A dam is a pressure driven structure of genuinely impenetrable material worked over a river to make a reservoir on its upstream side for seizing water for different purposes. These reasons might be Irrigation, Hydropower, Water-flexibly, Flood Control, Navigation, Fishing and Recreation.
Dams might be worked to meet the one of the above purposes or they might be built satisfying multiple needs. Accordingly, a dam can be delegated as Single-reason and Multipurpose Dam.
Dams can be characterized in a number of ways. In any case, most regular ways of order of dams are referenced underneath. In view of the elements of the dam, it very well may be named as follows.
They are developed to store water during the blustery season when there is a huge stream in the river. Numerous little dams appropriate the spring spillover for later use in dry summers. Storage dams may likewise give water flexibly, or improved living space for fish and natural life.
They may store water for hydroelectric force age, water system or for a flood control venture. Storage dams are the most widely recognized kind of dams and when all is said in done the dam implies a storage dam except if qualified something else.
A diversion dam is built to occupy water of the river into an off-taking trench (or a channel). They give adequate strain to driving water into trench, waterways, or other transport frameworks. Such shorter dams are utilized for the water system, and for diversion from a stream to an inaccessible storage reservoir.
A diversion dam is for the most part of low tallness and has a little storage reservoir on its upstream. The diversion dam is such a storage weir which likewise redirects water and has a little storage. Once in a while, the terms weirs and diversion dams are utilized interchangeably.
Detention dams are built for flood control. A detention dam impedes the stream in the river on its downstream during floods by putting away some rising water. Therefore the impact of abrupt floods is diminished somewhat.
The water held in the reservoir is later discharged progressively at a controlled rate as indicated by the conveying limit of the channel downstream of the detention dam. Therefore the territory downstream of the dam is secured against flood.
A debris dam is developed to hold debris, for example, sand, rock, and flotsam streaming in the river with water. The water subsequent to disregarding a debris dam is generally clear.
It is a fenced area developed around the building site to reject water with the goal that the development should be possible in dry. A cofferdam is in this way a transitory dam developed for encouraging development.
A coffer dam is normally developed on the upstream of the principal dam to occupy water into a diversion tunnel (or channel) during the development of the dam. At the point when the stream in the river during development of the dam isn't a lot, the site is normally encased by the coffer dam and siphoned dry. Once in a while a coffer dam on the downstream of the dam is additionally required.
A gravity dam is a huge estimated dam created from concrete or stone brick work. They are intended to keep down huge volumes of water. By utilizing concrete, the heaviness of the dam is really ready to oppose the even push of water pushing against it. This is the reason it is known as a gravity dam. Gravity basically holds the dam to the cold earth, preventing water from bringing it down.
Gravity dams are appropriate for blocking rivers in wide valleys or restricted chasm ways. Since gravity dams must depend on their own load to keep down water, it is important that they are based on a strong establishment of bedrock.
An earth dam is made of earth (or soil) developed by compacting progressive layers of earth, utilizing the most impenetrable materials to shape a center and setting increasingly porous substances on the upstream and downstream sides.
An installment of crushed stone forestalls disintegration by wind or downpour, and a sufficient spillway, as a rule of cement, secures against calamitous waste of time should the water overtop the dam. Earth dam opposes the powers applied upon it for the most part because of shear quality of the soil. In spite of the fact that the heaviness of the earth dam likewise helps in opposing the powers, the basic conduct of an earth dam is altogether not the same as that of a gravity dam.
A rockfill dam is made of rock sections and stones of huge size. An impenetrable layer is set on the rockfill on the upstream side to diminish the drainage through the dam. The film is normally made of concrete or asphaltic cement. In early rockfill dams, steel and wood layers were additionally utilized, however now they are out of date.