Explanation:

Allahabad-Haldia stretch of the Ganga—Bhagirathi-Hooghly Rivers            
NW2    Sadiya-Dhubri Stretch of Brahmaputra River            
NW3    Kollam-Kozhikode Stretch of West Coast Canal and Champakara and Udyogmandal Canals            
NW4    Kakinada-Puducherry Stretch of Canals and the Kaluvelly Tank, Nashik-Bhadrachalam-Rajahmundry Stretch of River Godavari and Bridge near village Galagali-Wazirabad-Vijayawada Stretch of River Krishna            
NW5    Talcher-Dhamra Stretch of Brahmani-Kharsua-Tantighai-Pandua Nala-Dudhei Nala-Kani Dhamra-river system, Geonkhali-Charbatia Stretch of East Coast Canal,harbatia-Dhamra Stretch of Matai River and Mahanadi Delta Rivers
NW6      Lakhipur Bahnga stretch on Barak river in Assam
The National Wateryways Bill was passed last year to declare 106 new national waterways. Declaring a waterway as national waterway allows centre government to develop and maintain it.
Inland Waterways offer following advantages over land based transport systems
•    They can carry bulkier goods that otherwise cannot be carried on roads or rails.
•    They are about twice more efficient than roads and railways in terms of per kilometer cost of transportation.
•    Being able to move more load in lesser fuel inland waterways offer an environment friendly mode of transport.
Disadvantages
•    The seasonal nature of several rivers
•    Problem of last mile connectivity often leads to increased costs due to frequent loading and unloading