Calcutta, June 12 :     Disgusted over frequent power fluctuations causing a chronic disruption in water supply, residents of Topsia got hold of a CESC employee on Thursday and threatened to hold him hostage till they were provided with adequate drinking water. Taps have run dry at about 4,000 homes in the area because of frequent tripping of power that drives their deep tubewells. The areas hardest hit are Topsia Second Lane, Topsia First Lane and Topsia Road. When another trip in power sparked a fresh 'dry spell' on Thursday, tankers had to be requisitioned from the CMC's water supply department. Residents complained that despite repeated requests, the CESC was not attending to the fault. Supporters of local councillor Javed Ahmed Khan called in a CESC worker attending to a cable fault in a factory in the area. When he expressed his inability to attend to their problem without a specific work order, angry residents threatened to hold him hostage. Javed Khan alleged that the CMC and the CESC were in collusion to disrupt water supply to the area, ahead of the municipal elections. As Topsia was added on to the Calcutta Municipal Corporation later, the area does not have a direct link with the Tallah-Palta network. So, deep tubewells are the mainstay for water in this ward. It was expected that with the commissioning of Park Circus booster pumping station, the situation would improve. Javed Khan said Trinamul Congress leader Mamata Banerjee had assured him of funds for water mains in the Topsia area. Besides low pressure, severe contamination is another hazard. In a number of places, the water lines have passed directly through sewer lines. Which is why, health oficials said, the Topsia belt tops the city in the incidence of diarrhoea. Diarrhoea is so acute here that the councillor has to arrange a mobile medical van from his own pocket to attend to patients.