navigability n : suitability for the passage of a ship or aircraft
- the state of being navigable
- French: navigabilité
A body of water, such as a river, canal or lake, is navigable if it is deep, wide and slow enough for a vessel to pass and there are no obstructions, like rocks, trees and low bridges. Shallow rivers may be made navigable by the installation of locks that increase and regulate water depth, or by dredging. A very high water speed may also make a channel unnavigable and high-latitude waters may be unnavigable in winter because of freezing. Navigability also depends on the size of the vessel: A small river may not be navigable by a freighter, but it might be navigable by a smaller craft, like a motor boat or kayak. Therefore, whether a water body is considered navigable or unnavigable depends on the context.
In addition, navigable waters of the United States, as defined in 33 CFR 329, are those waters that are subject to the ebb and flow of the tide and/or are presently used, or have been used in the past, or may be susceptible for use to transport interstate or foreign commerce. Section 10 of the Rivers and Harbors Act of 1899 (33 U.S.C. 403), approved March 3, 1899, prohibits the unauthorized obstruction of a navigable water of the U.S. This statute also requires a permit from the U.S. Army Corps of Engineers for any construction in or over any navigable water, or the excavation or discharge of material into such water, or the accomplishment of any other work affecting the course, location, condition, or capacity of such waters.
Also, the Clean Water Act use the term "navigable waters," "navigable waters of the United States" and "navigablity." These terms are dependent on judicial interpretation and are somewhat more flexible currently, in light of a U.S. Supreme Court decision on two joined cases: "Carabell v. United States" and "Rapanos vs. United States".
Inland Water Transport SystemsInland Water Transport (IWT) Systems have been used since prehistoric times in developed countries like India, China and Egypt.
In modern times, Netherlands, USA, Germany, China, Bangladesh and India IWT has developed a lot and is of much importance. For example, in Netherlands, IWT handles 46% of the nation's inland freight; in Bangladesh it's 32%, in USA it's 14% and in China its 9%.
Inland Water Transport System in India In India there are currently 3 National Waterways totaling a distance of 2921 km. They are
- Haldia-Allahabad stretch of the Ganga-Bhagirathi Hooghly river system (1620 km) in October 1986 as National Waterway 1
- Saidiya Dhubri stretch of the Brahmaputra river system (891 km) in September, 1988 as National Waterway 2
- Kollam-Kottapuram (in Kerela) stretch of West Coast Canal (410 km) along with Champakara canal and Udyogmandal canal in February, 1993 as National Waterway 3
Apart from this there is a huge length of inland waterway of India which is being navigated. In India, it is estimated that the total navigable length of inland waterways is 14500 km. A total of 16 million tonnes of freight is moved by this mode of transport.
Advantages of Inland Water Transport Systems
Waterways provides enormous advantages as a mode of transport as compared to other land or air modes of transports.
- Cheaper Capital Cost - Nature has already done the initial engineering work for the transportation infrastructure. Thanks to this gift of nature, the cost of developing an inland waterway is 5-10% of the cost developing an equivalent railway or a 4-lane expressway.
- Cheaper Maintenance Cost - The maintenance cost of an inland waterway is only 20% of the maintenance cost of an equivalent roadway.
- Greater Fuel Efficiency (Low cost of transportation) - It is estimated that 1 liter of fuel can move 105 ton-km by inland water transport. Whereas the same amount of fuel can move only 85 ton-km by rail and 24 ton-km by road. By air, its even less.
- Easy integration with Sea transport - Inland water transport can easily integrated with Sea transport and hence it reduces the extra cost required for land-sea or air-sea transport interface infrastructure development. It also reduces the time taken to transfer the goods to-n-from sea transport vessels.
Disadvantages of Inland Water Transport Systems
- Low availability of Inland Waterways - As mentioned above, there are numerous criteria for a water body to be navigable. Out of the total inland water body available in the world, only very low percent of it is potentially navigable.
- Low speed - Water transport as a whole is much slower than its road, rail, or air competitors.
navigability in Czech: Splavnost
navigability in Japanese: 航行可能
navigability in Russian: Судоходность