Kalu Ganga Water Treatment Plant, Horana Sri Lanka

Project Features

Major expansion of water supply to service the southern areas of Greater Colombo; construction of 126 000 m3/d run-of-the-river intake on the Kalu Ganga, low-level intake pump station with a capacity of 2,628 m3/h, 200 m of 1,000 mm diameter raw water main pipeline, 60 000 m3/d water treatment plant and clear water-high level pump station, 6 km of 1,000 mm diameter clear water transmission pipeline, 15,000 m3 clear water reservoir, 20 km transmission pipelines with diameter up to 1,200 mm, metered connections and associated facilities; procurement of equipment and vehicles for operation and maintenance.

Scope of Services by Purac

Procurement and supply of mechanical and electrical equipment including the SCADA system for raw water intake pumping station, Water Treatment Plant and High lift pumping station.
• Installation supervision.
• Assistance in commissioning.
• Operation and maintenance of completed facilities.
• Training of relevant staff.

The process comprises the following stages
of treatment;

Flocculation with Alum – Sedimentation – Filtration – Conditioning, (pH & Cl2 ), and produce drinking water to Sri Lankan Standards. The WTP is equipped with a laboratory for continuous auto and manual quality monitoring. Puracs role of the project was as a sub-contractor to China Geo Engineering Coorporation. The project was financed as a soft loan by Japan Bank for International Cooperation. The Project was finalised and handed over to the end-user National Water Supply and Drainage Board in 2007.


Technical data

Intake capacity: 126 000 m3/day 

200 m raw water pipeline

6 km clear water pipeline

20 km transmission pipeline