The National Waterway 1 or NW -1 connects Haldia to Allahabad. It is also known as Ganga-Bhagirathi-Hooghly river system. It is 1,620km long and the longest waterway in India. It is of prime importance amongst all the national waterways considering its locational advantages. The NW-1 crosses through West Bengal, Jharkhand. Bihar and Uttar Pradesh.