Longest Dam in India

First Dam in India after Independence

Hirakud Dam is the longest dam in India (also, first dam in India after independence) located near Sambalpur district in the western part of the eastern state of Odisha. It is one of the first biggest river delta projects started immediately after the independence. The main purpose of the dam was to contain the flood waters of Mahanadi and to use it resourcefully for generating electricity and irrigation.

The length of the main section of the dam is 4.8 Km and it is flanked by dykes of nearly 21 kms on both sides earning it the credit of being the longest dam in India. The successful irrigational functioning of the dam has made Sambalpur the rice bowl of Odisha. Besides providing water for irrigation the dam serves various purposes like- generating electricity, containing floods etc.

Location of Hirakud Dam

The Hirakud Dam is located about 20 kms from the town of Sambalpur in west Odisha. The dam is easily accessible with a number of buses and taxis plying to the place. There is also a railway station in the vicinity of the dam. The dam and its large reservoir have kept the nature and wildlife surroundings it in its pristine form and attracts many tourists and nature lovers throughout the year. If you were to stand on the main section of the dam and looking at the reservoir and its surroundings, nothing can stop you from admiring the stunning beauty of the dam and the hills surrounding it.

Need to Construct Hirakud Dam

The main purpose of the dam was to contain the furious floods of Mahanadi which had a history of devastating floods; being a seasonal river it swells up during rains, destroying crops over thousands of acres of land and displacing millions in Odisha which is geographically located in the lower delta region of the river.

Such was the devastation brought upon by the river that before the construction of Hirakud Dam; Mahanadi was also called as ‘The Sorrow of Odisha’.  It was primarily to save loss of crops and lives due to floods that Sir M. Visvesvaraya proposed the construction of huge reservoirs to contain the flood waters of Mahanadi.

History of Hirakud Dam

Before the construction of Hirakud Dam, Mahanadi was called the sorrow of Odisha because of the devastating floods that it brought each year. Sir M. Visvesvaraya proposed a detailed study for the construction of reservoirs to contain the floods of Mahanadi. Sir M. Visvesvaraya is highly regarded as a brilliant Indian engineer of post-pre independence era. Sir Visvesvaraya had also supervised the successful construction of the Krishna Raj Sagar (KRS) Dam in Karnataka.

Based on the proposal of Sir M. Visvesvaraya; under the chairmanship of B.R. Ambedkar, the Member of Labour, it was decided in 1945 to fund the project with purpose of containing the floods as well as utilizing the water for useful purposes. The Central Waterways, Navigation and Irrigation Commission took up the work of construction. Pt. Jawaharlal Nehru, then the Prime Minister of India started the work by laying first batch of concrete on Apr 12, 1948.

 

The dam was completed and inaugurated by Pt. Jawaharlal Nehru on January 13, 1957. The total cost incurred for the completion of the project in 1957 was INR 1000.2 million and it was intended to irrigate 1350000 acres of land and producing 48 GW of electric power.

Structural and Technical Details of Hirakud Dam

The Hirakud Dam is built as a mixed structure of earth and masonry. Masonry is the work of laying stones, granites, lime stones etc. one over the other and binding them with concrete. The dam is an earth filled embankment; giving it more strength against the floods and also making it spill proof and water resistant. The dam is built across the Mahanadi and is located between two hills – Lakshmidungri and Chandilidungri on left and right respectively; if you were to stand on the main section looking at the reservoir.

The main section of the dam has a length of 4.8 kms and is flanked by dykes on both sides with a total length of 25.8 kms with dykes; making it the longest dam in India. The two observation towers built on the dam named- ‘Nehru Minar’ and ‘Gandhi Minar’ are a major source of attraction for those visiting the dam and provide a beautiful view of the lake.

There are two separate hydroelectric power houses supported by the dam. Power house I is located at the base of the main dam section and has 3×37.5 MW Kaplan turbine and 2×24 MW Francis turbine with a total installed capacity of 259.5 MW. The power house II is located about 19 kms from the main section at Chipilima and it houses 3×25 MW generators. The total installed capacity of the power houses is 347.5 MW.

Presently the dam houses 64 sluice gates in both sides spillways and 34 crest gates through which it releases 42450 cubic meter of water/second. The dam has a huge reservoir with capacity of 4779965 acre-feet with a catchment area of 83400 sq kms.

Relocation and Rehabilitation

Nearly 20000 families were relocated while the construction of Hirakud Dam and 150000 people were directly affected. The construction of dam was strongly opposed by 95 villages which were to be relocated and by some local politicians of that time. It was thought to be inappropriate to make Sambalpur suffer in order to save prosperous coastal regions from floods. Even the estimated compensation provided was reduced from INR 120 million to INR 95 million and ironically the total compensation provided was only INR 33.2 million ; almost a quarter of the estimate.

 

Advantages of the Hirakud Dam

The Hirakud Dam is a multipurpose dam which serves many useful purposes from containing floods to providing water for irrigation and generating electricity. Some of the main advantages of the Hirakud Dam are given below-

  1. a) Containing Floods

Mahanadi is a seasonal river which originates in the state of Chhattisgarh and flows through Odisha. During the monsoon season the Mahanadi used to swell up and unleash havoc in the lower delta region of Odisha mainly in the districts of Cuttack and Puri. The construction of the dam has directly saved around 9500 km2 of inhabited area from annual floods. This includes the land for settlements as well as irrigation.

  1. b) Irrigation Usefulness

The dam supports irrigation in 75000 km2 of land directly. Addition to that it also regulates 83400 km2 of drainage area of Mahanadi. The great reservoir has the capacity of 4779965 acre-feet having a total catchment area of 83400 km2. The dam supports huge cultivation of Rabi and Kharif crops in Sambalpur and Bargarh. It is due to the agriculture support provided by the dam that Sambalpur is called the ‘Rice Bowl of Odisha’.

  1. c) Electricity Generation

The total installed capacity of the two hydroelectric power plants that the dam supports is 347.5 MW. This electrical power is a main source of electricity to the districts of Sambalpur, Bolangir, Subarnpur and Bargarh and also to many industries set up in the region.

Some Interesting Facts about the Dam

  1. a) Submerged Temples

Before the construction of the dam there were nearly 200 temples in the villages around the dam. The villages were relocated and the temples now lie submerged completely under water with around 50 of them visible during summer when the reservoir water levels are low. Remaining most of the temples are destroyed due to being always submerged in water. The temples are a main attraction for tourists and scuba divers wanting to get a glimpse of glorious past.

  1. b) Cattle Island

The cattle island is another marvelous creation of the dam located at one of the extreme ends of the reservoir accessible by motor boats. It is near Kamarbandh village around 90 kms from the town of Sambalpur. During the construction of the dam, the relocated villagers had left some of their cattle behind, and the lower part of the hill got submerged under water making the island inhabited with cattle which took resident in the upper reaches of the island.

Surrounded by water on all the sides and living in the dense forest of the island; cattle have become wild and swifter than the domesticated ones. The Cattle Island is a major tourist attraction and provides a glimpse of nature in its pristine form.

  1. c) Wildlife

The dam with its network of channels and canals is supporting wildlife and nature in its purest form. It houses Debrigarh Wildlife Sanctuary located nearby. The sanctuary is home to many wild species like- leopards, wild boars, bisons, bears etc. Also the reservoir attracts many migratory birds and species like- red crested pochard, common pochard and several many. More than 75000 birds of 59 different species visit Hirakud Dam every winter which include ducks, common pochards; brown headed gulls and crested grebe.

FAQs On Hirakud Dam

Q1) Where is Hirakud Dam located?

Ans- Hirakud Dam is located 20 kms from Sambalpur, Odisha.

Q2) What was the main purpose for the construction of the dam?

Ans- The dam was constructed to save lower delta regions of Odisha from floods of Mahanadi.

Q3) Across which river is the Hirakud Dam constructed?

Ans- Hirakud Dam is constructed across the Mahanadi River.

Q4) How far is the dam from Sambalpur?

Ans- The dam is around 20 kms from Sambalpur.

Q5) Who proposed the initial plan for the construction of storage reservoirs in Mahanadi delta?

Ans- The plan was proposed by Sir M. Visvevaraya.

Q6) When was the project report of the dam submitted?

Ans- The project report of the dam was submitted to the government in June 1947.

Q7) Who took up the work for construction of the dam?

Ans- The Central Waterways, Irrigation and Navigation commission took up the work for construction of the dam.

Q8) At present which Government body looks after the functioning of the dam?

Ans- Odisha Hydro Power Corporation Limited, a gold rated state PSU (Public Sector Undertaking) incorporated under Companies Act 21.04.1995.

Q9) Who laid the first foundation stone setting the start of construction and when?

Ans – Then the Prime Minister of India Pandit Jawaharlal Nehru on 12 April 1948.

Q10) When was the construction of the dam was completed?

Ans – The construction of the dam was completed in 1957.

Q11) Who and when inaugurated the opening of the Hirakud Dam?

Ans- Then the Prime Minister of India Pt. Jawaharlal Nehru inaugurated the opening of the dam on 13 Jan 1957.

Q12) What was the complete cost of the project?

Ans- INR 1000.2 million in 1957.

Q13) What kind of structure is Hirakud Dam?

Ans- It is an earth filled embankment dam and a composite structure of earth and masonry.

Q14) What is the total length of the main section of the dam?

Ans- The total length of the dam’s main section is 4.8 kms.

Q15) What is the overall length of the dam including dykes?

Ans- Total length with dykes is 25.8 kms.

Q16) Between which two hills is the dam located?

Ans- Lakshmidungri on left and Chandilidungri on right.

Q17) What are the names of the two observation towers built on The dam?

Ans- Gandhi Minar and Nehru Minar.

Q18) How many Hydroelectric Power Houses do the dam supports?

Ans- The dam supports two Hydroelectric Power Houses.

Q19) What are the names and capacity of the two Power houses which the dam supports?

Ans-  Power House I – 259.5 MW and Power House II – 72 MW.

Q20) Where is Power House I located?

Ans- Power House I is located at the base of main section.

Q21) Where is Power House II located?

Ans- Power house II is located 19 kms south east of the dam at Chipilima.

Q22) How much is the total installed capacity of the dam?

Ans- Total installed capacity of the dam is 347.5 MW.

Q23) What is the reservoir capacity of the dam?

Ans- The reservoir of the dam has a total capacity of 47,79,965 acre-feet.

Q24) What is the total catchment area of the reservoir?

Ans- The reservoir has a total catchment area of 83400 sq km.

Q25) How many spillways are there in the dam?

Ans- The dam houses 64 sluice gates and 34 crest gates.

Q26) What is the total spillway capacity of the dam?

Ans- Total spillway capacity of the dam is 42,450 cubic meters per second.

Q27) What is total area of the reservoir lake?

Ans- The reservoir lake has a total surface area of 743 sq Km.

Q28) How much area was lost due to the construction of the dam?

Ans- Area of 596 sq Km was lost due to the construction of the dam.

Q29) How much is the top water level of the dam?

Ans- Top water level of the dam is 195.68 Mtr.

Q30) How much is the dead storage level of the dam?

Ans- Dead storage level of the dam is 179.83 Mtr.

Q31) How many villages were relocated for the construction of Hirakud Dam?

Ans- 95 villages had to be relocated to make way for the dam’s construction.

Q32) How much was the estimated compensation for those relocated?

Ans- A compensation of INR 120 Million was estimated for the affected.

Q33) How much was the actual compensation paid?

Ans- INR 33.2 Million was actually paid as the compensation.

Q34) Which river was named ‘The Sorrow of Odisha’?

Ans- Mahanadi was called ‘The Sorrow of Odisha’.

Q35) Why was Mahanadi called the ‘Sorrow of Odisha’?

Ans- Because during rains it brought floods to lower delta regions of Odisha.

Q36) How many canals does the dam has and what are their names?

Ans- The dam has three canals- Bargarh Main Canal, Sasan Canal and Sambalpur Canal.

Q37) Which industries do the water from Hirakud Dam is allocated to?

Ans- Mineral processing industries and thermal power plants in Sambalpur and Jharsuguda.

Q38) What effect does the siltation has on the reservoir capacity?

Ans- The siltation has reduced the reservoir storage capacity by 26%.

Q39) How much area does the dam saves from flooding?

Ans-  The dam saves around 9500 sq km of area from annual floods.

Q40) How much irrigation area does the dam supports?

Ans- Supports irrigation in 75000 sq Km of land.

Q41) Which major crops do the water from dam supports?

Ans- The dam supports Rabi and Kharif crops.

Q42) Which district is called the ‘Rice Bowl’ of Odisha and why?

Ans- Sambalpur is called as the ‘Rice Bowl’ of Odisha because of the successful irrigation provided by the Hirakud Dam.

Q43) How many temples got submerged due to the construction of the dam?

Ans- Around 200 temples got submerged under the water out of which around 50 are visible during summer.

Q44) Where is Cattle Island located?

Ans- Cattle Island is located at an extreme end of the reservoir.

Q45) What is peculiar about the cattle island?

Ans- Once domesticated cattle abandoned by the villagers are breeding in natural environment untouched by humans and have grown bigger and stronger than their domesticated ancestors.

Q46) Which wildlife sanctuary does the reservoir supports?

Ans- Debrigarh Wildlife Sanctuary.

Q47) How many migratory birds visit the reservoir in every year?

Ans- Nearly 75000 birds from 59 different species visit the reservoir every year.

Q48) In which season do the migratory birds visit the reservoir?

Ans- During the winter season.

Q49) Name some of the major species of birds visiting the Hirakud reservoir?

Ans- Common Pochard, Red Crested Pochard, Brown Headed Gulls and Crested Grebbe.

Q50) Hirakud reservoir is planned to be linked with which ambitious project of Government of India?

Ans- Indian Rivers Inter-link Project.

Q51) When and how many commemorative stamps were issued on Hirakud Dam?

Ans- On Oct 29, 1979 by the Department of Posts, 3 million stamps were issued to commemorate the dam.

Q 52) Which RBI governor issued a 100 Rs note to commemorate the dam and when?

Ans- H.V.R. Iyenger on Dec 26, 1960.