Mumbai: BMC to repair century-old Tansa water pipeline at Lower Parel
Brihanmumbai Municipal Corporation (BMC) has undertaken the mammoth task of repairing leakage in a century-old 1450 mm-wide water pipeline at Gawde Chowk on Senapati Bapat Road in south Mumbai that runs approximately 100 kilometers to bring water to the island city, straight from the Tansa dam in Thane district. The most challenging aspect of repairing the leak is that this water main is buried over 25 to 30 feet under the ground, with a British era storm water drain, a sewage line, and TATA Power’s high voltage power line running right above it, in the middle of a busy street in Lower Parel.
The leak in this Tansa main was detected 10 days ago on November 18, after which staff from BMC’s hydraulics department began excavation work around the area. After excavating up to 30 feet, the team spotted the leak on the underside of the pipeline. It was temporarily repaired by driving a wooden wedge and a patch screw jack under it, without shutting water supply through the pipeline to the surrounding areas.
“It is not possible to dig any deeper as we have already hit hard rock at approximately 30 feet exactly below the leakage point,” a senior civic officer of the hydraulics department said. Now, permanent repairs to the pipeline will now be undertaken on December 2 and 3, and water supply to parts of Elphinstone Road, Prabhadevi, Dadar, and Mahim will be affected partially during this time.
Jeevan Patil, assistant engineer of the water works department (emergency repair cell, Worli) said, “This work is challenging as it needs to be carried out underground. Over the past ten days, we carried out plan A to immediately plug leakage, but beyond a point, it is not possible to fix the pipeline with this method. Now, we are moving to plan B to work inside the pipeline. So far, all the work has been done without damaging any other parallel line such as the sewage line, the storm water drains, or the Tata Power high-voltage live line.”
As part of plan B, BMC has now dug two 24-inch manholes on top of the pipeline, at a depth of 15 feet. While submersible pumps will be ascended through one manhole to draw out the water from the pipeline, the hydraulics team will use the other manhole to access the pipeline and repair it.
A BMC press release said on Monday, “The main valve on the aqueduct [pipeline] will be closed after 8am on December 2, after which both manholes will be cut and the water in the aqueduct will be completely drained. A full inspection will then be carried out inside the aqueduct. The repair work will be started by estimating the extent of damage to the aqueduct due to the leak and the number of leaks. The work is planned to be completed by 3pm on December 3.”