1) Buoyed wreckage 2) City in Russia 3) City in Asia 4) City of Asia 5) City of Russia 6) Ditched cargo 7) European waterway 8) European river 9) European watercourse 10) Goods attached to a buoy 11) Lagend 12) Ligan 13) Overboard goods 14) Relative of flotsam 15) River in Sweden 16) River in Europe Found on https://www.crosswordclues.com/clue/lagan
(from the article `Northern Ireland`) ...hollows. Glaciation also gave the land its main valleys: those of the River Bann (which drains Lough Neagh to the Atlantic Ocean) in the north, ... Found on http://www.britannica.com/eb/a-z/l/6