Saraswati River refers to a river, that was a distributary of the Bhagirathi and is now no more there but was active till around the 16th century AD. The course and condition of the Saraswati has played an important role in the development and decline of river port towns in Bengal. Initially, the major port town was Tamralipta, after the decline of which Saptagram rose and declined, and finally Kolkata came up.
Earlier courseAt Tribeni near Bandel in Hooghly District in the Indian state of West Bengal the Bhagirathi branched off into three streams The Saraswati flowed south-west beyond Saptagram, the Yamuna (this is distinct from the river of same name in northern India and several streams of the same name in eastern Bengal) flowed south-east, and the Bhagirathi proper flowing through the present Hooghly channel to Kolkata and then through Adi Ganga, past Kalighat, to the sea. It is believed that the Saraswati flowed into an estuary near present-day Tamluk and received the waters of not only the Rupnarayan and Damodar but several other smaller streams. Some time after the 8th century AD, Tamralipta lost its importance primarily on account of silting up of the mouth of Saraswati and the consequent shifting of its course.
The Saraswati moved to a position when it flowed out at Triveni and after a movement towards the west turned to the southeast to meet the Hooghly River again at Betore opposite present Garden Reach, thus forming a loop. Saptagram was situated on the upper part of the loop on the southern bank. It is believed that the Saraswati had an independent course to the sea.