David has been appointed as Chief Resident Engineer for the "Mahaweli Water Security Investment Program" (MWSIP). This is an extension of the Mahaweli Development Program (MDP) formulated in the 1960s to create a series of small tank cascade systems in North Central and North Provinces of Sri Lanka taking water from the Mahaweli River Basin using large transfer canals and reservoirs. The updated program is the construction of North Central Province Canal Project (NCPCP) which will be implemented in two sequential phases. Phase 1 comprises three main individual projects, namely Upper Elahera Canal Project, North Western Province Canal Project and Minipe Left Bank Canal Rehabilitation Project.
Upper Elahera Canal Project
The Upper Elahera Canal Project (UECP) comprises two main components. The first component is the 9km Kaluganga-Moragahakanda Transfer Canal (KMTC) which includes about 8km of tunnels - that will convey up to 771 MCM of water annually between Kaluganga and Moragahakanda Reservoirs. The second component is the 61.8 km Upper Elahera Canal (UEC) that will annually convey up to 974 MCM northwards from Margahakanda Reservoir to the existing Huruluwewa Reservoir and a further 17.3 km of canals and 13.3 km of natural streams to supply the existing Eruwewa and Mahakanadarawa Reservoirs. The project is divided into three stages : (a) Stage 1 is the construction of the first 3.8km of UEC's closed conduit canals and associated structures; (b) Stage 2 is the construction of the Kaluganga- Maragahakanda Transfer Canal (KMTC), including a 28km tunnel of the UEC to be constructed by TBM; and (c) Stage 3 which is the UEC level crossings from 6.2 to 17.9km and the remaining 50km of open and cut and cover canal sections, and two tunnels with a combined length of 0.9km.
North Western Province Canal Project
The North Western Province Canal Project (NWPCP) consists of 91km of new and upgraded canals, including four tunnels (Ranediyawa 620m, Niligama 820m, Mahakithula 540m, and Ulpotho 260m) and two new 26m high earth gravity dams impounding the planned Mahakithula and Mahkirula Reservoirs to annually withdraw 130 MCM from Dambulla Oya River and the existing Nalanda Reservoir (via the existing Wemedilla Reservoir) to command new and existing irrigation and water supply reservoirs located throughout North Western Province,