M.U.A Tennakoon, P hD, DSc



Sustaining life is impossible without water. All civilizations emerged and thrived in association with water, running or stored. Worsening of water scarcity was one of the significant factors in the decline of some of the past civilizations. This universal truth has governed the beginning, evolution, rise and fall of civilizations over the centuries. A decline of a civilization is not always the end of that civilization. It can continue to rise and fall intermittently as we have witnessed over the past 3,000 years in Sri Lanka. This study attempts to outline that long trail of irrigation-based civilization, rising and falling like the mythological phoenix bird. These civilizations survived well for several centuries, to begin with, and then declined to a weak existence by going into decadence, but rose again and again from the ashes to have many leases of life in an ongoing cycle.

For the easy exposition, this paper is arranged in five parts. Part I of the essay deals with the beginning of the pre-fifth century B.C. villu civilization that gradually moved into the golden age of small tank construction in the north-central dry zone from the 3rd century B.C. to the 6th century A. D. , the period of decline in small tank construction but reasonably good maintenance of small tanks from the 6th century to the 13thcentury A. D., the dark age of tank irrigation in the dry zone of Sri Lanka from the 13th to the 18th century and irrigation redevelopment in the 19th and the 20th centuries. Part II is devoted to analytically examining the tank morphology in detail. It is in Part III that the small tank irrigation under the British colonial legacy is discussed. The new thinking on small tank irrigation development including that of the Vil Uyana is sketched in Part IV. Finally, the conclusions and recommendations are set out in Part V.


Villu Civilization : the Forerunner of Tank Civilization

During the early Iron Age which lasted till 1,500 B.C. communities of hunters and gatherers in Sri Lanka were living most probably in caves but either in association with streams or villus (natural pools of water) formed in fissures and depressions in the hard rock basement, particularly in the north-western quadrant of the island, in an around the present Wilpattu national sanctuary. Though these people lived in dwellings close to the villus, free and itinerant groups ventured far in to the interior regions away from the immediate villu environment in their quest for hunting and food gathering mostly during the rainy seasons with ubiquitous availability of water, but returned to their villu environment during the dry seasons. At the height of a drought, they may have had water shortages as they were unable to increase water storage in villus by deepening them with their inferior stone implements. However their subsequent ability to use inferior iron implements, seems to have enabled the villu associates to dig the villus and remove at least some small amounts of earth to heap as ridges along the lower parts of the rims of the villus, increasing their storage capacities.

In the mean time, hunting and gathering practices of the villu associates gradually expanded from the north-western part of the island to the western and south-western interior of the north central dry zone, where, instead of a very flat land in the ‘villu country’, they saw an undulating (rolling) land determined by its geology and subsequent geomorphic changes. Those hunter- gatherers in the villu country, through their long time hunting expeditions made to the interior north central dry zone and the little experience that they have already gained in improvement of the villus with crude iron implements that they later had, gave them the start to construct small water pools and subsequently tanks in the interior micro-valleys. That was the genesis of tank construction.

Rise of Tank Civilization

There is no unanimous view as to whether the rise of the tank civilization in the dry zone was slow and gradual or rapid. Senaka Bandaranaike(2000) contends that , “ Sri Lanka’s historical trajectory is a relatively late and extremely rapid transition from the Stone Age ‘hunting-gathering’ to an advanced literate agrarian civilization.” However, it was more likely, that, the change was gradual in consonant with historical developments in India including iron implement improvement , had some influence on the north-western dry zone part of Sri Lanka having had certain agro-ecological similarities with peninsular India. With that influence from India there were several factors that contributed to the evolution of tank development in Si Lanka.

First, those crude iron implements used in India during the early Iron age ‘circa’ 1,500 ‘circa’500 B.C., more towards ‘circa’ 500 B.C., may have found their way to the dwellers in the north-western Sri Lanka, as there were frail boats plying between the two countries across the narrow Palk Strait .As Panabokke (2009) has pointed out, the similarities of agro-ecological regions of Deccan in India and those agro-ecological types(D1 and D2) in Sri Lanka, have readily made it easy for the villu dwellers here to use those iron implements. With the use of those improved iron implements, those people of the villu civilization may have learnt to level up the villu rims better to hold more water in the villus.

Second, the increased familiarity that they gained about the undulating terrain of the western half of the north central dry zone during their repeated hunting and gathering expeditions helped them to try tank construction by blocking the seasonal water paths with earth bunds thrown across them in the valleys.

Third, those hunter-gatherer in Sri Lanka, at least from about the 5th century B.C., if not earlier, getting exposed to the cultivation of dry grains/crops such as gingerly and, kurakkan, first discovered in Uganda and brought here, via Mesopotamia and Indus valley with cotton also picked up from Indus valley, across the Deccan plateau in South India. The story of Kuveni spinning cotton by the side of a villu when she met Prince Vijaya and his entourage is one testimony to the prevalence of cultivation of such crops at least by the 5th century B.C. Rice too would have come the same way but the lands around the villus may not have had suitable irrigable soils developable for wetland rice cultivation. Though earlier, they did not have efficient implements to cut and chop down hard wood trees native to the dry zone cleared forest patches for cultivation by burning away the biomass., The invention of the socket axe in India ,which was brought here, made the cutting down of trees easy, giving birth to the rain-fed chena cultivation and the digging tools such – sharpened but still crude iron bars (craw-bars) also made it easy for the chena cultivators to dig sufficiently large pools to meet their water needs during the rainless days (Panabokke, 2009). The gradual inclination of the villu associates to take to rice cultivation in the western half of the north central region adjacent to the villu country too seems to have prompted them to dig earth and construct tanks in the interior micro-valleys.

Finally, the royals of the first Sinhalese kingdom established in Anuradhapura patronized tank construction, and by the 3rd century B.C. they had engineering skills to construct relatively large tanks like Basawakkulama (Abhayavapi) with previous experience gained through the construction of small tank irrigation systems .More tank construction seems to have become a necessity because of the increase in population demanding more food production from high yielding paddy which requires more water as compared to the low yielding grain varieties adapted to the dry zone.

From about the 2nd century B.C., tank construction increased rapidly. Even some of the interior villus in the north central dry zone were modified to be tanks such as Thuruwula, Kaluvila, Horivila, Ranpathvila, Amaravila, Ratmalvila , Kahapathvilagama and Rotapokuna(pokuna =vila) . Small tank construction was the main focus of irrigation development in the western part of the north central dry zone till about the 4th century A.D. From the 4th century A.D. ,to the 6th century A.D., the rulers of Anuradhapura started showing considerable interest to gravitate to the central part of the north central dry zone ( Nuwarakalaviya) for irrigated agricultural expansion, because that area was blessed with more rainfall than the dry zone’s westernmost part. Their interest in this region was also due to the presence of an undulating landscape having shallow micro-valleys in between low hill ridges ideally suited for building small and medium size tanks. The centrally situated Nuwarakalaviya is the most stable small tank region in the north central dry zone.

The large tank construction era blossomed from about the 6th century to the 13th century, and more so from the 8th to the10th century A.D. which was a period of agricultural prosperity (Nicholas (1959).The maintenance of small tank nucleus in the central region of the north central dry zone, continued amidst the disturbances of the South Indian invader s from time to time and periodic droughts. Historical records such as the Mahawansa (Great Chronicle) in their accounts of great kings have not failed to mention both small and big tanks that they renovated or constructed anew.

Decadence of Tank Civilization During the Medieval Period

There was a significant leap forward in large irrigation construction from the middle of the 12th century with the ascendency of Parackramabahu I to the throne. However, from the middle of the 13th century, following the demise of that great tank-builder king Parakramabahu I, up to the arrival of the British during the late 18th century (1796), was the dark age of tank civilization in the north central dry zone. . The shift of the centers of administration from the great north central dry zone to the southwestern and Hill Country locations in Sri Lanka due to various invasions from South Indian kings from time to time. , The population shift that took place along with the shift of the Capital depopulating the dry zone, internal war-fares for the succession to the throne etc., lead to a wholesale neglect of the north central dry zone by the rulers, making those intricate large irrigation systems virtually dysfunctional.

Naturally, when a centralized administration fails, the centrally administered large irrigation schemes too collapse, but the small village tank irrigation systems managed by the village communities themselves ,remained steadfast to their irrigation management, without letting them deteriorate (de Silva, 1981).Those communities left to be their own in isolation since the 13th century continuously maintained their village organizations , until such time when the rule of the later Kandyan kings became chaotic at best and tyrannical at worst by the 17th century ,in dealing with their subjects. The Kandyan Kings, during the 17th and 18th centuries maintained control of the north central dry zone only remotely through the dissawes appointed by them. Those appointees as dissawes to the remote dry zone were usually not the favourists of the kings. They never or seldom visited the dry zone interior which was gradually swallowed by the jungle. People became the victims of hunger and the wide spread deadly disease called parangi in this desolate and jungle encroached land which was the cradle of the hydraulic civilization of the Sinhalese over a period of 15 centuries. In summary, the north central dry zone remained a God forsaken place for nearly six centuries from the early 14th century until the early British colonial administration during the 19th century.

Even the early British administration did no better than the Kandyan kings to bring solace to those poverty stricken, backward and helpless people who never left the dry zone. Their tank irrigation systems have so deteriorated, that, Robert Knox (1681) tells us that they had no sluices to their tanks to release water properly to their fields downstream .. R. W. Ievers (1899) using information provided by his subordinates has noted that decades before his time of administration in the North Central Province (NCP) the villagers used hollowed tree trunks buried under the tank bunds as sluices. That was the level of deterioration in irrigation that prevailed in the early 19th century !

Resettlement of the Dry Zone

During the whole of 18th century and the early part of the 19th century, there were waves of immigrants from the Hill Country reaching the north central dry zone,. Some of the immigrants gravitated in to the dry zone interior to escape graft of the Sinhalese kings for their wars against the Dutch and the British. Later, those who unsuccessfully rebelled against the early British colonial tyrants too escaped to the north central dry zone to save their lives. In search for safe havens, these escapees settled down in association with the ruined tanks in the north central dry zone jungle with the support of the very thin population of the truly indigenous people ( vanniye minissu),who never left the north central dry zone. They then renovated tanks as they could and started a safe settled life. The landless and poorer Kandyans too followed those escapees to the dry zone.

These new immigrants learnt the art and science of tank-based irrigation systems maintained by those indigenous people and willingly followed the prevailing tank-based rituals, customs and traditions that they inherited from them to ensure the safety of their tanks and their agricultural livelihoods, some of which are still practiced today. Both, indigenous people and the new settlers appeared to have worked in harmony, though the latter desired to live separately as a flock (varige) nearby the village settlements of those indigenous people.. There was no dearth of dilapidated tanks to be renovated or irrigable lands to be opened up downstream of those tanks or to quarrel with each other about the possession of these tanks.

The indigenous people were undoubtedly forest-lovers as they depended on forest resources and chena cultivation, in addition to their dwindling irrigated agriculture. The new immigrants too had a respect for vegetation. They have come from a cooler Hill Country climate accustomed to the dependence on the “Kandyan Garden” type forest resources (highland tree crop farming with least destruction to vegetation). Those who arrived as immigrants in particular did not want the settlements to be very open, as at the beginning, they feared their possible capture by the British to take revenge. Thus, by circumstances, both groups were readily the lovers of closed vegetation around their tanks. Fields and home gardens evolved around a tank-based irrigation system afresh based on the indigenous knowledge acquired from the vanniye minissu, the indigenous inhabitants .


Tank Morphology

Geologically, the wide-based relatively high and continuous mountain ranges at the Matale Foot Hills, which move fanwise towards the north-west, north and north-eastwards, become lower and lower in elevation, narrower and narrower in width giving way to dissected and isolated low rock outcrop lines ,eventually becoming less noticeable earth mounds which disappear in the almost flat coastal plains. The valleys in between those fanlike hill ranges at the start, near the Matale Foot Hills, are narrow and deep and in moving in the same directions as the hill ranges become wider and wider and shallower and shallower, occasionally crisscrossing the dissected low hills, until they too reached the coastal plains. The streams in them moved sluggishly meandering with increasing distance from their places of origin to reach the sea in the north-west, north and north-east of the island (Fig. 1).

Fig. 1

The undulating landscape between the Matale Foot Hills and the north western, northern and north-eastern flat coastal plains there are micro- and meso-valleys mostly with ephemeral water paths ‘etched’ in the valley bottoms (Panabokke, 1999). Determined by geological formations and subsequent geomorphic changes, the water paths in the micro-valleys have taken different shapes – linear, crescent, dendritict and fan-like (Fig 2)

In a micro valley, the main axis stream runs in its keel (bottom). There are very short-lived water paths originating from the side slopes of hill ranges on either side of a micro valley, joining the axis stream in the keel of a micro-valley (Fig .3 ).

By blocking all these streams with the earth dams thrown across the water paths at suitable points, tanks of varying size were constructed, not all at once, but from time to time with the observation of catchment extents available for each tank, increasing volume and flow of water from a head-end to the downstream-end of the valley etc. With all these considerations, when a series of tanks constructed, such a chain of tanks, was known as ellangava where ellan means hanging and gava means next to one another.

An ellangava does not have very rapidly cascading falls from a very steep level to another steep level. In fact, that kind of relief features with violent water falls do not exist in micro- or meso-valleys in the north central dry zone. The whole gradient of an ellangava  may be only a few inches for a km. Therefore, even in a fifteen km long ellangava , the gradient will be only a few feet, not warranting the use of the term cascade(Fig. 4) .

This term cascade seems to have been erroneously borrowed from the Cascade Mountains with rapid waterfalls in the Rockies Mountain Range in the United States. This serious error needs to be corrected, and in place of the term cascade, we need to use the term ellangava which is an age-old term that was well entrenched in the minds of our fore-fathers as emphatically stated by Tennakoon in 1999 and accepted by Panabokke 1999).

ELLangava Defined

An ellangava is a very low gradient sluggishly moving water path from a head-end of summit of a micro- or a meso -valley to its lower-end at a large reservoir or a large secondary stream (Oya), filling a chain of tanks one after another on its way down , gently spilling over the tanks’ excess water into long flat plains in between the tanks and in that whole process, the tanks accumulating, preserving, releasing and guiding water to downstream fields for irrigation.

In the 457 ellangavas in 50 sub-water basins of the nine river basins in the Rajarata (north central dry zone), more than 4,000 tanks have been identified. Some very small ellangavas are single tanks like that of the Pul Eliya near Medawachchiya. Many have several tanks in each. There are the larger ellangavas with 20 to 25 tanks. However, the modal value calculated is 8 tanks (Panabokke, 1999)

Land Use Zones in a Tank-based Village Settlement

Putting together the pieces of records available in village files maintained in the Anuradhapura Kachchri( District Secretariat), Final Village Plans (FVPs ) prepared by the British Land Officers, diaries of the British Government Agents ,people’s petitions submitted to the Government Agents and the author’s field work conducted in 30 randomly selected villages in the Anuradhapura District in 1973/74 have enabled to present a fairly accurate picture of the small tank- associated land and water use in a model form (Tennakoon, 1974). As could be seen in the schematic model in Fig. 5 , an entire settlement’s land use consists of five zones – the tank, the old fields ( purana vel) immediately downstream of the tank, field blocks (akkaravel) developed on the sides and at the bottom of the old field, parkland around akkaravel and finally the forest.

The boundary, the extent and the size of each zone can vary in accordance with the relief of the land (Tennakoon,1974). In this holistic approach all the villages with their respective land use zones are viewed as one composite ellangava mosaic. Though Tennakoon (1974) has described the connectivity of tanks, in his tank-field-tank-chain system amplified (Fig. 5B), it was Panabokke who very clearly demonstrated this connectivity later in another simple schematic representation in 1999 ( Fig.3) above.

Tank Components.

Once a tank bund was renovated and the tank was filled with water, the trees growing in the tank bed over centuries naturally rotted. However, people’s interference with the tree girdle left right round the tank water body was very minimal. A village tank had a tree girdle (gasgommana) around its water spread area, which, as an effective wind shield minimizing surface evaporation from the tank aided by dry winds under the scorching heat of the sun during the dry season.(Fig.6A , Fig. 6B)

Fig. 6A : Wind-swept Dried Upper Tank Bed of Alisthana

Fig. 6B. Dried tank bed of alisthana in the hottest month of September 2014

In addition to the minimization of evaporation losses by maintaining a tree girdle (gasgommana) there are two other strategies followed to prevent  silt accumulation in tanks and thereby keep the tank storage capacity from diminishing. The first is that if the tank is a large one, rapid water flows in to it are blocked with small bunds upstream of that large tank not very far from its upper shore line mark (Fig.7).

Water bringing soil sediment in solution, suspension and even by dragging gets those sediments deposited in these silt trapping small tanks called kuluwew and water relieved of sediments spills over at both or one end of a kuluwewa bund ,finding the way to its normal path again, leading to the large tank below. The second method is the maintenance of a reed bed known among villagers as perahana along the upper shore line of a tank to filter the sediments brought in suspension and dragging as well as dried leaves and other dry vegetative matter floating in water. Over the years with increased density of reeds in the reed bed, makes it a haven for the wading birds and micro-organisms. Those micro organisms are food for the shallow water loving small varieties of indigenous fish and all preying birds (Fig.6)

In the past, tank water was not allowed to be polluted indiscriminately. It was treated with respect all round. Water was even worshiped at times of tank rituals. Washing clothes and bathing animals inside the tank was prohibited. They were permitted downstream of the sluices canals in designated water spots. In a village tank there was a specially designated spot to collect drinking water, some distance away from the common bathing spots (nana mankada). Those suffering from infectious diseases were never allowed to bath inside the main village tank. These cleanly kept water bodies enabled the enhancement and protection of a rich tank-based biodiversity .

While the water inside the tank was so carefully kept clean, there was an age-old device for releasing water from the tank for downstream field irrigation. The water was filtered and cleaned, as much as possible. An elongated murky meadow (kattakaduwa) with turbid water at the outer toe of a tank bund was maintained for the filtering process.(Fig. 6).Over the years, when the bottom water in a tank accumulated alkali substances such as soda, potash, ammonia that combined with acid seeping downstream under the tank bund in capillary action to this meadow, that water is captured and held there. Salt succulent plants such as mi (Bassia longifolia) , kumbuk (Terminalia arjuna), lunuwarana (Creteva adansonii), thimbiri (Diospyros malabarica), val beli (Lumnitzera litterea ), and vetakeyya (Pandanus kaida) were grown along the rim of the meadow for their easy and continuous sequestration of salt/alkali in water in the murky meadow. By this process, the alkali contents of water that is likely to flow down readily to the downstream paddy fields were reduced. These trees when grown densely together, form another tree-line shielding from dry wind from the tank bund side as well. Paddy fields, parklands and stream sites also had at least limited numbers of trees spared.

Water distribution to field blocks and allocation of water to differently owned field strips (pangu) though appears as a mind- boggling intricate network system, it actually had a definite order and sequence in release and distribution of water to all the fields ( Fig.7).

The best study of land ownership and provision of water to the shareholders in the Old Field with a clear diagrammatic representation was first published by R. W. Ievers in 1899. Ievers had distinctly shown canals taking down water from the sluice, the distributor canals taking water from the main sluice canal to different field units in the Old Field such as the upper-end and lower –end fields of the Old Field (elapath), the different field portions of the Old Field( baaga) and the small units of field portions ( issara) and from each field unit the distributor field channels called veli,(which should not be confused with the term used for “dams” elsewhere in the country). A field unit channel   had inlets (vakkadas) to each field strip( Panguva) . The whole field irrigation system is an ingenious method in itself, where limitedly available water is made to flood thinly over a vast area, artificially creating a wetland environment in the dry zone.

The tail-enders (pahala pangukarayo)in a field unit (issara) had the right to impound their land shares with water first and thereafter the head-ender land holders (Ihala Pangukarayo). They all are required to ensure that the field ridges are well mended shielding water leaks from them particularly through crab holes (kakkutu uma)in the field ridges leading to unnecessary waste of water from the cultivated fields as vel pahu watura meaning water leaking out of fields, which, in any case, though a loss to those fields, will be a re-cyclic gain to the tank below that itself has fields downstream of it to irrigate.


Ignoring Small Village Irrigation : A British Folly

The intricate system of environment friendly irrigation system  described   above was not only virtually left to its own by the British rulers in the 20 the century but was also under-estimated and sometimes ridiculed .This is evident in a statement made by J.F. Kennedy, Director of irrigation in the 1930s. He had the audacity to declare wildly that, ‘The small tanks are so rampant like the herds of stunted village cattle and useless like them” (Brohier 19… and Mendis 19 ). If small tanks formed the backbone of the hydraulic civilization of Sri Lanka until the 6th century AD, that was before the move of the Sinhala kings to construct large tanks, how could they be considered “useless”? How did those small tanks continued l to serve the villagers well even at the time of the British administration? That thinking seems to have been fashioned by the proponents of large tank development to grow more food to be self sufficient in rice. In keeping with this tune, the Irrigation Department became a powerful lobby for large tank development. Though S. Arumugam as Director of Irrigation raised a dissenting voice in 1957 emphasizing the importance of village irrigation works, it was insufficient to “mount a real challenge to the Large Tank discourse”(Siriwardena .2014) .Even in this faint voice of Arumugam he has only looked at the tank and village settlement and restrictedly cultivated only paddy fields. He too has failed to penetrate deep in to the total ecosystem mosaic of the ellangava- based tank system .

The British strategy of ‘divide and rule’, the moral subjugation of the subjects that they ruled over, and their arrogant emphasis placed on large tank development with the tacit approval of the politicians in power were three indirect but powerful causes for the stagnation of small tank development. The consequence of their ‘divide and rule’ strategy between the small tank irrigation and large reservoir development haunts us even today. The indirect subjugation of the once community managed small tanks caused in the Waste Land Ordinance of 1831 with the declaration that all continuously uncultivated lands belongs to the Crown , compelled the helpless villagers to be cocooned in their clustered mud-hut village dwellings ( Gangoda) and work small extents of land with subjugation to that arrogant colonial order, ‘do as we say, not as you want’.

The Large Tank development emphasis, more so in the 20th century before independence, continues   even to the present day in both our political machinery and in the irrigation bureaucracy. The irrigation bureaucracy remains the hardest to penetrate and canvassing for a fully-fledged small tank development strategy was always made to remain elusive. However elusive it is, that is the convincing way to make, at least some parts of the dry zone wetlands, with people’s total involvement at much lower costs, over a period of time, but not by large irrigation systems at ‘astronomical costs’ (Siriwardena. 2014). Even long after gaining our political independence in 1948, we are not ready to cast away the coat of that colonial legacy. Thus far, mostly what we were doing is darning the torn areas of that colonial over-coat and shamelessly continuing to wear it over the past 57 years in respect of small village tank irrigation development. This is the inconvenient truth.

Post-Independent Irrigation Policy Changes Made and Their Consequences

In addition to all   those hindrances, with the transfer of small tank management to the Department of Agrarian Services in the 1960s, it has done only a little to maintain small tanks properly. Kattikepeema the collective community device used to regularly remove silt from tanks, which was an age-old practice came to a halt, making an every body’s responsibility, a no body’s responsibility. The tanks are still getting silted since the1960s causing irrigation shortages with the imperceptible reduction of water storages in them. For some of the village level irrigation officials, particularly the Technical Assistants (TAs) of the kind, there is nothing more important   other than taking elusive contracts by themselves in the names of their trusted friends or relations and doing the work all by themselves or contracting the work to those who give a “something” (a popular phrase now in the common parlance). Needless to say, that, some of the works that they completed are below the required standards, be they the tank bund improvements or removal of silt from tanks or irrigation canal/channel improvements. Had silt in these tanks regularly (annually) been removed and bunds been regularly maintained, the tanks would have more water today and thereby more paddy production as well as a more wetland  expansion.

Forest Butchered

While the effect of small tanks in keeping their surroundings as wetlands diminished, due to siltation and reduced storage capacity resulting from the poor maintenance of tanks over the past several decades, income from irrigated paddy cultivation also diminished. As a result there was a rapid increase in the destruction of forests in the dry zone particularly during the  chena cultivation rush in the 1970s. This was the decade that Sri Lanka faced a serious foreign exchange difficulty and a looming world food shortage compelling the country to grow more subsidiary food crops in non-paddy growing lands. The importation of chilies was banned altogether along with several other subsidiary food crops, which sent the price of chilies in particular, astronomically high in the market. This lead to a boom in cultivation of these crops in chenas clearing the forest in any space where there was vegetation to slash and burn. Most of the chena cultivators were new ‘invaders’ who knew nothing about the traditional eco-friendly systems of forest clearing , leaving all possibilities to foster rapid re-growth of vegetation when chena is abandoned. Literally, they butchered the forest indiscriminately for cultivation of chilies. The consequence was that in about three   successive years of chena cultivation, vast tracts of forest were destroyed so much so that tracts of land separating one village from all other villages located at considerable distances were wide open facilitating dry winds to travel great distances and further increase the rate of evaporation. This can be equally if not more devastating than drought conditions not uncommon in the region. However, this problem still remains ignored.

The damage caused by destruction of forests did not stop there. It accelerated soil erosion in lands stripped of their vegetation, increasing the loads of eroded   soil moving into water bodies (in solution, suspension and even by dragging and depositing silt in tank beds). , The reduced tank storage capacity, in turn, threatened the irrigated paddy cultivation, in terms of crop losses or non-cultivation of once cultivated lands due to water shortages. The end result of all this, is that the dry zone is getting drier, and at least a part of it is imperceptibly moving to be a desert margin (Tennakoon, 1979). This has not received even the slightest attention  from the due authorities over the past three and a half decades!


New Thinking and New Experiments Emerged

In the 1980s and 1990s there was a growing interest in studying ellangava related subjects (but using the erroneous term cascade for ellngawa at that time) by different scholars from the standpoints of their chosen disciplines. Most of the studies appeared as journal articles, seminar papers and booklets both in English and Sinhala around the turn of the century (Panabokke, 1997,1999,2000,2002,2004,Tennakoon, 1974, 1979 ,2000,2004,2005 and 2012)

Apart from those presentations, there were rather cautious attempt made by the development functionaries with or without the involvements of the professional to make ellangava -based physical development efforts in several parts of the country. Under the Youth Settlement Programme launched in 19….there was an adventurous experiment conducted in Kiul-kele in the Puttalam District where many abandoned small tanks were renovated to store seasonal rainwater in them which would have otherwise freely flowed away. Using this water , field irrigation was improved on a restricted scale . The experiment proved more striking because the groundwater level artificially increased around those renovated tanks facilitating a healthy growth of tree crops enhancing the income of the youth in settlement . With the end of the Youth Settlement  Programme in 19 ….the tank maintenance fell apart (Siriwardena, 2014) However, a recent evaluation of the project, though belatedly completed in 2014, showed that the once promising development was environmentally on the decline (,,,,,,).

With the intervention of the Mahaweli Development Authority, partial silt removals were carried out in Pulanchiya and Maha Galkadawela tanks in the Galgamuwa and Giribawe DSDs respectivelyin the Kurunegala District. Their water storages increased facilitating two seasons of paddy cultivation in place of raising a single crop a year prior to the silt removal.

Two other experiments – one in the Kapiriggama cascade in the Rambewa DSD and the other in the Nuwaragam Palatha DSD both in the Anuradhapura District have been taken up for ellangava-based development , the first by IUCN and the second by Plan International.

In 2014, under the aegis of UNDP Sri Lanka, and with financial support from the Global Environmental Fund (GEF), and South Asia Partnership Sri Lanka (SAPSRI) a ‘Tank-biodiversity Improvement and Protection Project’ with seven specific objectives was launched. (Fig. 9A and Fig. 9B and Box 1).

Fig. 9A Tree planting in Alinthana to review Gasgommana

Fig. 9B. Re-development of of Alisthana Kattakaduwa (see Fig. 7)


Box 1: Alistana Tank Biodiversity Enrichment and Protection Project, 2014 – 1016

The seven specific objectives of the project are: (1)resuscitation of the tank’s (gasgommana); (2).improvement of reed beds (perahana) ; ( 3.)revival of the meadow (kattakaduwa); (4) fish breeding in the tank; (5) home garden vegetation improvement with tree crops of commercial value; (6) encouragement of the cultivation of chemical fertilize-free indigenous paddy varieties; and (7)farmer-institutional development in the village for sustainable management of the     activities ( 1) to( 6) stated     above, the essential tank-based component development for the benefit of the people. Anyone can visit Alisthana at the112th KM post on A-9 road and see and understand how a small village tank’s biodiverse environment can be resuscitated with maximum social and economic benefits accrued to the villagers. nvironmental education for the senior school children. The sole intention is to saw-. There may be similar ellangava- based development efforts already made and are being made else- where .

Vil Uyana : A Unique Case

The, centuries old dry zone-based hydraulic civilization had its phases of glory and decadence, the last being the deterioration of small tank maintenance set in after the Agrarian Services Department took over them for maintenance in the 1960s, while the whole irrigation development policy craze remained heavily bent on the development of large reservoirs. In this background, the total environment friendly Vil Uyana development, as an integral part of that fanlike ellangawa to which it belongs (Fig.8) emerges as a revolutionary creation of two small water bodies intelligently in place of traditional tanks encapsulating the tank’s environmental components in a small extent of 25 acres, with suitable adjustments.

It has modified adaptations of a tank’s tree girdle (gasgommana) and fixation of silt trapping reed beds (perahanas) suitably at the water’s edges round the two main lakes, mitigating evaporation loses caused by dry winds and controlling silt accumulation in the lakes respectively. The reed beds have become the havens of wading birds. Indigenous fish varieties and many other water-associated creatures including micro- organisms are in plenty in these lakes. Within this  enchanting natural environment visitors can experience a relaxing atmosphere as they leisurely stroll around a small tank in its natural setting in the dry zone, admiring its aquatic biodiversity while enjoying its cool and soothing comfort.

In other words, the environmental architecture of Vil Uyana has captured almost a greater part of a tank environment in a nut-shell ,with modification of tank features where necessary. The ameliorating climate that has been created in this small Vil Uyana property which is an integral part of a vast hot and dry land expanse. This confirms, that, a careful water and vegetation management with suitable modifications to fit in to a particular location, provides the key to an integrated tank-based environment-friendly development, transforming the dry zone in to a wetland is possible.

Additionally, Vil Uyana has carefully replicated the paddy fields, water inlets and outlets, forest patches, some forest habitats,  chalets reminiscent of the traditional village dwellings taking necessary cues from them in their alignment, internal utility of space and even the use of house construction materials. A chalets in Vil Uyana is a careful architectural blend of traditional and modern house construction aesthetically providing all living comforts inside with a mass of rich biodiversity surrounding it. To repeat, Vil Uyana is an environmental architect’s brilliant resurrection of the centuries old small tank environment which should open the eyes of all those who contemplate the transformation of the dry zone into a wetland.



Small tanks existed in this county for a period of well over 2 500 years with suitable adaptation to the nature of the undulating terrain and the rainfall regimen of the dry zone with intermittent periods of prosperity and decadence. They formed the bed rock of our hydraulic civilization playing a formidable role even at times of greater focus on large tank constructions in the distant past and even at present. The livelihood of a large population in the dry zone, then and even now, depends on small tank-based irrigated farming .It will continue to be so in the foreseeable future as well, because of its vital role in food production even if the livelihood opportunities in non agricultural livelihoods would increase. Therefore, the prevailing over emphasis on large tank development hypothesis, ignoring small tank development, is unacceptable.

In the 1960s a separate entity called the Department of Agrarian Services was set up. It failed to meet the expectation of making the small tank sector a vibrant development force. The depressing part is that, in spite of what little that this department has done in proper tank management, the water storage capacities of small tanks continued to dwindle due to scant attention paid to the maintenance of tree girdles (gasgommanas) as wind shields, the lack of proper removal of silt accumulated in tanks over the past several decades, negligence of the time-tested devices in the past to arrest the free flow of silt from the catchments of tanks such as the maintenance of kuluwew and reed beds along the upper shore lines of tanks, lack of attention paid to protect kattakaduwa that prevented the polluted water seeping down from the upstream tank without letting it freely in to the paddy fields further downstream of tanks, neglect of irrigation canal and channel systems feeding water to the cultivated fields, poor maintenance of tank appurtenances used in water management all round and the top-down hierarchy of officials tending to impose orders to the irrigation beneficiaries at the grassroots level. Furthermore, the development proposals coming from bottom upwards to the higher echelons of the department are seldom approved reluctantly after much dragging of feet. In the mean time, a few professionals interested in the dry zone development began to stress the need to adapt an ellangava- based total development relying on small tank irrigation. This idea was pioneered by Tennakoon, (1974,and 1984) and Madduma Bandara (1985) soon followed up by Panabokke(1999), and several other professionals joined the fray in the 1990s and thereafter. With the support of these professionals and even with their involvement there appeared some field testing of the ellangava-based development hypothesis in several isolated locations in the country, some of which have been briefly referred to earlier. Of these, the Jetwing Vil Uyana experiment stands unique. It has retained some of the time tested tank appurtenances and tank water protection devices anew, with requisite modifications to fit into its small extent of land. Vil Uyana has successfully mitigated the usual hot and harsh climatic conditions in its atmosphere with the protection and enhancement of the natural vegetation , signaling that a climatically harsh dry zone can be intelligently transformed into a wetter land over time with proper interventions propagation and protection of flora and fauna. It heralds a green light for the future dry zone development that should not be ignored.


The dialogue on ellangava– based dry zone development that emerged during the past few decade still remains rather fragmented. Only small groups of professionals and development functionaries got together to have dialogues often in isolated small groups. Seldom were they followed up by wider circles of development functionaries.

The universities need to spear-head broad- based   discussions involving the subject matter specialists, academicians, university students and relevant development functionaries in a large number of government departments not missing the departments of Irrigation, Agrarian Services, Forest, Meteorology, Land Settlement and Agriculture in particular, ministries such as the Disaster Management ,Authorities like the Mahaweli Development, Boards like Water Resources Development and representatives of any other relevant organization.

To make these dialogues more meaningful, the universities are invited to closely study those isolated experiments undertaken in many locations in the dry zone, some of which have been already referred to in this study to draw useful conclusions from them in understanding where they have gone right or wrong and what limitations that they faced in their pioneering efforts and what facilities they would require—knowledge, technical support, new inventions, beneficiary support and more importantly financial support – to foster the ellangava –based total development in the dry zone

It is important to ‘learn from the people, at the grassroots level who have the traditional knowledge of small tank-based dry zone development. There should be a continuing dialogue with them to understand their views which should be documented to disseminate that information to the general public and decision making bodies directly and through print media and electronic media such as television, internet, social media (face book and twitter) for the benefit of the younger generation.

With these brief but specific suggestions made above, a strong recommendation needs to go to the government followed by strong lobbying to formulate <strong>a national policy for small tank-based irrigation and land use development,</strong>. This is called for, because over the past half a century, under the control of the Department of Agrarian Services, the small tank development in the dry zone which is the food granary of the nation and the home of a significant percentage of the country’s population (several millions), has not made any significant headway.