged based on the findings of the REA.   A Development Forum held in Kandy during May also highlighted the need to address environmental concerns in the government’s Post-tsunami Recovery and Reconstruction (PTRR) strategy.  There is now an urgent need to begin aligning the recommendations of the REA with those of the Development Forum, and to engage the UN family and potential donors in their coordinated implementation in line with the PTRR process. To this end, the Development Forum recommended the following steps:

·               Establish a high-level Multi-stakeholder Platform, comprising MENR, TAFREN, CEA, UDA and other key institutions, to coordinate and direct environmental inputs to the implementation of the PTRR strategy.

·               Establish a Helpdesk in Colombo and a network of District Environmental Helpdesks, to facilitate rapid responses to problems experienced at the local level in the implementation of the environmental component of the PTRR strategy.

·               Hold meetings of national, provincial and local governmental and non-governmental institutions:

o       to develop a comprehensive plan of action for environmental remediation and integration of environmental considerations in the implementation of the national reconstruction and development programme;

o       to align environmental needs with donor assistance; and

o       to make institutional arrangements to prevent the duplication of effort, ensure coordinated environmental action at all levels, and arrange for monitoring and further support for implementation.




Annex 1: Summary of proposed urgent interventions

Project theme


Proposed intervention and location

Indicative budget (US$)

1.  Managing debris and waste

Tsunami-affected areas

Mobilise local government and communities to undertake immediate sorting and safe and environmentally-responsible disposal of debris and solid wastes on a ‘cash-for-work’ basis at the local level with the direction and guidance of CEA.



2.  Assessing and remediating environmental contamination

Component 1: Tsunami-affected water bodies in Sri Lanka

Component 1:  Restore affected lagoons and estuaries (e.g. Karagan lewaya, Hambantota, Sastarawila, Panama, Arugam Bay). Sample and test marine sludge introduced to water bodies by the tsunami for heavy metals and other persistent pollutants; remove and dispose of safely as appropriate.




Component 2: Abandoned and active mineral pits.

Component 2: Remedy pollution hotspots associated with solid waste dumping and sludge disposal (e.g. at Thelwatta, Akurala, Habaraduwa and Ambalangoda).




Component 3: Tsunami-affected areas in Indian Ocean

Component 3: Share information among countries concerning the sampling and testing of marine sludge for persistent pollutants, and its removal and safe disposal.




Component 4: Tsunami-affected fishery harbours

Component 4: Clean, rehabilitate, restore or reconstruct fishery harbours as needed (e.g. Panadura, Beruwela, Hikkaduwa, Tangalle, Hambantota, Kirinda harbours and Arugam Bay, Kalladi Beach, Vallachchanai lagoon anchorages); correct sanitation and waste management issues.




3.  Rehabilitating ecosystems

Component 1: Rehabilitation of SAM sites

Component 1: Rehabilitate SAM sites with removal of debris and sludge, dilution of stagnant, anoxic and contaminated water, and restoration of pre-tsunami ecological conditions.




Component 2: Rehabilitation of Protected Areas

Component 2: Restore natural vegetation and eliminate alien species, restore damaged sand dunes, clear debris (e.g. Yala, Bundala).




Component 3: Rehabilitation of wetlands

Component 3: Restore mangroves in the first 300 metres on both sides of the Odu lagoon, and on both sides of the Batticaloa-Vaharai road, where previously cleared for security reasons.



4.  Restoring land drainage

Tsunami-affected areas

Clear sand and debris from drainage channels to prevent water-logging and impacts on farming and public health. Make new drainage as appropriate so as to minimize the water –logging capacities



5.  Water supply and sanitation

Component 1: Tsunami-affected areas

Component 1: Provision of water supply.  Reconstruct new water supply schemes and sanitation facilities



Component 2: Tsunami-affected areas

Component 2: Provision of safe potable water supply from existing mobile units during transition.  Train all staff who manage water treatment and pumping units to maximise the sustainable rate of recovery of safe water supplies and to prevent over-pumping and irreversible salinisation of wells and ground water.



Component 3: Tsunami-affected areas

Component 3: Rehabilitation of sanitary facilities in temporary welfare camps during transition.



Component 4: Tsunami-affected areas.

Component 4: Provision of sanitary facilities for new settlements.


6.  Sustainable sourcing of sand


Identify areas where the landward sides of large sand-dune systems could be harvested for sand, or wind-blown sand could be trapped in commercial quantities, without affecting the dunes’ ability to protect the coast.


7.  Policy development and implementation

Component 1: Nationwide

Component 1: MENR, CEA & TAFREN, supported by expert/donor round-tables as needed, cooperate to ensure that environmental concerns are fully integrated in all decisions on national reconstruction, and to coordinate country-driven implementation of all relevant government recommendations.



Component 2: Nationwide

Component 2: MENR, CEA & TAFREN to develop an integrated national policy framework on the management of critical environmental issues arising from the tsunami (environmentally-responsible disposal of debris and solid wastes; extraction and sustainable supply of safe drinking water; restoration of effective drainage to farmlands and urban areas; prevention of deforestation resulting from construction and resettlement).  Develop mandatory guidelines to ensure uniform best practice.



Component 3: Nationwide

Component 3: Enhancing the role of MENR in national reconstruction planning. MENR to be resourced to allow participation in all relevant decisions by MENR officials, by other government officials with special knowledge acting on behalf of MENR, and/or by MENR consultants from the Sri Lankan academic, business and other communities


8.  Building capacity for environmental management


Build capacity of MENR and CEA to conduct EIA and establish monitoring procedures prior to construction of new settlements and infrastructure, through training, addition of expert staff, resourcing to allow the use of national consultants, provision of appropriate equipment, hardware and software, and resourcing to support field work, data and sample analysis and reporting.


9.  Promoting public participation in ecosystem restoration

Pilot Districts and Provinces

Strengthen local authorities through MPCLG to develop and implement integrated local plans at the community, divisional and provincial levels that incorporate options for restoring ecosystems known to help protect against environmental shocks (e.g. mangroves, dunes, reefs and wetlands) and restoring home gardens, plantations, bunds, banks, channels and other features of livelihood significance and also help protect the environments where people live.


10.  Disseminating knowledge


Produce and distribute simple, illustrated guides on how safely to handle, classify and process solid waste and debris, how to design and build improved housing and sanitation using safe materials, and how to identify and correct environmental problems such as blocked land drainage, salinisation, and the spread of alien invasive species.


11.  Mapping coastal zone terrain

Coastal zone

Detailed mapping of coastal zone terrain (up to about the 10 m contour) to support priority setting for coastal defence activities.


13.  Promoting regional collaboration

Indian Ocean and South-east Asian regions

Enable Sri Lanka to participate in regional partnerships that provide access to information, furnish technical knowledge, expertise, guidelines and tools, support capacity building, and strengthen coordination arrangements and access to financial resources.


14. Building national consensus


National round-table discussion on lessons learned from the tsunami and national priorities for restoration and development in the coastal zone.




Total indicative budget





Impact on drinking water supply & sanitation facilities and

rebuilding of the water & sanitation infrastructure

 affected by the Tsunami tidal waves


R. S. C. George

Deputy General Manager (Corporate Planning)

National Water Supply & Drainage Board




The Tsunami tidal waves caused damage mainly to exposed parts of water supply systems.  Water supply services were disrupted in the affected coastal areas owing to this.  Quick remedial action was necessary to resume supply.  Most of the toilet structures were damaged in the affected areas.  Septic tanks in the flooded areas were full.  Again immediate action was necessary to repair the toilets and empty the septic tanks.  Immediate relief activities had to be provided in the affected areas.  This included water supply using bowsers; construction of temporary toilet facilities or repair of existing toilets; enhancement of facilities in temporary/ transit camps; emptying and cleaning of wells etc.


Some people went back to their damaged houses and their water supply facility had to be restored.  Some of our customers were provided with alternate land and they had to be provided with new connections free of charge.  The land use planners identified resettlement areas for the affected people.  Water supply facilities had to be extended to those areas.  In certain areas this requires the augmentation of the treatment works.


Meanwhile several donors pledged their support to assist Sri Lanka in its rebuilding efforts.  The needs had to be matched with the donor assistance.  Arrangements are under way to sign Memoranda of understanding to finance these works.  This presentation covers important aspects of the above mentioned activities carried out by the National Water Supply & Drainage Board.






Tsunami Impacts on Shallow Groundwater and Associated Water Supply on the East Coast of Sri Lanka


Karen G. Villholth,
Senior Researcher, Groundwater Specialist

IWMI, International Water Management Institute, Colombo, Sri Lanka




The major Tsunami of Dec. 26, 2004 that hit many South Asian countries bordering the Bay of Bengal severely devastated the coastal regions of Sri Lanka. A key concern is the nature and extent of the Tsunami impact on the water supply and, in more general, the water resources of these areas. In the coastal areas of Eastern Sri Lanka, the majority of the population, which is rural or semi-urban, is relying on groundwater for their domestic and agricultural activities, most predominantly through traditional private shallow open dug wells in the sandy aquifers. As the Tsunami destroyed practically all wells within the reach of the flood waves, access to freshwater for these people was suddenly cut off and interim alternatives had to be sought urgently in the form of freshwater trucked in from unaffected areas. With the aim to assess and document the extent of the damages and the long term impacts of the Tsunami on groundwater and associated water supply, a field monitoring program was initiated in March 2005 (2.5 month after the Tsunami) in three areas of the east coast. A total of approximately 150 wells were selected within 1.5 km distance from the coastline covering both affected and non-affected wells. Salinity, groundwater level, turbidity, and occurrence of mosquito larvae were monitored on a regular basis, with from 20 to 40 days interval. In addition, salinity levels in sea and lagoon water were measured. Results indicate that  38 % of the wells had been flooded by the Tsunami, with the flooding being more severe in the two most northern sites (48 % in Kallady and 47 % in Kaluthavalai), as compared to the last site (21 % in Oluvil). This pattern could be explained by the way the waves had come in and had been received by the land complex. Salinity levels in wells decreased significantly from the estimated levels at the time of the Tsunami till the start of the monitoring. At this latter point, only 55 % of the flooded wells had salinity levels above an acceptable level for drinking (here defined as 2000 μS/cm), as opposed to 100 % initially. This can be explained by the rainfall that occurred shortly after the Tsunami and the rapid dissipation and mixing of intruding seawater with pre-Tsunami fresh groundwater. As time passed, average salinity levels in flooded wells decreased more slowly, until middle of July, when 43 % of flooded wells were not suitable for drinking. The slower decrease can be attributed to the onset of the dry season and the slower mixing and dissipation mechanisms as concentration gradients decreased. Non-flooded wells showed an opposite trend with salinity levels slightly increasing during the dry season, a generally encountered phenomenon. One half year after the Tsunami, flooded wells had higher mean salinity levels than background, non-flooded wells, indicating that the groundwater still had not recovered fully from the Tsunami.




Pre and Post Tsunami Effects on Vegetation of Coastal Areas

S.P. Nissanka

Department of Crop Science

Faculty of Agriculture

University of Peradeniya




The devastation and destruction caused by the tsunami disaster is not only restricted to damaging human lives and livelihoods but also collapsed the entire environmental, agricultural and social setup of the coastal area of Sri Lanka. In order to provide the relief for the victims of the disaster, the Government has implemented a massive relief programme, with the assistance of international agencies. Related government and nongovernmental organizations have also been attempting to assess tsunami impacts on agricultural and natural environments. Results of a situation assessment study carried out by a group of scientists at the University of Peradeniya and some already available related information are reviewed in here.


Situation assessment results reveled that 82% and 62% of the displaced people are in favor of moving out of the proposed 100 m buffer zone in Hambantota and Amapara districts respectively.  Furthermore, most of the people who wish to move away from the buffer zone wanted to continue their authenticity in the former lands. Regarding future expectations of the affected community both at Hambantota (85%) and Ampara (95%) districts, permanent residence appeared to be the top priority. The job priority (livelihood) seems secondary. It highlights the affected people’s desires on the rehabilitation programs.


Large stretches of coastal region inundated with saline seawater body up to a few kilometer to heights of about 10-30 m at certain places. Severity and the extent of the damages varied with the force of the tsunami waves, topography, land use pattern, vegetation types and the extent of damages caused to sand dunes and corral reef.  In addition to the loss of thousands of human lives and properties, inundation of coast and deposition of saline sediments caused severe damages to natural habitats of terrestrial and wetlands, agricultural fields and plantations, and to soil and water bodies etc. Major terrestrial vegetation types come under the tsunami-affected regions are thorny forest/scrublands, sand dune vegetation, arid zone maritime grasslands/pasture, riverine forests, and semi evergreen forests. The major wetland types are the salt marsh, mangrove, brackish water lagoons, seashore, water hole/tanks, and streams.


It is estimated that the number of farming families affected by the Tsunami was 9048 and the total extent of damage to agricultural land is around 4200 -6000 ha. In most environmental surveys to date, damage to the natural ecosystems was categorized as slight or negligible in most instances except for few cases. Among the different land use systems, paddy farming was the hardest hit mono-crop, next to fruits and vegetables grown in home gardens. The total number of home garden units affected is estimated as 27,710. However, over 50% of the agricultural lands have been successfully replanted several weeks or months after the tsunami.


Study carryout by our team to investigate the impact of tsunami on vegetation and soil salinity developments (over 500 soil sampling sites) in the southern region of different land use types namely; urban and rural home-gardens, rice fields, coconut fields, and plantation and natural forest, revealed that salinity development is not a major problem across all land use types. Majority of the sites are having EC values lower than 4 dS/m. Few areas developed salinity, they are mostly sites where sea water was accumulated for longer period due to topographical setup. These sites may need restoration and recovery attention. However, these sites could be recovered faster if the drainage is improved. As an immediate measure especially for rice cultivation use of salinity tolerant varieties, irrigation and improved drainage facilities together with site-specific fertilization and organic matter may improve the productivity.


Mostly affected species in urban and rural home-gardens are the mango, banana, breadfruit, palmyrah, some citrus spp, sesbania etc. Coconut, woodapple, pomegranate, neem, casuarinas, gansuriya (Thespesia populnea), palu (Manilkara nhexandra) were some species that were not or least affected. Most of the species that were defoliated are recovering. Some species have shown bud breaking and production of fruits with high salt contents (Guava) showing stress adaptation mechanisms. Forested lands and Coconut fields are also having a similar trend. There were a few sites where salinity levels are higher than 4 dS/m (range of 4-10). The trend has been to have slightly higher EC near seashore and decline when moves towards countryside. Urban-homegardens were having soil EC levels well below 4 dS/m casing no real impact on vegetation.

Most of the pandanus and mangrove stands in beachfronts and lagoons were severely affected because these species were the first line of defense in many areas, which took over the full force of the waves. Seashore vegetation cover that consists of mainly creepers is reduced by about 75% in some locations. Debris, sands and sea mud deposited on maritime grasslands, salt marsh and agricultural lands and other land use types. Land use setups such as bunds, irrigation channels, and drainage systems have been badly blocked and destroyed. Massive erosion has occurred and debris left on agricultural fields especially on rice fields pose a problem as the large areas of land need to be cleaned which can be time consuming.

Tsunami waves have pushed seeds of alien invasive species from their coasts farther inland especially in southern region. In some areas, including important national parks, the wave has encouraged the spread of alien invasive species, such as prickly pears (type of cactus) and salt-tolerant mesquite (Prosopis), which have become an invasive and severe threat to the natural vegetation in the Bundala national park. They will definitely spread in an unprecedented rate and become dominant posing a severe threat to our natural ecosystems reducing faunal and floral diversity. In some areas species like Trianthema (sarana), Solunum xanthocapum(elabatu), Avera spp (pala types) are thriving well and spreading very rapidly.

Several studies confirm of many signs of satisfactory recovery; trees knocked over by the wave’s impact and inundated vegetations are regenerating, wildlife including those of elephants and leopards is returning to damaged areas and beginning to drink from ponds that had been contaminated with saltwater but are returning to fresh water.

We learned that the natural ecosystems and barriers such as coral reefs, mangroves, other coastal vegetation and sea-grasses, and sand dunes which we have so casually destroyed were the lifesavers capable of helping to defend our homes, our loved ones and our livelihoods from this nature's more aggressive acts. Several studies also confirm that in those areas with healthy coral reefs and mangroves, the impacts of the devastating tsunami were significantly reduced. Mangrove forests along shorelines are considered critical to halting erosion, but much of growth has fallen victim in recent years to intense coastal development.

Resettlement and reconstruction are now placing a huge burden on natural resources, specially through the location of new settlements in or near ecologically sensitive areas, and increased demand for sand and wood for reconstruction and firewood for brick-making etc. It is therefore vital, that during the reconstruction of shattered coastlines and settlements, the environment is taken into account along with the economic and social factors. If ad-hock, unplanned decisions are taken, it may cause more irreversible damages to the environment than did the tsunami itself.

Tsunami affected many of natural and agro-ecosystems by destroying natural habitats, vegetations in home gardens, plantation crops and forest species and farm fields causing salinization of soil, wells, ponds etc. So far, much of what is known about the environmental damage of the tsunami comes from anecdotal or local reports. Therefore, clear understanding on the nature, severity, dynamics and diversity changes etc, due to the tsunami impacts especially on natural and agro-ecosystems is essential to identify systems that are capable of recover naturally with time and systems that need long-term management strategies to speedy recovery and restoration.