Nasal congestion Nasal congestion is a stuffy nose, and can be accompanied by blocked ears, sore throat, and more. Pleural effusion Pleural effusion is buildup of fluid in the pleura and can cause difficulty breathing or chest pain.
A hydroelectric dam is essentially a mechanical gateway that can control how often, how much, and how fast the water is allowed to passed through. Water above the dam is collected and stored into a reservoir.
How Dams Work. A typical dam is a wall of solid material built across a river to block the flow of the river thus storing water in the lake that will form upstream of the dam as water continues to flow from the river upstream of the dam.The main purpose of most dams is to create a permanent reservoir of water for use at a later time.s well as being watertight a dam must also be stable ie the dam wall must have sufficient strength to firstly, stand permanently under its own weight especially when at least part of the dam wall is saturated with water and secondly, resist the water pressure in the lake upstream of the dam.