The Calcutta Municipal corporation will not issue any more licences for sinking deep tubewells in housing complexes. The reason: a sharp fall in the city's ground water level. A circular to this effect will be issued by the Municipal Commissioner, Mr Asim Barman, soon. The decision is based on a status report on ground water level prepared by the CMDA's environment cell. The Calcutta Metropolitan Development Authority has asked the civic authorities to stop the use of ground water.