Poor rainfall throughout Sri Lanka during the past few months has caused a drought unheard of during recent history. Particularly affected Districts are Kurunegala, Puttalam, Anuradhapura, Polonnaruwa, Batticaloa, Ampara, Nuwara Eliya and Badulla.
Farmers complain that their crops are being ruined or are on the verge of being ruined. Some villages complain of the shortage of drinking water. The Government warns people of the possibility of having to restrict water issues under water supply schemes and request not to use issued water for other than domestic purposes.
The CEB complains that a shortage of water in reservoirs has reduced hydropower generation and of escalating costs due to higher quantities of power having to be purchased from private power generators.
Foreigners, who observe the rainfall records of Sri Lanka however, ridicule our so-called arid regions of Hambantota and Mannar. In most countries in the world, the average annual rainfall received is very much less than those “arid” regions.
In the past, droughts occurred mostly in October and November when the Maha season rains affecting the North, Eastern, and North Central Provinces get delayed, and occasionally when South Western monsoons get delayed with few rains in April, affecting the South and Western part of the country. The current poor rainfall during months of May and June is unheard of during recent history.
According to the Meteorological Department, the percentage of rainfall received up to the end of May compared to the average rainfall has been as follows.
North Central Province: 70%
Farmers in the North-Central and Eastern Provinces complain of the destruction of their cultivated paddy and vegetable crops due to the non-availability of irrigation water. According to the above data, North Central Province having received 70% of normal rainfall should have been the least affected. However the farmers in Anuradhapura area especially in Mahaveli System H have been most the vocal.
Normally the Maha rains in the north and east commence in mid- September, seed paddy is sown in October, with harvesting commencing from early January. The Yala season cultivation can begin in mid-February with harvesting by late May or early June. Therefore the requirement of irrigation water for paddy fields from the latter part of May is minimal. Then how did the water shortage affect the farmers so much?
The only explanation is that the farmers delay their cultivation and during the delay precious water has gone waste down the irrigation channels. Or did the farmers cultivate a third season between Yala and Maha. If so, with irrigation authorities being aware of the water availability in tanks, why did they allow farmers to cultivate a third season?
For almost half a century, the irrigation water in Mahaveli System H, originated with the construction of Polgolla Dam across Mahaveli River in mid 1970s, when water was diverted to fill Kalawewa and Rajangana Wewa. The diverted waters feed System H and the balance is diverted to feed the tanks in Anuradhapura. Over the past decades the farmers of the Mahaveli H zone enjoyed plenty of water without restrictions.
Today, there are serious allegations from the cultivators and farmer societies as well as from politicians for reasons for the shortage of water. In a recent newspaper report a member of a farmer society questioned: At the beginning of the Yala cultivation season, all tanks in the area were full. What happened to all that water?
Another came with the answer: Most water in Kalawewa was diverted to Anuradhapura tanks for the Poson season, when thousands of people flock to Anuradhapura and Mihintale. Every-one saw over the TV, pilgrims bathing in and enjoying the tanks in Anuradhapura, with life-guards in attendance. Few realised that the enjoyment was at the expense of the farmers.
Another cultivator remarked that when farmers were settled in System H in late 1970’s, certain sections were ear-marked for the cultivation of only subsidiary crops. A few years later due insistence of politicians, they too were allowed to cultivate paddy. Over the years, more and more areas in System H were added for paddy cultivation and were supplied with Mahaveli water.
During the past few decades farmers in North Central Province, especially in System H did not experience any water shortages. In fact they were used to having ample water far in excess of their needs, and got used to wasting water.
Another beneficiary of excess water from Anuradhapura is the farmers in Mannar, who cultivate paddy under Giant’s Tank. Malwathu Oya, flowing through Anuradhapura town discharges waters to the sea south of Mannar. The waters of Malwathu Oya are diverted to feed Giant’s Tank close to Mannar, located in the driest sector of the country.
Most of the catchment areas of Malwathu Oya are lands of Anuradhapura District, rains as well as excess water discharged from paddy fields from Anuradhpura West and Rajangana areas flow into Malwathu Oya.
Normally the quantity of water diverted from Mahaveli to Kalawewa is vastly beyond the requirements of paddy cultivators, to the extent that when rains arrive, tanks in Anuradhapura District overflow creating floods, as tanks were already filled with Mahaveli water. The quantum of wastage of water from paddy cultivation is so high, that during the past few years, on a number of occasions Giant’s Tank too spilled over due to excess water.
Proper usage of rain water
Our ancient Sinhala kings built irrigation tanks in the dry zone, Anuradhapura and Polonnaruwa areas which were extensively cultivated with paddy and even exported rice with the efficient use of rain water. Historically the farmers were supposed to cultivate Maha season with rain water, collect and store rain water in tanks for issue during dry months and only deficiencies are supplied from tanks.
Normally in Anuradhapura area, Maha rains commence around 15 September and prior to the rains the fields are dry and hard, with field bunds damaged due to machinery running over them during harvesting and transport. The first rains soften the ground and farmers can repair damaged field bunds, the second and third rains collect water in the fields and ploughing is made possible.
Currently almost all ploughing and preparation of fields for paddy is done with machinery, requiring less water and time. Therefore the release of water for land preparation can be reduced by at least 60% during Maha season and further reduction is possible with curtailment of water issues during rains.
If a farmer is unable to complete his land preparation in time, he could always use a faster maturing variety of rice and still harvest with the other cultivators. Therefore it is possible to reduce usage of water by at least 50% during the Maha season for paddy cultivation without a reduction of crop yield.
Irrigation and hydropower from Mahaveli
Kalawewa built by King Dhatusena was in existence for over a thousand years, storing rainwater for the paddy farmers. With construction of the Polgolla Dam, part of the Mahaveli waters were diverted, Kalawewa storage capacity was enhanced and additional paddy lands were opened under the Rajangana Scheme and other minor tanks.
While part of the water being diverted from Polgolla dam, the balance water was to generate power at Victoria, Randeniga and Rantembe who were supposed to use the same water in cascading generating plants. Under the Accelerated Mahaveli Project, the Victoria Power Plant Stage I was constructed capable of producing 210 MW of power.
After completion of Kotmale dam upstream of Mahaveli, Victoria Power Plant Stage II was to be built capable of producing further 210 MW of power. In the planning stages, the quantity of water flowing in Mahaveli was calculated to be sufficient to feed System H, as well as to generate power at Victoria Stage I as well Stage II. Then what happened to this water?
According to CEB, the production of power from Victoria Stage I, less than half the capacity, the reason being most water is being diverted at Polgolla feeding Kalawewa and is being wasted. With insufficient water to run Victoria Stage I, how can one even dream of Stage II?
What happens to excess water?
With normal rainfall, the irrigation tanks which were supposed to collect and store rain water, lack the storage capacity, as they are already full with Mahaveli waters, spill over creating floods. This happened in late 2010 and early 2011 where flooding happened on three occasions, even in April 2011 during the height of normal dry season.
At the cultivation committee meeting, farmers agree on a cultivation programme, which prescribes a period for release of water from tank and farmers are expected to prepare the fields and sow their seed paddy by the agreed date. But invariably this date is extended due to various influences, meanwhile irrigation water flows down the canals, wasted.
In allocation of lands in System H, farmers in some sections were specifically informed that they would not be allowed to cultivate paddy and they were expected to cultivate other crops. The reasoning was the land in the particular section was sandy and irrigation water would get soaked down, consuming huge quantity of water. These sandy soils are ideal for subsidiary crops. But later politicians have allowed cultivation of paddy in same lands.
Warning from World Bank
During the planning stage of the Mahaveli Development Project in the late 1970s, the World Bank pointed out that Sri Lanka’s rice farmers consume the world’s highest volume of water for an acre of paddy cultivation and warned that unless this consumption pattern is curbed, the entire Mahaveli Project would become a failure.
Studies were carried out to ascertain the water requirement of paddy, and researchers discovered that rice plants could grow without substantial loss of crop output, even when water is provided once in six days. Agriculturists proposed water is issued to fields every fourth day and the irrigation water distribution system for paddy fields in Mahaveli System C were designed accordingly. But the farmers prefer to keep paddy fields inundated for weed control purposes, which consumes a huge quantity of water.
As the World Bank officials noted, water needs intelligent distribution between irrigation and power for the best interests of the country. World Bank staff observed our farmer cultivation practices and warned that the prudent usage of water is a pre-requisite for successful implementation of Mahaveli Project.
SRI – Cultivation of rice
The System of Rice Intensification (SRI), a method of cultivation of rice started in Madagascar in 1983 as a methodology aimed at increasing the yield produced in farming with lesser input. The method was popularised by the Food & Agricultural Organization (FAO) during 1990 to 2005 as a way of cultivation of rice which consumes less seed paddy, water, chemicals and expenditure, but giving more in yields.
The promotional works were done in Sri Lanka too, encouraging the usage of compost, but chemical fertiliser usage is also possible. The rice seedlings are planted in 10” by 10” spacing allowing weeding to be carried out using a manually operated weeder (a small machine which does not use fuel which could be locally manufactured).
The cultivation method is ideally suited for small holdings in Sri Lanka, where water is supplied by smaller tanks, as a way of saving water and at a lower cost increasing income of small farmers. But SRI method involves 50% more labour for transplanting of seedlings and weeding is best suited where family labour is involved.
Currently this method is not being popularised by the Agricultural Department, probably as the method does away with usage of weedicides and pesticides, which would not to the liking of agro-chemical companies.
A few weeks ago, newspapers highlighted illegal tapping of water in Nuwara Eliya from Lovers’ Leap waterfall. The photographs showed two PVC pipes carrying water from the waterfall. People alleged that one of the reasons for shortage of drinking water in Nuwara Eliya is the illegal tapping of streams.
Throughout the hill country, from the coastal base where mountains commence, lands are blessed with small streams bringing water down from the mountains. These thousands of riverlets collectively produce streams which extend into rivers. These small streams are tapped by the locals, either from a small natural pool or a constructing a pool by obstructing the flow with a few rocks and cement.
Water from the pool is taken through a PVC pipe to each individual house and is referred by the locals as Bata line. These Bata lines supply water to a concrete or brick tank built on the ground at a higher elevation than the house or supply water directly to the house. The writer has seen hundreds of these Bata lines, but yet to see one supplying to a tank fitted with a ball-valve, preventing overflowing when full.
Most of these lines continuously discharge water and no one cares. Locals do not understand the gravity of what they do; even the Government officials in the area, who notice the phenomenon every day are so used it that no one remarks on the waste. Only a few people of the country are aware of the extent of wastage of water from minor streams by the thousands of Bata lines and the harm they do to our precious water supplies.
Learn from mistakes
It is clear that the South-Western monsoon has been poor. But the problems encountered by the farmers could have been greatly reduced with proper cultivation practices and the intelligent use of water.
Finding faults will not provide solutions; history is important to learn lessons so as not to repeat same mistakes. If we could look rationally of happenings in the past, we could convert the current drought into a blessing in disguise. Let us see what could be done.
Use maximum rain water
From the time of ancient kings, the Maha season cultivation was carried out with rain water, storing rain water in tanks for the Yala season. We could get back to the same practice.
With the current method of ploughing and preparation of fields for paddy with machinery, the requirement of time and irrigation water is less and initial land preparation and cultivation can be with rain water.
As such, the release of irrigation water for land preparation can be reduced to a minimum during Maha cultivation season. Tank water should be reserved for Yala cultivation and to cover up shortages.
Cultivate on time
As preparation of land, as well as harvesting in done with machinery, the period allowed for land preparation could be reduced. Maha season cultivation can commence immediately after first rains and Yala season, just after harvesting of Maha crop.
The reduction of time will reduce the quantity of water issued from tanks. The early completion of Yala cultivation will allow a third crop, such as maize which does not require irrigation water.
Divert limited waters at Polgolla
As warned by the World Bank, Sri Lankan farmers use the highest quantity of water in the world and during the past decades, usage would have gone up further. We have neglected results of proven field trials conducted decades ago to control wastage of water in paddy cultivation.
Diversion of water at Polgolla needs to be as per original calculations done during planning of Mahaveli Project to supply needs of System H. This will force everyone to reallocate water issues and conserve.
Produce subsidiary crops
Water issues to Mahaveli System H would be only for the farmers designated to cultivate paddy at the time lands were allocated. Others who were allocated land for subsidiary crops as the lands were sandy and unsuitable for paddy cultivation should be told to return to subsidiary crops.
Weaning of farmers from paddy to other crops especially in Yala season, needs to be popularised among the farmers in other irrigation schemes too. Sri Lanka having reached self-sufficiency in rice, the farmers need to be encouraged to cultivate more subsidiary crops as chillie, potato, onions, soya bean, ground nut and maize which consume less irrigation water, especially on marginal lands.
Due to excessive diversion of water at Polgolla hydro-power generation at Victoria, Randenigala and Rantembe remains well below full potential. Much higher hydro-power production could be achieved by diverting only the quantity of water originally planned for diversion at Polgolla and allow balance for power generation.
Victoria Stage II
Today the country’s bulk of electricity supply comes from thermal power and the hydropower potential of the country has been exhausted, except for a few minor hydropower locations. Victoria Scheme Stage II was planned for construction after the completion of Kotmale dam to stabilise water flow. Stage II was to enhance hydropower by further 210 MW and the planners were well aware of the sufficiency of water in Mahaveli River for cultivation purposes as well power generation.
It is the responsibility of all Government agencies and farmers to get together in controlling waste of water in paddy cultivation and construct Victoria Stage II, our last major hydropower project.
The Department of Agriculture needs to popularise SRI method of cultivation of paddy especially for small farmers under minor irrigation schemes, which would save costs and increase farmer incomes.
Control Bata lines
Bata lines throughout the country have escaped examination and inspection by the public and the officials who turned a blind-eye. They are responsible for the massive waste of water and need to be controlled.
Educate farmers and public
Sri Lanka is blessed with plenty of rainfall compared to most other countries in the world. The farmers, cultivation societies and agricultural officials need to be educated on the optimum use of rain water and prudent use of water from irrigation tanks and issue from tanks would be only to rectify shortages.
Usage of valuable water for political reasons such as bathing for pilgrims during Poson should be completely stopped. The public needs to be educated on the value and control of water.
Convert drought into a blessing
If a sincere effort is made, any negative situation could be converted into an asset. A good example is the construction of a hotel by the Kandalama Lake in the early 1980s, which was opposed by Buddhist priests, locals, and the environmentalists. The hotel developers were forced to take corrective action. Today, Kandalama Hotel is recognised throughout the world as an iconic green hotel and sets world standards.
In a similar manner, if politicians along with officials could educate farmers and public in conservation and prudent usage of rain and stored water, there would be sufficient water for all cultivations, full capacity hydropower generation and sufficient water for the implementation of Victoria stage II.
(The writer is a Chartered Civil Engineer who graduated from Peradeniya University and has been employed in Sri Lanka and abroad. He was General Manager of State Engineering Corporation of Sri Lanka and left the position in February 2010. He is presently employed at a Chinese construction organisation. He also ran a manufacturing and a sales organisation for over a decade.)