Sri Lanka has achieved a major engineering milestone with the successful completion of excavation work on what is set to become South Asia’s longest irrigation tunnel, officials announced.
The 27.7-kilometre tunnel, built under the North Central Province Canal Project, forms a key part of the Mahaweli Master Plan and was completed following a significant underground breakthrough involving two advanced Tunnel Boring Machines (TBMs).
Excavation began simultaneously from Maha Meegaswewa and Koduruwawa, with the project reaching its “Tunnel Breakthrough” when the two tunnel sections successfully met beneath the ground.
The tunnel is being developed under the Mahaweli Water Security Investment Programme, with financial assistance from the Asian Development Bank (ADB), and is expected to be the longest irrigation tunnel in South Asia.
The North Central Province Canal Project, which extends nearly 240 kilometres, aims to strengthen water distribution across the region by supplying water to 1,505 reservoirs connected through 12 major irrigation systems and 130 cascade networks.
According to authorities, the project will directly benefit around 25,000 families while supporting agricultural activities across 74,000 hectares of farmland during both the Yala and Maha cultivation seasons.
The initiative is also expected to improve access to safe drinking water in the Rajarata region, where communities have long been affected by chronic kidney disease of unknown origin (CKDu).
Once fully operational, the project is expected to release approximately 70 million cubic metres of water annually, helping meet the drinking water needs of nearly 1.5 million people while strengthening water security and agricultural productivity in the region.
