The National Water Supply and Drainage Board (NWSDB) has temporarily suspended the water supply to several areas of the Colombo and Gampaha districts after an urgent problem with water quality was detected near the Kelani River intake point.
Production has been halted at both the Ambatale and Kelani South water treatment plants, Ada Derana reported early on Tuesday. The Board said the suspension followed a notification it received from the Disaster Management Centre (DMC).
The NWSDB said further updates would be issued on when supply would be restored, and apologised to consumers for the disruption.
Why the DMC route matters
The two plants named are central to the capital’s supply. Ambatale is the largest treatment facility serving Colombo and its suburbs, drawing raw water directly from the Kelani River; Kelani South serves areas on the southern bank. A shutdown of both at once removes a substantial share of the metropolitan supply rather than a single distribution zone.
The involvement of the Disaster Management Centre is the notable detail. Routine interruptions — main breaks, scheduled maintenance, pump failures — are announced by the Water Board alone, as when a burst Ambatale–Kolonnawa main cut supply to Colombo suburbs in June. A DMC notification points instead to an external event affecting the river itself.
What has not been said
Ada Derana’s report did not specify which areas are affected, what the water quality problem is or what caused it, or how long the suspension is expected to last. The NWSDB has not published a restoration estimate.
The suspension comes as the Kelani basin runs through a prolonged dry spell, with river flows down across the island and reservoir storage at about 36%. Lower flows in the lower Kelani raise the risk of salinity intrusion at the intake, though no outlet has linked Tuesday’s suspension to that.
As of 6.00 a.m. on Tuesday, no other verified Sri Lankan newsroom had published its own report of the suspension.
