AIADMK general secretary Jayalalithaa on Monday urged Chief Minister M. Karunanidhi to take steps to prevent the Andhra Pradesh government from going ahead with its plans to construct 10 checkdams across the Ponnaiyaru. In a statement here Ms Jayalalithaa said the Ponnaiyaru was the source of drinking water for Vellore, Kancheepuram, Thiruvallur and Thiruvannamalai districts and construction of check dams would deprive these districts of their drinking water supply. The Ponnaiyaru originates in Srisailam in Andhra Pradesh and confluences with the Palar in Thiruvalam near Vellore. Ms Jayalalithaa said in the past she had successfully foiled the Andhra Pradesh government's attempt to construct dams across the river in Gangadharanallur and T Agraharam. Now once again the State government there is planning to construct dams keeping an eye on the polls to the State Assembly, likely to be held by the end of this year or in the beginning of the next year, she alleged. Ms Jayalalithaa said the Andhra Pradesh Government, like the Karnataka Government, was taking advantage of the DMK being in power and planning to construct dams. "Uncertainty prevails over the Hogenakkal drinking water project since Chief Minister Karunanidhi put on hold the project and issued a statement supporting the Congress government. Is Mr Karunanidhi going to wait till the Assembly elections in Andhra Pradesh are over? Is he going to issue a statement supporting the Congress there also,' she asked. Recalling the efforts taken by the AIADMK government led by her to prevent the dam across the Palar near Kuppam, Ms Jayalalithaa wanted to know why the Chief Minister was refusing to put pressure on the Congress that was in power at the Centre and in Andhra Pradesh. "Let him use his influence at the Centre and stall the construction of check dams across the Ponnaiyaru,' she said.