New Delhi, Sep 16 - The government Wednesday gave approval to conduct survey and investigation at the Mullaperiyar dam premises in Kerala to study the environmental effects of building a new dam there.

'It is not a permission to build the dam. This is only to conduct survey and investigation,' said Environment and Forests Minister Jairam Ramesh after the meeting of the standing committee of the National Board for Wild Life here.

The minister said Kerala Chief Minister V.S. Achuthanandan telephoned him Tuesday requesting him to give sanction to conduct survey and investigation.

The Mullaperiyar dam is on the headwaters of the Periyar river in Kerala. According to a 999-year lease agreement signed during the British rule, it is operated by the state of Tamil Nadu.

Citing safety concerns, Kerala has been demanding the construction of a new dam, which is vehemently opposed by Tamil Nadu.