Advantages Of Dams
May 08, 2023, 16:45 IST
A dam is a barrier constructed across a river or any natural water body where excessive water is stored to conserve water and prevent water shortage in the non-monsoon season.
The gates of the dam shut or release the flow of water. Dams serve many purposes. They can control water flow during floods, they are used to generate electricity, and some dams are constructed for irrigation and navigation.
Based on height, the dams are classified as small dams, medium-sized dams, and large dams.
These small dams are constructed in a small area where there is a reduction in the flow of water as well as reducing soil erosion. These dams are mainly constructed in hilly regions, so the power generated is very high. Sometimes the power generated is so much that it can be sold to the national grid.
Types of small dams
-
Check dams -
These are small manmade dams constructed with concrete or just sandbags.
-
Micro-hydro -
These can generate a power of up to 5-100 KW, 5-100 homes are powered by this type.
-
Mini hydel -
These can generate a power of up to 100 KW – 1MW; it is slightly bigger than micro-hydro to power 100-1000 homes.
-
Small dams -
These can generate a power of up to 1MW – 10 MW; this is the largest of all types and can power 1000-10,000 homes.
Advantages of small dams
-
They involve a very small area, making it easy to construct and cost-effective.
-
It reduces the velocity of water; therefore, it prevents the siltation of water, so all the soil, dirt, and earth that comes with the water is washed along with the water.
-
It is eco-friendly as it involves much less area, so fewer trees are cut down fewer animals are harmed.
-
These are the dams in which a range of mountains bring in the water. There are waterfalls on every mountain. These waterfalls collectively lead to the formation of large dams.
-
In large dams, there are so many inlets for water, but the water flows down only through one outlet a wall.
-
In this, the hydroelectric dam consists of penstocks. Through the penstocks, the water released by great pressure from height water is coming down, which is how power is generated in them.
Advantages of large dams
It comprise the reservoir, and this reservoir gets filled with water during the rainy season. The water is available throughout the year, so the cash crops like paddy and sugar cane which need a lot of water for their growth thrive well.
Examples
-
The largest dam in India is the Bhakra Nangal dam, constructed over the Sutlej river of Bhakra village near Bilaspur, Himachal Pradesh.
-
The longest dam in India is the Hirakud dam, constructed across the Mahanadi of Sambalpur district, Odisha.
-
The oldest dam in India is the kallania dam, also called the grand anicut, constructed across the Kaveri river in Tamil Nadu.
These types of dams are unusual and medium-sized. Based on the material used, it is further divided into
-
Timber Dams
: In these types of dams, the primary component used is wood or fir. These are mostly built in the small town to store water.
-
Embankment dams
: These are of two types depending upon the type filled the earth or the rock. One such embankment dam in India is The Tehri dam constructed across the Bhagirathi river of the tehri district of Uttarakhand.
The dams are primarily used for storing and conserving water.
The dams are useful for power generation. The power is generated when the water flows from the higher to the lower end; if the water flow is really good, they can sell the current to the national grid. Some of the hydroelectric power plants in India are the Tehri hydropower plant, the Kona hydropower plant, and the Naptha jakri dam.
In the dams the velocity of water is reduced; therefore it prevents siltation; when siltation is prevented all the soil, dirt, and earth, which comes along with the water is washed along with the water this soil becomes very fertile for irrigation purposes.
The dam consists of a big reservoir on the back side of it where water is stored during the rainy season and that water is made available throughout the year so in drought conditions also this water is released through the sluices.
Some dams constructed to prevent drought in India are the Aklera Sagar dam constructed over the Chambal river in Rajasthan and the Abhaypura dam built across the bhimrat river in Rajasthan.
The soil around the dam is very fertile as it is washed along with the water, so it helps the farmers for good plant growth; it also promotes the growth of cash crops such as paddy fields and sugar cane which need water throughout the year, so it helps in cash crops thrive well.
The dams are also a great site for tourist attractions and provide restoration to human beings. Many water sports and other water activities are available, making the dams more beautiful and a major site for tourist attraction. Some tourist spot dams are the Indira Sagar dam in Madhya Pradesh, and the Idukki dam in Kerala.
Q1. What is a dam used for?
Ans.
A dam's main function is to hold water, wastewater, or other liquid-borne materials for various purposes, including flood control, water supply for people and livestock, irrigation, energy production, mine tailings containment, recreation, or pollution control.
Q2. What are the advantages of dams?
Ans.
Recreation, flood control, water supply, hydroelectric power, waste management, river navigation, and wildlife habitat are some economic, environmental, and social benefits of dams.
Q3. How do dams prevent floods?
Ans
. There is space to store extra rainwater during the monsoon season and for water to be released in a controlled manner, reducing floods downstream when there is heavy inflow to the dams.
Q4. What are the effects of dams?
Ans.
Large dams have numerous irreversible negative effects, including the extinction of numerous fish and other aquatic species, the disappearance of birds from floodplains, significant losses of cropland, wetlands, and forests, and the erosion of coastal deltas.
