There is a huge difference between dam and barrage, and between how they affect the landscape. A dam is something that’s constructed over a river to control flooding. Barrage is an old method of flood control, where underground pipes were installed to allow water to move freely. Today, there are new inventions for dams, such as Diversion headworks, which divert the water away from the home and onto a safer area.
Diversion headworks and dam are two major types of flood control, but there are many other methods available. A diversion canal can be installed around a home, diverting flood waters away from the house and into a controlled area on land. Another option is having a three gorges dam installed in a river, with a spillway built from ground to top of the gorges to divert the water safely into the safe areas. Having a large lake, containing a natural water flow of over twenty thousand gallons per minute, allows people to benefit from these methods, rather than simply having a dike across the top of the largest dam in the world.
There is no doubt that a large lake allows for more efficient water use, while preventing the runoff from large river into smaller streams or rivers, or even into the ground water. However, having the biggest dam or barrage in the world would also have little effect on the amount of water sent to the water supply, and the impact on wildlife and aquatic habitats would be negligible. The three gorges dam would make a difference, because it could take centuries for water to fill the dam, causing the loss of agricultural and industrial land, and drastically altering the water supply. However, a diversion canal or other type of control would allow for water to be diverted in an effective and sustainable way.