According to the Center Water Commission, India is the home of over 5,200 major dams. But all of these dams are not built equal. In fact, we can classify these dams into different types and categories, based on many things. Such as how they are constructed, and what they are used for. So, here is the list of India’s most common types of dams that you didn’t know existed.
These types of dams are made of readily available natural materials, like soil, sand, clay, or rock. Concrete or any other binding agent is not used to mix these materials. These types of dams are often equipment-intensive rather than labor-intensive, as mixing and compacting the materials need heavy machinery.
Embankment dams also come in two types: the earth-filled dam and rock-filled dams. You can see many dams of this type throughout India. One big example is the Tehri dam, which is built on the Bhagirathi river. It’s the largest rock & earth-fill embankment dam in India. It’s 1,886 ft long, and 855 ft high.
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These types of dams are built with one primary purpose in mind. That is to store the excessive water during monsoon season. These dams are also used for supplying water for irrigation facilities, providing drinking water, or even improving habitat for fish and nearby wildlife. Every dam can be classified as a Storage dam because they all have some sort of water storing capacity.
In India, the Indira Sagar Dam is the largest Storage dam. Built on the Narmada river, this dam has a capacity of storing 12.22 billion cubic meters of water. It’s said that a town of 22,000 people and 100 villages were displaced, just to build the dam.
Today most modern mega-dams are built with concrete as it has more strength than other materials. Dams built with concrete and cement mixture do not fail suddenly, and their failure can be predicted well in advance. Also, these dams are very cost-effective as their maintenance expenses are not as high as others.
We classify a dam as “Concrete Dams” based on how they are constructed. Therefore, you can put other dams in this type. For example, a “Storage Dam” can also be a “Concrete Dam”, if it is made of concrete.
Sardar Sarovar Dam is the largest concrete dam in India, built on the Narmada river. It’s also called – The Lifeline Of Gujarat. This is the second-largest dam in the world regarding volume and size, with the highest spillway discharge capacity of 20.7 lakh cumecs.
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These types of dams are constructed for diverting all or a portion of the flow of a river from its natural path. Diversion dams don’t usually store or hold water in a reservoir. Instead, they artificially channel the water flow into other pre-planned directions.
Diverting a river’s water flow into another direction from its natural course has its benefits. Such as, reviving a drought-prone land by supplying the water for irrigation, generating hydro-powered electricity, or facilitating drinking water.
Kallani dam is an ancient dam in India, that is classified as Diversion Dam. It’s also known as the Grand Anicut. It was built during the period of the Chola dynasty, in 100 BC – 100 AD making it the 4th oldest water regulator in the world. The purpose of the dam construction was to originally divert the waters of the Kaveri river to the delta district to facilitate irrigation.
These types of dams are especially built to fight against floods by collecting the excessive river water from overflowing. Detention dams are very common in flood prone areas. These dams collect flood water, and channel it to different destinations to prevent overflowing.
No dams have only one purpose, this type of dams is also no different. Beside controlling floods, Detention dams are used to store water for irrigation facilities, or fishing. These dams usually release the stored water gradually.
Built on the Mahanadi River, Hirakud dam is the longest Detention dam in India. It has a total length of 4.8 km. It was constructed in 1936, after a devastating flood happened in the state of Orisha.
Rockfill dams are commonly built from dumped and compacted rock fills. Therefore, these dams are appropriate at locations where suitable rocks can be found from nearby areas.
These dams are very suitable at locations, where concrete dams can not be made for the lack of a strong foundation. Also Rockfill dams can be constructed with low skilled labour. These dams can be very tall, because of their higher strength.
Built on the Bhagirathi river, the Tehri dam in Uttarakhand is a great example of rockfill dams. It comes under the list of tallest dams in India. It’s 855 ft high, and 1,886 ft wide. The dam is now used for withholding a reservoir for irrigation, drinking water, and the generation of 1,000 megawatts of hydro-powered electricity.
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Arch dams are a type of curved shaped concrete dam. These dams are constructed where river valleys are formed. The curved rounded shape of these dams help bear the immense water pressure. These dams are thinner than other types of dams, and mostly built with concrete.
For their U-shaped design, the balance of the water load is transferred to the foundation by cantilever action. However, these dams require strong foundations on both sides of the “U” curve to resist the force.
Idukki dam is a great example of Arch dam in India. It is built across the Periyar river in a narrow gorge between two granite hills. This dam is a double curvature Arch dam and located in Kerala, India. The dam supports a 780 megawatts hydro-electric power station, which is owned by the Kerala State Electricity Board.
Gravity dam is one type of dam, built to hold back water by only using the weight and strength of the materials that they are constructed of. The dam uses the resistance of the constructed material against the foundation to oppose the horizontal pressure of water pushing against it.
This type of dam requires a stiff rock foundation to bear the high water pressure. Although concrete and cement are also used as a binding agent to increase the bearing strength of the structure.
Bhakra dam is a great example of concrete gravity dam in India. It’s constructed on the Sutlej river in Bilaspur, Himachal Pradesh. This gravity dam is the third largest reservoir in India. In terms of water storing capacity, the dam can hold up to 9.34 billion cubic metres of water.
These types of dams are built with the help of masonry of bricks and stone blocks, sometimes also with mortar to bind the stones. These dams are usually seen with a large and wide foundation, if compared to other dams. Masonry dams directly fall under the category of Gravity dam or Arch-gravity dams.
Located in Andhra Pradesh, the Nagarjuna Sagar Dam is the largest masonry dam in the world. The dam is constructed on the Krishna river. The dam has a capacity of holding 11.47 billion cubic meters of water. Its scenic beauty and religious importance make the dam one of the most popular tourist destinations in India.
* Images are sourced from – wikimedia.org | CC BY.