Explains the classification of dams in detail

Classification of dams is as follows as per their purposes, material, etc.

Classification of dams based on their function:

• storage dams: the main purpose of this dam is to store rainwater during the rainy season when there is a large flow coming from the river. This is the most common type of a dam we always say what is dam first thing that comes to mind is a storage dam means to store water. This type of dam provides water supply and improves fish and wildlife. Storage dams also store water for hydropower generation, irrigation purpose, and flood control.
• Diversion dam: this kind of dam is constructed to divert the river or stream water into the off taking canals or channels. They create sufficient pressure which pushes water to ditches or canals or other diversion structures. Diversion dams are comparatively of low height and have a small reservoir. This type of dam is like a storage weir which also diverts the water for irrigation and has small storage space.
• Detention dams: the main function of detention dams are to store floodwater. It gives break to the flow of river water downstream during flood situations by storing it. And afterward, the stored water is released gradually after a flood as per the downstream channel capacity so it will not damage the downstream structure.
• Debris dam: this dam is constructed to stop the flowing and other debris like sand, woodblocks, gravel, etc.
• Cofferdam: this is a temporary dam constructed for a construction facility in dry space. It is generally constructed upstream of the main dam and water is diverted to a diversion channel for dam construction. Sometimes it also needs
• to constructed on the downstream side also.

Classification based on construction material:

• Earth fills dam: it is the oldest type of dam constructed and it consists of the local soil mostly. But this dam is not fully impervious. Water percolates through its soil body but is kept in check by a percolation line and hydraulic gradient line of percolation. Only one thing that makes it use lesser is that it can not be constructed for higher heights.
• Rockfill dam: these dams mostly consist the rock boulders but only boulders can not stop the water flow so an impervious layer needs to be provided upstream of dams. These are the less used dams.
• Concrete dams: this dam is constructed from plain concrete or reinforced concrete. They may be gravity dam, arch, etc.
• Masonry dams: these dams are made of brick masonry with cement mortar. These are mostly gravity dams.
• Steel dams: These kinds of dams are rarely used. They are used for small dams.
• Timber dams: this kind of dam serves the temporary purpose of storing water.

Classification based on structural design:

• Gravity dam: gravity dams are widely used dams. It is made of a concrete material which increases its weight and makes it able to resist horizontal water pressure on a dam. These dams are well suited for narrow valleys. As this dam stands on its weight to hold the water it needs a very good and strong foundation.
• Arch dams: These dams are known easily seen by their design the arch shape. It will create convexity on its upstream side by its shape so it transfers a load of water thrusts on the abutments of arch action. Its section will be similar to gravity, tringlur mostly. An Arch dam may have single or double curvature in the vertical plane. The most famous example is the hoover dam and the Idduki dam in India
• Buttress dam: there are three types of a buttress dam

Deck type: it has a sloping deck supported by a buttress. Buttress is nothing but triangular concrete walls which transfer water pressure from slab to foundation. It is also called a hollow dam because it does not consist solid concrete wall throughout. And the deck is a concrete slab supported by buttresses, which are spaced equally every 6 to 30 m.

Multiple arch type: here instead of deck arches are supported with buttresses made from concrete.

Massive head type: here no deck is available, in that case on the upstream side buttresses are flared which forms a massive head.

These dams are required less concrete than gravity dams. But cost vise they may or may not be cheaper. This work required more skilled labor.

• Embankment dams: these dams are either earth dams or rockfill dams which we have already discussed above in material-based dams.