All Lanes Closed on Pracha Thipat Road Over Transit Tunnel Leak
All lanes on Pracha Thipat Road are closed due to water seeping into an underground tunnel being built for the Purple Line extension near a major roundabout. Pumping operations are managing the leak, with water inflow decreasing as repairs
All traffic lanes have been closed from Ban Khak intersection to Pracha Thipat Road and the large roundabout due to water seepage in the underground tunnel under construction for the Purple Line extension. Emergency pumping operations continue to manage water accumulating in the sump basin beneath the tunnel near the major roundabout. Prime Minister Anuthim Chanyaweerakul and his team inspected the site last night, assessing that water levels remain within manageable limits. Officials were ordered to accelerate repairs to prevent impacts on public safety.
On July 9, reporters visiting the area found that Mass Transit Authority (MTA) staff and engineers remained on-site conducting close monitoring throughout the morning. MTA Board Chairman Montri Dethasakulsomm stated that preliminary assessment indicates the leak originates from a defect in the sump basin or water collection pit. Authorities immediately began repairs, focusing on preventing additional water inflow while continuously pumping water out. The pumping system currently handles incoming water flow, which decreased from approximately 70 cubic meters per hour overnight to about 50 cubic meters per hour by morning, indicating improving conditions.
Montri clarified this incident differs from the Samsen area case, resulting from a construction defect that MTA has ordered contractors to repair urgently. To prepare for heavy rainfall, MTA has ordered installation of additional underground dewatering systems, including deep wells approximately 50 meters deep to extract groundwater and reduce sump basin inflow. Grout injection to seal leaks is complete, and construction of underground curtain walls continues to prevent groundwater infiltration and reduce surrounding area impacts.
Latest inspections found no additional structural settlement, tilting, or new cracks, with nearby elevated structures remaining normal. MTA has ordered contractors to conduct detailed building inspections in the area with district engineers to ensure public confidence. The dewatering system begins today with pumping expected to start tomorrow, while curtain wall construction should complete within approximately one week. The surrounding area remains stable with no additional subsidence detected.
The rail line project is scheduled for completion in late 2027. Overall conditions are not concerning, as MTA and contractors are addressing issues promptly with 24-hour monitoring in accordance with government and transport ministry policy to ensure safe construction and public confidence. Traffic management initially will close the two leftmost lanes on Pracha Thipat Road outbound.
