- Concerns over preparedness to provide water for drinking, agriculture, and power generation
With the Meteorology Department predicting below-normal rainfall in the coming months, concerns have arisen over the readiness of key State institutions responsible for ensuring uninterrupted drinking water supply, supporting agriculture, and maintaining continuous electricity supply. The effectiveness of these sectors depends heavily on the country’s water reservoirs.
The latest report (SF-2024-02-R) from the Department of Meteorology’s Seasonal Forecasting Division, issued on 31 January, indicates that the current El Niño conditions are expected to persist, with a transition to ENSO-neutral favoured during April-June.As per the report, the positive Indian Ocean Dipole (IOD) is nearing its end and below-normal rainfall is likely in most parts of the country for February-April 2024, except in the Northern and Eastern Provinces.
Further, observations suggest historical impacts of El Niño on monthly rainfall anomalies, indicating below-normal rainfall for most parts of the country in February, March, and April. Meanwhile, the positive IOD has weakened, according to forecasts from the Australian Bureau of Meteorology.
In the backdrop of the scientific reports suggesting below-normal rainfall, which may result in a dry season as predicted, National Water Supply and Drainage Board (NWSDB) Chief Engineer Eng. Ruwan S. Liyanage said: “We have a plan for emergency situations and we will implement that plan, which includes supplying water through water bowsers from available resources.”
In 2017, Sri Lanka experienced one of its worst droughts in over four decades. It hit the northern dry zone especially hard, causing significant reductions in the production of rice, a central pillar of national food security, and affecting 20 districts and approximately 1.8 million people.
The most recent drought in the 2019 Yala season affected over half a million people in 105 DS divisions in 18 districts. One of the hardest hit areas was the Puttalam District. The rainfall for the whole of 2018 had been insufficient for cultivated land in the district. Almost 800 irrigation tanks out of the 1,380 in the Puttalam District had been depleted.
Water management for power generation
Ceylon Electricity Board (CEB) Spokesman Deputy General Manager Noel Priyantha addressed the adjustments in water management for hydropower reservoirs, stating: “Earlier, we have generated hydropower to meet nearly half of the demand, but now we have cut it down and are using other energy resources to generate electricity.” This highlights the shift in energy sources to ensure a balanced approach during the anticipated dry season.
“It is necessary to manage hydro resources carefully as the priority would be to save more water for drinking and agricultural purposes,” he added.
Another senior CEB official, speaking on the grounds of anonymity, told The Sunday Morning: “If required, steps will be taken to procure emergency power to meet any deficit during the dry season.” He emphasised on the organisation’s commitment to guaranteeing an uninterrupted power supply, even in the face of potential challenges during a drought.
For power releases, the decisions include maximising generation at Castlereagh, Maussakele, and Samanalawewa and maintaining specific inflow generation for reservoirs like Udawalawe, Upper Kotmale, Kotmale, Bowatenna, Moragahakanda, Victoria, Randenigala, and Rantembe. Additionally, irrigation diversions have been outlined from various reservoirs to specific downstream locations, with details on the quantity used and percentage of use.
As per the Daily Energy Data report for 14 February, the contribution of the main hydropower reservoirs included Laxapana Hydro Complex (3.52 GWh), Mahaweli Hydro Complex (4.72 GWh), and Samanala Hydro Complex (1.31 GWh).
Thermal sources, specifically coal (19.48 GWh) and oil (3.09 GWh), make up a significant portion, with Independent Power Producers (IPPs) contributing 6.96 GWh through thermal oil. Renewable sources, including wind (1.45 GWh), solar (2.08 GWh), and biomass (0.43 GWh), play a notable role.
The total energy generated on this date is reported as 46.78 GWh. The report emphasises on the inclusion of various power producers and notes that data not available in daily records will be included in annual publications. This information is crucial for stakeholders in making informed decisions for sustainable and reliable energy management.
As of 15 February, the status of reservoirs in the Full Supply Level (FSL) storage system reveals that in the Macro System, reservoirs like Mahaweli GDR (Kotmale), Victoria, Randenigala, and others show robust water levels. Moragahakanda and Kalu Ganga reservoirs have high percentages of active storage. Maduru Oya reservoir stands out with an impressive 99.7% active storage.
National Drought Plan
As per the National Drought Plan of Sri Lanka, the annual total volume of surface and ground water availability has been assessed at 44,000 MCM and 7,800 MCM respectively. In terms of water demand, 87.34% of freshwater withdrawals are used for agricultural purposes and the rest is industrial and municipal water withdrawals. The per capita water availability is about 2,500 m3. Therefore, Sri Lanka can be considered as a country with a sufficient amount of available water.
It is estimated that by 2025, under the current scenario, most of the districts in the dry and intermediate zones of Sri Lanka will face severe seasonal or year-round absolute water scarcity.
About 230 man-made major and medium irrigation reservoirs and about 12,000-15,000 minor irrigation reservoirs/village tanks make up the main component of current irrigation sources, with a total irrigable area of about 745,000 ha.
Sri Lanka now cultivates around one million ha of paddy land, of which around 45% is under major irrigation schemes, 25% under minor irrigation, and 30% rainfed. In the same areas, farmers are engaged in cultivation of other highland food crops such as chilli, onion, vegetables, pulses, tuber crops, maize, and other cereals in small extents that amount to a total of around 150,000 ha.
Farmers in dry zone areas are urging the Government to take necessary steps to save water resources for cultivation.
K. Siripala, a 72-year-old farmer from Udawala, stressed that when the authorities failed to take required actions, it was the farmers who ultimately suffered.
“I have decades of experience; even though they say they will take care of our farm lands, there’s nothing left to do when there is no water in reservoirs. We experienced that even last year. Therefore, we beg them to start working on the required projects from now on without waiting till the last moment.”