Union Road Transport and Highways and Shipping Minister Nitin Gadkari on Friday said the work for Sagar port project will start before December this year."We will start the work of Sagar port project before December. The Sagar port will be an addition to the 12 major ports of the country. The investment would be around Rs 4,000 crore for the port and road-cum-railways overbridge," said Gadkari.The technical and feasibility study for the project has already been completed."We have formed a joint venture company with the West Bengal government for the development of the port," he said.The minister said the draft could not be increased over 14.5 metre for both the Kolkata and Haldia ports in order to improve the navigability.The Centre is planning to develop the two ports for cargo transportation between Bangladesh and India."About 6,000 million tonnes of cargo is being transported between Bangladesh and India for export-import purposes. 95 per cent of it is transported through roads. We want entire cargo should go through waterways to reduce the logistic costs," Gadkari said."We have talked to Bangladesh Foreign Minister regarding this," he said. The Centre is working on development of 1,620 km waterways on the river Ganges from Varanasi to Haldia, he said.