The government's decision was based on the report of river bank mapping and sand river auditing conducted as per rules stipulated in the Kerala River Bank Protection and Regulation of Removal of Sand Rules.
Sand mining has been banned in Neyyar, Vamanapuram, Kallada, Kuttiyadi, Kabani and Chandragiri rivers, as according to the sand auditing report, "total quantity of sand above the summer water level in these rivers is estimated as nil."
The sand river auditing report, conducted by different agencies, was compiled by the Departments of Environmental Sciences, Aquatic Biology and Fisheries and University of Kerala, an official release said here.
Extraction of sand would be allowed only in a phased manner and mineable sand quantity would be revised based on a subsequent sand audit, the release said.