Network length is 1,779 km, of this 1,075 km consists of the Danube international waterway, 524 km, navigable branches of the Danube River, and 92 km, channels of the Danube - Black Sea and Poarta Alba (White Gate) -Midia Navodari. Romanian ports have some 49 km for berthing facilities and hydrotechnical constructions, of which 18.1 per cent are more than 50 years old and require urgent reconstruction work. Trends for the transport of goods by inland waterways in Romania show a sharp decline after 1990, from 12 million tons in 1990 to 6 million tons in 1992 and some recovery after 1996, with an average of approximately 14 million tons/year. In 2011, on the Romanian stretch of the Danube River, there were six events involving accidental pollution from ships.