Muthupet Lagoon is located at the southern end of the Cauvery river delta on the Bay of Bengal, covering an area of approximately 6,803.01 ha of which only 4% is occupied by well-grown mangroves.
The rivers Pamaniyar, Koraiyar, Kilaithankiyar, Marakkakoraiyar and other tributaries of the Cauvery flow through the area and adjacent villages.
The northern and western borders of the lagoon are occupied by muddy, silty ground, which is devoid of mangroves.
The word 'lagoon' refers to the shallow salt or brackish water body that lies close to the sea.
There is a difference between the lagoon shore and seashore of the same mudflat, in the aspect of distance of mangroves from fluctuating water level.
But, the remaining barren ground is hard (clay) which may due to the erosion of surface silt by wind or floodwater.
Thousands of partially decomposed rooted trunks that found on the southeastern side of Muthupet lagoon are indicating the past, indiscriminate exploitation.