Cauvery Delta

Nagapattinam has the longest coastline in the state of Tamil Nadu and is at the tail end of the Cauvery delta which covers an area of 16 lakh acres. 12 lakh acres are spread across Thanjavur, Thiruvarur and Nagapattinam and the remaining 4 lakh acres, across Pudukottai, Cuddalore and Karaikal (Union Territory of Pondicherry).

There are 14 river systems subdivided into 1141 irrigation canals of 1324 km length, and 180 drainage canals of 346 km length in Nagapattinam. 6 out of 11 administrative blocks have saline groundwater and 5 blocks have already overexploited their groundwater resources.

Criss-crossed by rivers and canals, and beset alternately by droughts and floods, this district is especially vulnerable because two thirds of the district consists of low lying lands. River systems are poorly maintained and the coast is flat without any gradient that results in no base flow during the dry months – February to July. This also causes sea water ingress into the coastal plain.