The country’s major reservoirs are showing worrying variations in water storage, with several tanks recording critically low effective storage levels amid continuing concerns over water availability.According to the Irrigation Department’s latest reservoir data for August 23, the 74 major reservoirs covered in the report hold only 35.8% of their effective storage capacity.The situation is particularly concerning in several areas. Manankattiya Reservoir in Anuradhapura has just 1.5% effective storage, while Muruthawela in Hambantota stands at 1.6% and Ethimale in Monaragala at 5.4%. Rottikulama in Ampara is also at only 8.1%.

At the same time, some reservoirs remain relatively well supplied. Deduru Oya is at 94.6%, while Wan Ela is at 96.9%, Vakaneri is at 96.2%, and Rajangana is at 85.5% effective storage.Despite the sharp differences between reservoirs, the Irrigation Department report records no spilling at any of the listed reservoirs.The figures raise questions over how effectively available water resources are being managed, particularly in districts where storage has fallen to extremely low levels. With the overall effective storage of the 74 major reservoirs at just over one-third, authorities could face increasing pressure if dry conditions persist.The latest figures were issued by the Irrigation Department’s Water Management Branch on August 23, 2026.