While the new underground tunnel in Andheri has increased water supply by over 30 million litres a day in Andheri West and Jogeshwari West,residents of South Mumbai will have to wait at least a couple of months more to derive the same benefit. Work on the four-kilometre long underground water tunnel from Malabar Hill to Cross Maidan is 90 per cent complete since three months,but the complication in shifting a high tension power cable is causing delay in the last phase. The Rs 150-crore water tunnel,work on which was undertaken in 2007,is to significantly improve water supply in Kalbadevi and Boribunder areas among other ends at Cross Maidan,where a 70-year-old high tension BEST cable runs parallel to it. Additional Municipal Commissioner Rajeev Jalota said after repeated meetings with Brihanmumbai Electric Supply and Transport (BEST) undertaking officials and General Manager O P Gupta,BEST has finally agreed to take up the task of diverting the cables so that BMC can connect the end point of the tunnel to the existing supply pipelines. An official from the BMCs water supply projects department said diverting high tension cables is an uphill and challenging task. The electricity supply of the entire Fort and Churchgate area depends on this cable and it has to be handled with technical expertise. Moreover,it has such high voltage that it poses a risk to human life while being worked upon, he said. Once BEST completes the work,the BMC will need three more weeks to finish the work of connecting pipelines. The open pit at Veer Nariman road has been barricaded for the past four months. Tansa pipelines,which were built by the British,supply water to major parts of western suburbs and island city. The wear and tear of these steel pipelines has caused them to burst a number of times in the past leading to loss of huge quantities of water and subsequent water cuts. The BMC has therefore undertaken work on three major tunnels as a replacement of these pipelines.