Drought and lessons learned
The unprecedented drought over the past few months due to the long delay of the south-west monsoon affected the entire country, resulting in withered paddy-fields to farmers; chicken farmers forced to slaughter animals due to water scarcity, soaring vegetable prices for housewives, and power cuts for everyone. The effects of the drought, the victims and their problems were highlighted in the media.
Changing weather patterns
Normally the south-west monsoon should have brought heavy rains to west, south and mountain regions during the May-June period, but failed to appear as expected causing enormous problems to the populace.
The rains made a late appearance in August and are continuing into September. The delayed monsoon brought relief to the south-west, but the rest of the country is still suffering. Typically, the south-west monsoon comes with the winds and as the rains progress, the wind loses its intensity, resulting in a dry period in July-August. After the pause, the wind changes direction and re-appears creating north-east monsoon rains.
The delayed monsoon rains during August/September were welcome but is raising a problem for the north-central and eastern regions, which normally anticipate rains by mid-September. Will the weather Gods make a sudden change in the wind direction to create rains to allow the farmers’ Maha season cultivation or will there be a delay? The current trend suggests sudden changes in wind direction is unlikely and that the Maha rains will be late. It is likely that the populace of the north and east are destined to endure extended period of drought.
Expect floods
In 1957 the country suffered a severe drought, followed by a massive flood which inundated and destroyed most of the central and eastern provinces. This year too, having experienced a prolonged drought, with a delayed south-west monsoon condition, a similar situation is probable. Currently all reservoirs in the central, north and east are empty, farmers expect rains in a couple of weeks to commence Maha cultivation, but will the rains come?
Compared to the situation half a century ago, the country is more structured to handle a continuous downpour due to the construction of massive reservoirs. To achieve maximum benefit, the reservoirs in the North Central and the East need to be kept ready to store the expected rains. Recent rains in the hill country have brought waters into Mahaveli, which have been diverted at Polgolla to feed Anuradhapura farmers, as indicated by the continuing low amount of stored water in the Victoria reservoir.
If diverted Mahaveli waters continue to fill Kalawewa, etc., as previously, when heavy rains arrive, there would be no storage capacity for rainwater and floods and devastation would be inevitable. Alternatively, if the diversion of water is controlled to only supply the basic needs of people (now the cultivation requirement is over) will increase the water in the Victoria Reservoir and increase power generation capacity of Victoria power plant.
Learn from the past
Over the past months, prior to the onslaught of the drought, a number of my articles published in Daily FT highlighted the shortcoming within Government institutions in utilisation of rain and Mahaveli waters and the attitudes of the farmers towards cultivation and their practices.
Finding fault for past happenings does not serve any purpose, but re-examination of what happened is important to learn lessons for the future.
The drought
The CEB was first to be affected by the drought and since June has complained of the shortage of rainfall, reduction of water levels in reservoirs, inability to run hydro-power plants that generate electric power, the forced purchase of expensive power from private power generators and escalating costs.
Farmers in the Anuradhapura district, especially whose paddy fields were fed from Kalawewa complained of a shortage of water since early July, as the Kalawewa waters were diverted to feed Anuradhapura tanks for the pleasure of pilgrims during Poson festival held in early June.
Polonnaruwa had heavy rains up to March and Parakrama Samudraya had reached spill level. Farmers claimed that water was released in advance prior to the commencement of cultivation. Authorities wanted to release water in mid-March, but farmers were not ready for the Yala season cultivation. Yet water was released in early April as some cultivators have sown seed paddy as agreed. Others wished to cultivate after celebrating Sinhala New Year. It was the farmers who cultivated in May who suffered due to water shortage.
In early August, the farmers in Embilipitiya blocked roads and protested that the canal carrying water from Chandrika Wewa was obstructed by a politician, who diverted water to his paddy fields, depriving others and STF had to intervene.
However, the B-Onion, potato and chillie farmers had a bumper crop and protested demanding the raising of duties on imported items, for which the Government agreed. This indicates the growers of subsidiary crops had sufficient rains or water for their cultivation.
During November 2011 to March 2012, the country’s East, North Central and Northern provinces had sufficient rains and the majority of reservoirs were filled to capacity. There is no argument that the country faced an unprecedented drought during the May-June period, the South-West monsoon. But the farmers in the north and the east do not depend on south-west monsoon for their cultivation water. So how did this calamity occur? Let’s get back to basics.
Irrigation in the past
Kalawewa built by King Dhatusena was in existence for over a thousand years, storing rainwater for paddy farmers, so were the other tanks as Parakrama Samudraya. The only major irrigations reservoirs built during the recent era are Senanayake Samudraya in Amparai, Uda Walawa Reservoir in Embilipitiya and reservoirs in Mahaveli for power generation purposes. Traditionally for the Maha cultivation, farmers used rain water, supplemented by tank water during a shortage. Historically, rain water collected in the tanks was reserved for the Yala cultivation.
Mahaveli waters to north
During the mid 1970s, with the construction of the Polgolla Dam, part of the Mahaveli waters were diverted, to fill Kalawewa and Rajangana Wewa, which feed other tanks for irrigation purposes. With the diversion of Mahaveli waters, Kalawewa storage capacity was enhanced and additional paddy lands were opened under the Rajangana Scheme and other minor tanks.
Surplus water from Anuradhapura tanks drained into Malwathu Oya, which had been diverted over a thousand years to feed the Giant’s Tank in Mannar District.
In the planning of Mahaveli project, the priority was for power generation, with a fraction of water to be diverted to supplement Kalawewa, the water requirement of Northern Province was to be achieved by Moragahakanda Project, with the diversion of a tributary of Amban Ganga, a part of Mahaveli River.
But in reality, the bulk of water was diverted to Polgolla, keeping Kalawewa substantially full throughout the year depriving Victoria reservoir which remained practically empty, producing only a small fraction of its generating capability. If the Victoria Reservoir was kept filled instead of Kalawewa, additional power production would have been possible from the same quantity of water due to enhanced water head at the generators.
Warning from the World Bank
During the planning stages of the Mahaveli Development Project in 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 unless this consumption pattern is curbed the entire Mahaveli Project would be a failure.
Studies carried out to ascertain the water requirement of paddy showed rice plants could grow without substantial loss of crop output, even when water is provided once in six days. Agriculturists proposed that water be issued to fields every fourth day and the irrigation water distribution system for paddy fields in Mahaveli System C was designed accordingly. But the farmers prefer to keep paddy fields inundated for weed control purposes, which consumes a huge quantity of water.
Paddy cultivation practices
Paddy farmers at the cultivation committee meeting agree on a cultivation program, 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.
Normally in the East and North-Central Provinces, Maha rains commence around mid- September and prior to the rains the fields are dry and hard, with field bunds damaged due to machinery running over during harvesting and transport. First rains soften the ground and the farmers repair the damaged field bunds, the second and third rains collect water in the fields and ploughing is made possible.
Earlier, farmers used to sweat a lot for cultivation, but now almost every cultivation activity from ploughing to harvesting and packing are mechanised. For the Maha season rain water can be used for land preparation and cultivation days be adjusted accordingly. Therefore it is possible to reduce the usage of water for paddy cultivation without a reduction of output.
What really happened
The CEB is responsible for the generation and supply of electricity to consumers at the lowest possible cost and should have stored water in Victoria, Randenigala and Rantembe reservoirs, but the CEB continued to divert water to Polgolla. Due to the continuous diversion of water over a lengthy period, the farmers and irrigation officials took the diverted water supply for granted, diverting Kalawewa water to Anuradhapura tanks for the Poson season.
The paddy cultivation season in the North commences with the rains in October and harvesting begins in early January continuing to month end. Some rains fall in February and March, but Yala cultivation is mostly based on irrigation water from reservoirs. Sowing of seed paddy is possible from early March (or even mid-February), which would be harvested in June. During the period between harvesting of Maha crop and the Yala cultivation, reservoirs continue to lose water due to evaporation and usage for non-agricultural purposes.
By the end of March, Kalawewa and Parakrama Samudraya were nearing spill and agriculture officials wanted farmers to commence cultivation by mid-March. Only few farmers responded, but water was issued in early April. Others wished to celebrate Sinhala new-year prior to cultivation. It was the paddy fields cultivated in May that got caught to drought in late July. During April for over a month water flowed along the irrigation canals being wasted. It is the same story at Embilipitiya too.
The cultivators of B-Onions, potatoes and chillies had sufficient water, their crops did not get inundated due to unexpected rain and enjoyed a good crop.
The farmers’ crop failure was not due to the drought, but the result of not cultivating in time. Our farmers have been lethargic, and had to pay the penalty for their laziness. None of the politicians had a sufficient back-bone to come out with the truth.
Learn from mistakes
It is clear that the South-Western monsoon was late. But the problems encountered by farmers could have been greatly reduced with proper cultivation practices and intelligent use of water. If we can learn from happenings in the recent past, we could convert the current drought into blessing in disguise. Let us see what could be done.
Cultivate on time
Maha season cultivation can commence immediately after the first rains and the Yala season, immediately after the harvesting of Maha crop. The reduction of time will save water issued from tanks. Early completion of Yala cultivation will allow a third crop, such as maize, chillies or cow-pea which does not require much irrigation water.
Maximum use of rain water
With the current usage of machinery for ploughing and preparation of fields, the requirement of irrigation water and time is lower. By cultivating with the rains, irrigation water requirement for the land preparation can be reduced to a minimum for the Maha season. Tank water should be reserved for Yala cultivation and to cover up shortfalls.
Divert limited waters at Polgolla
As warned by the World Bank, Sri Lankan paddy farmers use the highest quantity of water in the world and during the past decades, usage has increased. We have neglected results of proven field trials conducted decades ago to control wastage of water in paddy cultivation.
Diversion of water to Polgolla needs be limited to original allocation planned to supply needs of System H. This will force everyone to reallocate water issues and conserve.
Produce subsidiary crops
Cultivation of paddy in Mahaveli System H should be only for the farmers so designated when lands were allocated. Others who were allocated land for subsidiary crops as the lands were sandy and unsuitable for paddy cultivation should be encourages returning to subsidiary crops.
Weaning of farmers from paddy to subsidiary crops especially in Yala season, needs to be popularised among the farmers in other irrigation schemes too. With Sri Lanka having reached self-sufficiency in rice, the farmers need to be encouraged to cultivate more subsidiary crops as chillie, potato, onions, mung, soya bean, ground nut and maize which consume less irrigation water, especially on marginal lands.
Hydro-power generation
Due to excessive water diversion, hydro-power generation at Victoria, Randenigala and Rantembe are very much below their full potential. Higher hydro-power production could be achieved by diverting only the originally planned quantity of water at Polgolla and allow balance for power generation.
Victoria Stage II
The country’s bulk of electricity supply comes from thermal power and the hydro-power potential of the country has been nearly exhausted, except for a few minor hydro-power 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 permit construction of Victoria Stage II, our last major hydro-power project.
Educate farmers and public
Sri Lanka is blessed with plenty of rainfall; the farmers, cultivation societies and agricultural officials need to be educated on the optimum use of rain water; sensible use of water from irrigation tanks and issue from tanks would be only limited to rectify shortages.
Usage of valuable water for political reasons such as bathing for pilgrims during Poson should be completely stopped. The farmers and the public who are shocked by the drought would be agreeable for a transformation.
As indicated late Maha rains would be followed by floods; the people need to be pre-warned of the possibility, cultivation needs to be arranged accordingly and the Government agencies should carry out preparatory responsibilities. Above all reservoirs must be made ready for the storage of expected heavy rains. Neglect of so much historical evidence would lead to devastation of the next Maha crop from the flood waters.
(The writer is a Chartered Civil Engineer 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 currently employed with a Chinese construction organisation. He can be contacted on tudor@rivendaleresort.com.)
