The Chalakudy River Diversion Scheme envisages to irrigate a total ayacut of 14142 Ha. of land as a part of Parambikulam Aliyar project, the water from Kerala Sholayar stores in Poringalkuthu Reservoir and the tail race water after generation reaches to the Thumburmuzhy weir and distributing through Right Bank Canal and Left Bank Canal system.  This scheme had its first stage completed in 1957 and the second stage in 1966.  The head works of the Project is at Thumboormuzhy which comprises of a gravity type weir having 185 m length in with course rubble masonry casing with concrete across the Chalakudy river.  Originally the maximum height of the weir was 3.66 m.  This was increased by 0.30m with concrete casing as part of the developmental works when the Chalakudy Project was made an integral part of the Idamalayar Irrigation Project.

The canal system of the project consists of two main canals viz. the Right Bank Main Canal and the Left Bank Main Canal with their branches and distributories.  The Right Bank Main Canal has a length of 48,200 km and that of the Left Bank Main Canal is 33.2 km.  The total length of branches and distributories comes to 297.8 km.