Leaky Bangkok train tunnel slowly being plugged

PUBLISHED : 12 Jul 2026 at 11:21

Repairs to the leaky Purple Line train tunnel in Klong San district, Bangkok, were making progress and the water flow has already been reduced, the city governor said on Sunday morning.

Chadchart Sittipunt was speaking at the site of the leak, near Wong Wian Yai roundabout. He said five grouting machines were being used to strengthen the soil adjacent to the tunnel.

Tunnel grouting machines are specialized systems used to inject grout into the gap between pre-cast concrete segments and the surrounding ground.

Mr Chadchart said cement grouting had reduced water leakage into the tunnel from 50 cubic metres per hour to 20 cubic metres an hour as of Saturday evening.

“The present situation is free of concern,” he said.

Mr Chadchat said there should not be any further obstacles to the repair work. Rainfall was limited on Saturday. He was informed on Sunday morning there had been no further subsidence of nearby buildings or road surfaces.

Authorities had ordered the evacuation of two apartment buildings, and 111 residents agreed to move out. Seven residents had refused to leave the affected buildings, he said.

The water leak started in one of the two tunnels in the extended section of the Purple Line railway system on Wednesday. The extended section was the site of a huge sinkhole on Sam Sen Road in Dusit district last year.

The present leak was spotted at a sump pit in the tunnel. It caused the subsidence of about 30 centimetres of the surface of Prachadhipok Road, and big cracks appeared in some nearby buildings.