Rivers - Manmade Features

1. Many rivers and canals have locks to make them navigable.

2. Locks allow boats to travel between higher and lower water levels.

3. If the top gate is opened, but the bottom gate is closed, water will pour into the lock.

4. If the top gate is closed and the bottom gate is opened, the water will pour out of the lock into the river.

5. A weir is a dam built across a river or stream to control the flow of the water.

6. A weir is usually built to make a river navigable.

7. By creating a weir, the flow of the water upstream is slowed, and the depth of the water increased.

8. A sluice is a water channel, controlled by gates, used to control the depth and flow of water in a river.

9. Heavy gates are lowered or raised in order to control the water.

10. When the gates are fully lowered, they prevent the water flowing through.

11. If the gates are raised they allow the water to flow underneath.

12. Dams are walls of earth, concrete or rock.

13. Dams are built to retain water, control floods, supply water, improve navigation and provide electric power.

14. An artificial lake, or reservoir, may form behind the dam which can be used for water, or for recreational activities.

15. Some rivers have artificial river banks made of stone, brick or concrete.

16. Embankments allow paths and roads to run right up to the riverside and may also have moorings for boats.

17. Jetties extend out into the water.

18. They are used to direct a current or to provide berthing for ships.

19. Jetties can be made from wood, stone or concrete.

20. Many rivers have docks for boats to load and unload their goods.

21. Docks are are enclosed areas of water used for loading, unloading, building or repairing vessels.

22. At the docks, the riverbanks are built up to form vertical sides for the boats to tie up against.

23. Bollards are often set into the top of the dockside for boats to tie up to.

24. Ladders are fixed to the walls to help sailors climb into their boats.

25. Ports exist at the mouths of many large rivers for ships to dock and unload their cargoes.

26. They often have cargo-handling equipment such as cranes and forklifts that are used to load and unload the ships.

27. Some ports on river estuaries handle ocean-going vessels as well as river traffic.

28. Some of the world’s largest ports are found on estuaries.