Water highways are cheaper than road and rail to develop and maintain. The cargo conveyance cost, too, is lower because of minimal energy requirements. One horsepower of energy can ferry four tonnes by water, against only 150 kg by road and 500 kg by rail. Many countries in Europe and elsewhere carry over 40 per cent of their passenger and freight traffic through water. But in India this proportion is only 3.5 per cent. However, to be operational year-round and able to carry heavy loads, India's water channels will need to have adequate width, depth and air clearance. Many rivers are seasonal, with water flows declining sharply after the monsoon. Navigating such rivers in the lean season may, therefore, require regular and extensive dredging and desilting. Moreover, water highways will require more river ports with their support infrastructure - road and rail connections, warehouses and other services. Heavy investment will be needed also to procure equipment, including dredgers, shipping vessels and barges of different sizes.
The government has indicated that it will explore multiple sources of finance, including market borrowings and tapping the National Clean Energy Fund and the Central Roads Fund. Private participation in infrastructure is needed - but will be possible only if such ventures become economically viable. For this, they will require adequate and assured two-way traffic. But the traffic in bulk goods, such as coal, minerals, foodgrain, fertiliser and similar other commodities is often unidirectional, compelling the vessels to return empty or under-loaded. This aspect will need to be weighed and addressed.