Two months after the opening of a section of Mumbai's Coastal Road tunnel to traffic on March 11, observations have been made of water leaks. It has been noted that water is seeping through the walls and ceiling, particularly at the southbound tunnel's end near Princess Street Flyover. Despite repairs made during testing, this issue continues.

Leaks have been sighted on both sides of the walls in the southbound tunnel, with the slab above also appearing wet. The ongoing water leakage has resulted in the paint on the walls peeling off. The BMC is under scrutiny as it prepares to open another tunnel soon. The adjacent northbound tunnel, which is still under construction, is anticipated to open in June. The persistent leaks, initially identified during testing and supposedly fixed, have reappeared within two months of the tunnel's opening.

A senior official involved in the Coastal Road project mentioned, We are dealing with expansion joints located every 20-30 meters, not cracks. These joints allow for contraction and expansion, causing the leakage. We will immediately address the leaks by employing injection waterproofing and grouting to seal them. This issue typically arises during construction or due to equipment usage, but once resolved, further leakage should not occur. The water has dispersed, leading to the loss of colour.

The Coastal Road tunnel is notable for being India's first constructed using tunnel boring technology. The entire coastal road from Mumbai to Kandivali spans 29 km, with the completed phase in South Mumbai covering 10.58 km. The project has incurred an approximate cost of Rs 127.21 billion.